Garumbatitan morellensis, Mocho & Escaso & Gasulla & Galobart & Poza & Santos-Cubedo & Sanz & Ortega, 2024

Mocho, Pedro, Escaso, Fernando, Gasulla, José M., Galobart, Àngel, Poza, Begoña, Santos-Cubedo, Andrés, Sanz, José L. & Ortega, Francisco, 2024, New sauropod dinosaur from the Lower Cretaceous of Morella (Spain) provides new insights on the evolutionary history of Iberian somphospondylan titanosauriforms, Zoological Journal of the Linnean Society 201 (201), pp. 214-268 : 220-248

Garumbatitan morellensis spnov.

( Figs 4–23 , Supporting Information, File S1)

Zoobank: urn:lsid:zoobank.org:act:2D373FD9-6A97-453C-B2EB-8D5E259876FD

Holotype: The largest individual found in Sant Antoni de la Vespa, whichcomprisesanarticulatedposteriorcervical-to-anteriordorsal vertebrae sequence (SAV08-100) and a partial dorsal centrum (SAV08-040); dorsal ribs (SAV08-101, SAV08-102, SAV08-103), anterior-to-posterior caudal vertebrae (SAV05-027, SAV05-028, SAV05-029, SAV05-030, SAV05-060va, SAV05-061, SAV08- 060-061-063-065-067-066-064-068-069-070-071, SAV08-047, SAV08-048, SAV08-049, and SAV08- 050), six chevrons (SAV05- 060chb, SAV05-063, SAV05-060cha, and SAV05-060chc, two are included in SAV08-060-061-063-065-067-066-064-068-069-070- 071), an interclavicle (SAV05-055), left (SAV05-023) and right (SAV05-024) femora, left (SAV05-025) and right (SAV05-065) tibiae, left (SAV05-026) and right fibulae (SAV05-064), right astragalus (SAV05-066), and an almost complete right pes (SAV05- 068), and left metatarsal II ( SAV05-021 ) and IV ( SAV05-024 ). The articulated posterior cervical-to-anterior dorsal vertebrae sequence (SAV08-100) is still unprepared, as well as other jackets with elements from the holotype, including some dorsal ribs (SAV08-30-46), nine caudal vertebrae, and two chevrons (SAV08- 060-061-063-065-067-066-064-068-069-070-071), a partial ilium (SAV08-104), left femur (SAV05-023), left tibia (SAV05-025), and left fibula (SAV05-026).

Etymology: morellensis refers both to the ‘Arcillas de Morella’ Formation and to the town of Morella, where some of the first dinosaur remains in Spain were found and where the Sant Antoni de la Vespa fossil site is located.

Type locality and horizon: Sant Antoni de la Vespa fossil site, Morella, Castelló ( Spain), Arcillas de Morella Formation, late Barremian in age, Maestrat Basin.

Diagnosis: The somphospondylan titanosauriform Garumbatitan morellensis can be diagnosed by 11 autapomorphies (marked with an asterisk), as well as eight local autapomorphies: (i) lateral pneumatic fossae in the anterior caudal centra [also shared with the somphospondylan Savannasaurus elliottorum, Poropat et al. (2020) ]; (ii) posterior articular surface is more deeply concave than anterior one in anterior-middle caudal centra; (iii) depression near the anterior edge of the centrum and above the lateral crest in the middle-posterior caudal vertebrae*; (iv) middle-posterior caudal vertebral pedicels covered by a complex of three anteroposteriorly elongated ridges*; (v) middle-posterior caudal neural spines are expanded posteriorly, which results in lateral rounded boss*; (vi), femur with a lateral developed lateral bulge (44% of the transverse minimal width of the femoral shaft)*; (vii) the trochanteric shelf is proximolaterally-to-distolaterally oriented*; (viii) presence of a linea intermuscularis cranialis in the femoral anterior face and interrupted at its midlength; (ix) ratio of the mediolateral breadth of the tibial condyle to the breadth of the fibular condyle of the femur is 0.8 or less; (x) medial face of fibular diaphysis is concave transversely along its length, resulting in a D-shaped cross-section with a concave medial border, being bordered by two ridges (shared with some titanosaurs)*; (xi) absence of calcaneum; (xii) the metatarsals II, III, and IV are more gracile and significantly longer than the metatarsals I and V with an abrupt transition between metatarsals I and II and between metatarsals IV and V, which is well visible in dorsal view, resulting in the retraction of the most medial and lateral toes*; (xiii) metatarsal I with a tubercle on medial surface (situated at approximately midlength and equidistant from the dorsal and the ventral margins); (xiv) the proximal tip of the ventrolateral crest of the metatarsal II is laterally deflected and projected*; (xv) pronounced tuberosity near the ventromedial edge of the metatarsal V distal end; (xvi) lateral depression near the dorsolateral ridge of the distal end of pedal phalanx I.1*; (xvii) proximal surface of the phalanx II.1 has an ‘heart’-shaped outline*; (xviii) digit III with a reduced ungual (33% of the metatarsal III length)*; and (xix) loss of the pedal phalanges in the digit V.

Paratype: A partial skeleton comprising dorsal ribs (SAV05-046, SAV05-047), left (SAV05-031a) and right (and SAV05-031b) pubes and two almost complete hindlimbs, which include the left (SAV05-031) and right (SAV05-013) femora, the left (SAV05- 036) and right (SAV05-032) tibiae, the left (SAV05-037) and right (SAV05-033) fibulae, a right astragalus (SAV05-034), one almost complete right pes (SAV05-035.a-l and SAV05-038.b), and some elements from the left pes (SAV05-035.m, SAV05- 038.a and SAV05-038.c).

Referred material: One left metatarsal I (SAV05-044), metatarsal III (SAV05-056), and metatarsal IV (SAV05-058), and one left pedal phalanx I.1 (SAV05-057.b) and I-V (SAV05-057.c).

Description

Presacral vertebra:

An almost complete sequence of possible posterior cervical to anterior dorsal vertebrae from the holotype individual is preserved; however, these vertebrae still need to be prepared. Only a part of the posterior section of a dorsal centrum is available for study (SAV05-40, Fig. 4A–E ), which is interpreted as belonging to a middle or posterior dorsal vertebra. This centrum preserves a concave posterior articular surface, which is markedly dorsoventrally compressed (partially owing to taphonomy). The ventral surface is smoothly transversely convex. The ventral margin of the pneumatic fossa is preserved. The centrum is fractured, making it possible to observe internal camellate tissue bone. This type of tissue is also present in the cervical-to-dorsal sequence found in this fossil site. The presence of a camellate tissue bone in the presacral vertebrae was considered as a synapomorphy of Galveosaurus + Titanosauriformes (e.g. Wilson 2002, Upchurch et al. 2004, Carballido et al. 2011b, Mannion et al. 2013).

Dorsal ribs:

Our description of the dorsal ribs is based on five partial dorsal ribs ( Fig. 4F–Q ) from the holotype (three anterior left ribs: SAV08-101, 102, 103) and paratype (one right anterior rib SAV05-047, and one right middle rib SAV05-046). The anterior ribs are the larger elements of the set. The proximal edge is poorly preserved in all elements and only SAV05-046 preserves a complete distal end ( Fig. 4N, O ). The proximal end has a triradiate cross-section, which corresponds to three well-developed proximodistal crests: (i) the anteromedial to medial crest; (ii) anterior crest; and (iii) posterior crest. The anteromedial to medial crest extends from the capitulum, which is anteromedially located, and deflects to the midpoint of the medial surface in the anterior half of the rib, being the most robust of the forementioned crests. The posterior and anterior crests correspond to the edges of the lateral surface, and the posterior edge is generally thinner and more acute than the anterior one. The anterior ribs are marked by a flat lateral face in proximal-to-middle section of the shaft (probably for the reception of the scapula), which is slightly anteroposteriorly expanded (e.g. Fig. 4H, I ). Between the posterior and the anteromedial crests, the rib is markedly concave, corresponding to the posteromedial fossa. This fossa is dorsoventrally elongated and bears a crenulated surface and some foramina ( Fig. 4F, G ). The posteromedial fossa is dorsally bordered by a thick and robust ridge, which departs from the anteromedial crest to the posterior crest probably connected to the tuberculum. The anteromedial surface of the proximal end, bordered by the anterior and anteromedial crests, is less concave than the posteromedial fossa, and referred to the anteromedial fossa (no crenulated surface and foramina are present). The proximal end of the rib preserves several internal camerae (following: Wedel et al. 2000, Wedel 2003). The presence of a pneumatic foramen and internal cavities in the dorsal ribs was considered as a synapomorphy of Titanosauriformes ( Wilson and Sereno 1998, Wilson 2002, Mannion et al. 2013), which is present in the Iberian Early Cretaceous titanosauriforms Tastavinsaurus sanzi ( Royo-Torres et al. 2012) and Europatitan eastwoodi ( Torcida Fernández-Baldor et al. 2017) . In the middle section of the rib, the anteromedial crest, located at midpoint of the anteroposterior width of the medial surface of the rib shaft, becomes smoother and disappears. Additionally, the antero- and posteromedial fossae converges into a medial flat surface of the rib shaft, in the middle section of the rib, which quickly becomes transversely concave to the distal end. In the middle section of the more distal anterior dorsal rib of the holotype (SAV08-101) and in the anterior one of the paratype (SAV05-047) specimens, the anterior crest bifurcates, resulting in a second crest, which extends distally to the lateral side of the rib. In the middle and distal sections of the rib, the shaft becomes extremely compressed mediolaterally (the anteroposterior width is more than three times the mediolateral one) with acute anterior and posterior edges, and a flat-to-slightly concave medial and lateral surfaces ( Fig. 4J ). The presence of anterior dorsal ribs with a plank-like cross-section (i.e. anteroposterior width more than three times the mediolateral one) was considered as characteristic of Titanosauriformes ( Wilson and Sereno 1998, Wilson 2002).

In the middle dorsal rib ( Fig. 4N, O ), the proximal end is also triradiate. The anteromedial crest is anteriorly displaced and expands in the direction of the capitulum, which is anteroposteriorly expanded. The antero- and posteromedial fossae of the proximal end are both concave, and the surface is damaged, which reveals a highly pneumatized internal tissue bone, composed of small camerae and camellae (following: Wedel et al. 2000, Wedel 2003). The anteromedial crest departs from the proximal end and extends distally to the anterior edge of the rib. The posterior pneumatic fossa of the proximal end contains foramina, and extends to the medial surface of the shaft, which is anteroposteriorly concave up to the distal end. Proximally, the anterior crest deflects to the lateral surface of the proximal end, and at the distal end, it also deflects to the lateral surface of the rib, being smoother, resulting in an anteroposterior convex lateral surface. The posterior crest of the proximal end remains in the same position along the proximodistal width of the rib. The distal end is less transversely compressed than the distal end of the anterior dorsal ribs (anteroposterior width is two times the mediolateral one).

Anterior caudal vertebra:

Five anterior caudal vertebrae and two isolated neural spines are described herein ( Figs 5 , 6A–F ), which were found near the hindlimbs of the holotype specimen. They belong to the distal half of the anterior series, and their positions are estimated based on other titanosauriform specimens with reasonably complete caudal series (e.g. Janensch 1950, Royo-Torres et al. 2012, Mocho et al. 2017a). The four more anterior ones were found in articulation above the femur of the holotype specimen (SAV05- 027: ≈eighth caudal vertebra, Fig. 5A–F ; SAV05-028: ≈9th caudal vertebra, Fig. 5G–L ; SAV05-029: ≈10th caudal vertebra, Fig. 5M–R ; SAV05-030: ≈11th caudal vertebra, Fig. 5S–X ), plus a more distal anterior caudal vertebra (SAV05-060va ≈ 12th caudal vertebra, Fig. 6A–F ). The chevrons described below were found near these vertebrae. The neural arches of the first four preserved caudal vertebrae are heavily damaged. SAV05- 027 preserves a centrum with a flat posterior articular surface with a depression in the centre ( Fig. 5D ). The presence of a flat posterior articular surface is common in non-titanosaurian macronarians such as Camarasaurus supremus ( Osborn and Mook 1921) , Lourinhasaurus alenquerensis , Brachiosaurus altithorax ( D’Emic 2012) , Cedarosaurus weiskopfae ( Tidwell et al. 1999) , and Aragosaurus ischiaticus ( Royo-Torres et al. 2014) . The anterior caudal vertebrae of Tastavinsaurus sanzi have a flat surface that bears a central concavity ( Royo-Torres 2009), as in Lourinhasaurus alenquerensis and SAV05-027. All the caudal vertebral centra of Europatitan eastwoodi are described as amphicoelous ( Torcida Fernández-Baldor et al. 2017), differing from the condition of SAV05-027 and, also from the anteriormost caudal vertebrae of Tastavinsaurus sanzi ( Royo-Torres 2009) . The remaining anterior caudal vertebrae of Garumbatitan morellensis are amphicoelous, i.e. the anterior and posterior articular surfaces are concave, becoming smoothly concave in the last anterior centra (the anterior articular surface becomes less concave than the posterior one). The presence of a less concave anterior articular surface than the posterior one, is a common trend in rebbachisaurids ( Carballido et al. 2012, Mannion et al. 2019b), but also present in some somphospondylans such as Huabeisaurus allocotus , Gobititan shenzhouensis , Huanghetitan ruyangensis , Jiangshanosaurus lixianensis , Phuwiangosaurus sirindhornae , Savannasaurus elliottorum , Tangvayosaurus hoffeti , and Wintonotitan wattsi (e.g. D’Emic et al. 2013, Poropat et al. 2016, Mannion et al. 2019a). The average elongation index value [aEI, the anteroposterior length of centrum (excluding articular ball) divided by the mean average value of the mediolateral width and the dorsoventral height of the posterior articular surface of the centrum (following: Upchurch 1995, 1998, Chure et al. 2010)] is around 0.80–1.12 in the preserved anterior caudal vertebrae of Garumbatitan morellensis , which fits with the range shown by the anterior caudal vertebrae of Tastavinsaurus sanzi (aEI: 0.52–1.21, Royo-Torres et al. 2006) but much larger than the range shown by Eeuropatitan eastwoodi (aEI: 0.56–0.68, Torcida Fernández-Baldor et al. 2017). A circular and small tuberosity is present in the centre of the posterior articular surface of SAV05-060va [ Fig. 6D ; no tuberosities are present in Eeuropatitan eastwoodi ( Torcida Fernández-Baldor et al. 2017) and they can be present in some middle caudal vertebrae of Tastavinsaurus sanzi ( Royo-Torres 2009) ], and Savannasaurus elliottorum ( Poropat et al. 2020) . The anterior articular surface is mediolaterally wider than dorsoventrally tall, and the maximum mediolateral width is ventrally displaced, which markedly differs from the morphology of the anterior articular surface of the anterior caudal vertebrae of Tastavinsaurus sanzi ( Royo-Torres 2009, maximum mediolateral width is dorsally displaced) or Europatitan eastwoodi ( Torcida Fernández-Baldor et al. 2017, with a subcircular anterior articular surface). The posterior articular surface is also wider than tall.

The lateral surface is anteroposteriorly concave and dorsoventrally convex, converging ventrally, resulting in a transversely narrow ventral surface. In SAV05-028 appears a longitudinal ridge in the lateral surface below the caudal rib and the lateral fossa ( Fig. 5I ). This ridge displaces ventrally in the following centra, occupying a more ventrolateral position in the transition with the middle caudal vertebrae. In SAV05-060va, another lateral ridge appears in lateral surface of the centrum, below the caudal rib. Near the anterior and posterior edges of the centrum, the lateral surface is covered by some rugosities. Bellow the caudal rib there is a shallow fossa, interpreted as pneumatic. Small foramina can be present in some of the fossae. The presence of pneumatic fossa lacking sharply defined margins on the lateral surface of anterior caudal vertebrae was recovered as a synapomorphy of Brachiosauridae ( D’Emic 2012, Mannion et al. 2013), which can be present in some vertebrae of Tastavinsaurus sanzi and other somphospondylans such as Savannasaurus elliottorum and Padillasaurus leivaensis , being absent in Europatitan eastwoodi ( Carballido et al. 2015, Mannion et al. 2019 a, Poropat et al. 2020). The presence of this foramina has been recorded in other non-titanosaurian somphospondylans such as Savannasaurus elliottorum , Chubutisaurus insignis , and Gobititan shenzhouensis ( Mannion et al. 2019 a, b, Poropat et al. 2023). Also, the presence of small, shallow vascular foramina in lateral and ventral surfaces of anterior-middle caudal centra was recovered as synapomorphy of Titanosauriformes ( Mannion et al. 2013); however, their absence seems to be characteristic of some brachiosaurids such as Cedarosaurus weiskopfae ( Mannion et al. 2013) , Galveosaurus herreroi ( Pérez-Pueyo et al. 2019) , Soriatitan golmayensis ( Royo-Torres et al. 2017a) , and the possible brachiosaurid Europasaurus holgeri ( Mannion et al. 2013; recovered as a basal macronarian by Carballido et al. 2020), but present in Giraffatitan brancai , Vouivria damparisensis , Lusotitan atalaiensis , and several other somphospondylans ( Mannion et al. 2019a, b). These foramina are absent in Tastavinsaurus sanzi ( Mannion et al. 2013) . The ventral surface is transversely concave between the posterior chevron facets, becoming flat anteriorly (in the ventral surface of SAV05-027 and SAV05-029 there is an anteroposterioly short ridge departing from the posterior chevron facet). The anterior chevron facets are eroded, but they seem to be well-developed. Several foramina are visible on the ventral surface. The neural canal is dorsoventrally taller than it is wide transversely with a quadrangular outline (straight ventral and lateral edges, and concave dorsal one; taphonomic deformation might have played a role in the morphology of the neural canal). Behind the pedicels there are two small depressions in the dorsal surface of the centrum, as well as a tuberosity, which is present up to the middle caudal vertebrae. There is a longitudinal ridge in both sides of the ventral surface of the neural canal near the pedicels. The dorsal surface of the neural canal is excavated in SAV05-030.

The caudal ribs are still dorsoventrally tall in SAV05-027 and SAV05-028, and they extend to the lateral surface of the neural arch ( Fig. 5D, J ). In the posterior surface of the caudal rib there is a ridge that is interpreted as the postzygodiapophyseal lamina (podl). The caudal ribs are laterally projected in posterior view and posterolaterally projected in dorsal view, deflecting posteriorly in the tip as occur with Tastavinsaurus sanzi ( Royo-Torres 2009) . In the preserved anterior caudal vertebrae, the caudal ribs do not reach the posterior articulation. The posterior deflection of the caudal ribs is a common feature in titanosauriforms, extending beyond the posterior end of centrum in Abydosaurus mcintoshi , Andesaurus delgadoi , Cedarosaurus weiskopfae , Chubutisaurus insignis , Europatitan eastwoodi , Giraffatitan brancai , Sonorasaurus thompsoni , Soriatitan golmayensis , Tastavinsaurus sanzi , and Tangvayosaurus hoffeti (e.g. Mannion et al. 2013, 2019a, b, D’Emic et al. 2016, Royo-Torres et al. 2017a); this differs from the condition preserved in SAV05-027. The caudal rib is dorsoventrally compressed in the last anterior caudal vertebrae, and they change from a sub-horizontal orientation to an anterodorsal-posteroventral one, in lateral view. The caudal rib is supported anteroventrally by a developed anterior centrodiapophyseal lamina (acdl) and posteroventrally by a rudimentary posterior centrodiapophyseal lamina (pcdl). Both laminae are rudimentary in the remaining anterior caudal vertebrae. The presence of acdl in anterior caudal vertebrae were recovered as a synapomorphy of Flagellicaudata ( Tschopp et al. 2015), but it was identified in other sauropods taxa, including the brachiosaurids Giraffatitan brancai , Vouivria dampariensis , and non-titanosaurian somphospondylans Europatitan eastwoodi , Phuwiangosaurus sirindhornae , Tastavinsaurus sanzi , and Jiangshanosaurus lixianensis ( Mannion et al. 2017, 2019a, b).

The anterior neural arch is anteriorly displaced but does not reach the anterior edge of the anterior articular surface of the centrum. The lateral surface of the pedicels is covered by rugosities. The pedicels are transversely compressed.The prezygapophyseal processes are anteriorly projected, transversely compressed, and surpass the anterior edge of the anterior articular surface of the centrum. The medial surface is flat whereas the lateral one is transversely convex. The spinoprezygapophyseal lamina (sprl) is single, connected to the prezygapophyseal facets but restricted to the base of the neural spine. There is no lateral tuberosity in prezygapophyseal processes as occur in some titanosaurs ( Díez Díaz et al. 2016, González Riga et al. 2016, 2018). The ‘spinoprezygapophyseal lamina-process’ observed in some titanosauriforms (e.g. Giraffatitan brancai and Mendozasaurus neguyelap ) and Losillasaurus giganteus ( D’Emic 2012, Mannion et al. 2019a) is absent in Garumbatitan morellensis . Between the sprl there is a ventrally deep spinoprezygapophseal fossa (sprf), which is ventrally bordered by the intraprezygapophyseal lamina (tprl). The anterior surface of the neural spines is completely covered by the rugosities of the prespinal lamina (prsl, not medially restricted). The postzygapophyseal processes are posteriorly projected from the neural spine and the pedicels, almost reaching the posterior articular surface of the centrum [more posteriorly projected than in Tastavinsaurus sanzi ( Royo-Torres 2009) and Europatitan eastwoodi ( Torcida Fernández-Baldor et al. 2017) ]. A spinopostzygapophyseal lamina (spol) extends from the dorsal edge of the postzygapophysis up to the distal end of the neural spine, and borders the spinopostzygapophyseal fossa (spof), which is covered by the rugosities of the postspinal lamina (posl). The morphology of the neural spine can be described based one complete neural spine from the 12th caudal vertebra (SAV05-060va) and from two broken and isolated neural spines recovered near SAV05- 029 and SAV05-030. In anterior view, the neural spines are only slightly expanded and have a round dorsal edge. The posterior surface is wider than the anterior one. No dorsal grooves or lateral depressions are present as in Aragosaurus ischiaticus ( Royo-Torres et al. 2014) and Oceanotitan dantasi ( Mocho et al. 2019a) . The lateral surface is flat and covered by some smooth rugosities near the tip. In the 12th caudal vertebra, the neural spine is subvertical, similar to the holotype of Tastavinsaurus sanzi ( Royo-Torres 2009) ; however, in the more anterior ones of Garumbatitan morellensis , probably from the 8th to 11th position, the neural spines are interpreted as posterodorsally oriented as in Europatitan eastwoodi ( Torcida Fernández-Baldor et al. 2017) and in the anteriormost caudal vertebra of Soriatitan golmayensis ( Royo-Torres et al. 2017a) , differing from the anterodorsally oriented neural spines of Tastavinsaurus sanzi ( Royo-Torres, 2009) , Cedarosaurus weiskopfae ( Tidwell et al. 1999, DMNH 39045), and Venenosaurus dicrocei ( Tidwell et al. 2001, DMNH 40932). The recovered neural spines are not as anteroposteriorly expanded as the more distal anterior caudal vertebrae of Europatitan eastwoodi ( Torcida Fernández-Baldor et al. 2017) .

Middle caudal vertebra:

SAV05-061 corresponds to one of the first middle caudal vertebrae (probably the 16th caudal vertebra, Fig. 5G–L ); however, there is a series of nine middle caudal vertebrae that still need to be prepared (SAV08-060-061-063-065-067-066-064-068- 069-070-071). This vertebra preserves a peculiar morphology, which is also present in the first middle caudal vertebrae of Tastavinsaurus sanzi . The centrum is amphicoelous, i.e. the anterior and posterior articular surfaces are concave ( Fig. 6G–J ). No important tuberosities of pits are present in the articular surfaces. The anterior and posterior articular surfaces of the centrum are dorsoventrally compressed [much more than in Tastavinsaurus sanzi ( Royo-Torres 2009) and Europatitan eastwoodi ( Torcida Fernández-Baldor et al. 2017) and differing from the transversely compressed articular surface of Soriatitan golmayensis ( Royo-Torres et al. 2017a) ], with a straight dorsal and smoothly pointed lateral edges unlike the other Iberian titanosauriform taxa (e.g. Royo-Torres 2009, Mocho et al. 2017a, Royo-Torres et al. 2017a, Torcida Fernández-Baldor et al. 2017). The aEI of SAV05-061 is 1.15. The lateral surface of the centrum is anteroposteriorly concave and marked by two longitudinal ridges ( Fig. 6I ): (i) a ventrolateral ridge, which originates from the lateral ridge described in the anterior caudal vertebra, which displaced to more ventral position (corresponds here to the ventrolateral edge of the ventral surface and is only connected with the anterior chevron facets); (ii) a lateral longitudinal ridge located at midpoint of the dorsoventral width of the centrum (apparently absent in the first middle caudal vertebrae of Tastavinsaurus sanzi ). This later ridge is placed below an anteroposteriorly elongated ridge that corresponds to the position where the caudal rib was in the anterior caudal vertebrae. The region between this rudimentary caudal rib and the lateral ridge, and between the lateral ridge and the ventrolateral one, is dorsoventrally concave. The ventral surface of the centrum is mediolaterally wide and flat ( Fig. 6L ). The posterior chevron facets are more developed than the anterior ones and preserve a semicircular outline. Several small foramina are visible in the ventral surface as occur in several titanosauriforms ( Mannion et al. 2013). The neural canal is dorsoventrally higher than wide with a semi-oval outline in anterior view, and wider than higher with a quadrangular outline in posterior view. The ventral surface of the neural canal is flat. There is a tuberosity in the posterior half of the centrum dorsal surface connected with the longitudinal ridges that are in the ventral surface of the neural canal near the pedicels, which are also observed in anterior caudal vertebrae.

The anterior neural arch is anteriorly displaced (placed in the anterior half of the centrum) but does not reach the anterior edge of the anterior articular surface of the centrum ( Fig. 6G, I ). This anterior displacement of neural arch in middle caudal vertebrae is characteristic of titanosauriforms ( Salgado et al. 1997) and in the non-neosauropods Cetiosaurus oxoniensis ( Upchurch and Martin 2003) , Moabosaurus utahensis ( Britt et al. 2017) , and Mierasaurus bobyoungi ( Royo-Torres et al. 2017b) . The lateral surface of the pedicels is rugose. The pedicels are transversely compressed. No anteroposteriorly oriented ridge and fossa (‘shoulder’) between the prezygapophyses and the postzygapophyses is present in the anterior-middle caudal vertebrae of Garumbatitan morellensis unlike Andesaurus delgadoi ( Mannion and Calvo 2011) , Lusotitan atalaiensis , and Giraffatitan brancai ( Mannion et al. 2013) , Huabeisaurus allocotus ( D’Emic et al. 2013) , and Sonorasaurus thompsoni ( D’Emic et al. 2016) . The prezygapophyseal processes are transversely compressed and surpass the anterior edge of the anterior articular surface of the centrum. The first middle caudal vertebra seems to be characterized by an anteroventral deflection of the prezygapophyseal processes as occurs in the 16th caudal vertebra of Tastavinsaurus sanzi ( Royo-Torres 2009) . The medial surface of the prezygapophyseal process is flat whereas the lateral one is transversely convex. The prezygapophyseal facets are rudimentary and poorly defined, facing medially. The sprl is single and fades out before reaching the tip of the prezygapophyseal processes and the dorsal end of neural spine. The sprf is restricted to base of the neural spine, which is ventrally delimited by the tprl (posteriorly located to the anterior articular surface of the centrum) ( Fig. 6H, K ). The dorsal half of the anterior surface of the neural spine is completely covered by the rugosities of the prsl (not medially restricted). The postzygapophyseal processes are posteriorly projected from the dorsal edge of the neural spine unlike Tastavinsaurus sanzi ( Royo-Torres 2009) . The spol extends from the dorsal edge of the postzygapophyses up to the distal end of the neural spines, becoming less pronounced in the dorsal half of the spine. The spol borders the spof, which is ventrally deep, and the dorsal two-thirds of the spof are covered by the rugosities of the posl ( Fig. 6J ). The region between the postyzygapophyses is not depressed as in the anterior and middle caudal vertebrae of Tastavinsaurus sanzi ( Royo-Torres 2009) and the last preserved anterior caudal vertebrae of Garumbatitan morellensis (SAV05-060va). No hyposphenic structure seems to be present. The postzygapophyseal facets are reduced and undefined, covered by some rugosities and face laterally. The neural spine is posterodorsally oriented. The anterior surface has a straight profile from the top of the spine up to the tip of the prezygapophyseal processes (this profile is slightly different from the 16th caudal vertebra of Tastavinsaurus sanzi, Royo-Torres 2009 ). The dorsoposterior edge of the spine does not reach the posterior articular surface as in Tastavinsaurus sanzi ( Royo-Torres 2009) . The neural spine is only slightly expanded and has a round dorsal edge. The posterior surface is wider than the anterior one. In lateral view the neural spine is subtriangular in shape, and the anteroposterior width decreases dorsally, against the rectangular profiles of the dorsal end of the neural spine in Tastavinsaurus sanzi , and the anteroposteriorly expanded one of Europatitan eastwoodi ( Torcida Fernández-Baldor et al. 2017) . The anteroposterior width of the neural spine of Soriatitan golmayensis also decreases dorsally, but it has a subvertical neural spine ( Royo-Torres et al. 2017a).

Middle-posterior caudal vertebrae:

Four middle-posterior caudal vertebrae (SAV08-047, SAV08- 048, SAV08-049, and SAV08- 050, Fig. 7 ) were found in partial articulation, 1 m from the distal end of the series of nine middle caudal vertebrae (SAV08-060-061-063-065-067-066- 064-068-069-070-071). Considering the general morphology and the size, we believe that all these specimens belong to the same individual (the series of nine caudal vertebrae still need to be prepared). The centra are amphicoelous, i.e. the anterior and posterior articular surfaces are concave ( Fig. 7C, D, G ), differing from the slightly procoelous caudal vertebrae of Tastavinsaurus sanzi ( Royo-Torres 2009) . No important tuberosities or pits are present in the articular surfaces. The anterior and posterior articular surfaces of the centrum are slightly dorsoventrally compressed, with a straight-to-concave dorsal edge and convex lateral ones. The aEI spans ranges from 1.39 to 1.46. The lateral surface is anteroposteriorly concave, dorsoventrally convex at midpoint, and marked by the lateral ridge (also present in middle caudal vertebrae), but only developed near the anterior and posterior edges of the centrum ( Fig. 7C, D ). Near the posterior edge of the centrum, there is a small depression below this lateral ridge in SAV08-49 ( Fig. 7D ); and near the anterior edge of the centrum and above the lateral ridge there is another depression present in all preserved middle-posterior caudal vertebrae (autapomorphy of Garumbatitan morellensis ). The ventrolateral ridges are rudimentary or absent, and associated with the chevron facets. The ventral surface is transversely convex and, generally, slightly concave between the chevron facets ( Fig. 7A, F ). These facets are semicircular. The neural canal is subcircular.

The anterior neural arch is anteriorly displaced but does not reach the anterior edge of the articular anterior surface of the centrum. The lateral surface of the pedicels is covered by a complex of three anteroposteriorly elongated ridges ( Fig. 7C, D, G ): (i) one ridge located in the position which corresponds to the position of the caudal rib in the anterior caudal vertebrae; (ii) one at midheight of the neural arch pedicel; and (iii) the dorsalmost one extending from the dorsal margin of prezygapophyseal process. The presence of this complex of three ridges is considered herein as autapomorphic of Garumbatitan morellensis , and is absent in other titanosauriforms. The pedicels of the neural arch are transversely compressed. The prezygapophyseal processes are anteriorly projected and surpass the anterior edge of the anterior articular surface of the centrum. The medial and lateral surfaces of these processes are transversely convex and the prezygapophyseal facet is absent. In dorsal view, the prezygapophyseal processes are medially curved (this curvature is not so pronounced in Tastavinsaurus sanzi, Royo-Torres 2009 ). The sprl is single and does not reach the tip of the prezygapophyseal processes. They are developed in the ventral half of the neural spine reaching its dorsal end. The distance that prezygapophyses extend beyond the anterior margin of the centrum is less than 20% of centrum length (excluding ball); which differs from the condition shown by most of somphospondylan titanosauriforms, including Tastavinsaurus sanzi ( Mannion et al. 2013, 2019a, b). The sprf is present along the total height of the neural spines, but shallower in the dorsal half. This fossa is ventrally delimited by the tprl, which is posteriorly located to the anterior articular surface of the centrum. The sprf is covered by the rugosities of the prespinal lamina, which bears a medially constricted ridge ( Fig. 7I ), absent in Tastavinsaurus sanzi ( Royo-Torres 2009) . The spol and spof are absent, and the posterior surface of the neural spine is rough. The neural spine is anteroposteriorly elongated, and the dorsal margin expands anteriorly and posteriorly. The posterior expansion of the neural spine coincides in the posterior projection of the spine and results in a lateral bulge, also considered an autapomorphy of Garumbatitan morellensis . The posterodorsal edge is posteriorly projected, located behind the posterior articular surface of the centrum, condition shared with Venenosaurus dicrocei ( Tidwell et al. 2001) and some non-titanosauriform sauropods such as Camarasaurus ( Osborn and Mook 1921, Gilmore 1925, Ostrom and McIntosh 1966, McIntosh et al. 1996a, 1996b). The dorsal edge is straight-to-smoothly convex in lateral view, sloping posteriorly, unlike the markedly concave dorsal edge of the middleposteriorcaudalvertebraeof Tastavinsaurussanzi ( Royo-Torres et al. 2006), Astrophocaudia slaughteri ( D’Emic 2013) , Aragosaurus ischiaticus (personal observation, P.M. 2014), Cedarosaurus weiskopfae (personal observation, P.M. 2018), and slightly developed in some caudal vertebrae of Giraffatitan brancai ( Janensch 1950) .

Chevrons:

Four anterior chevrons are available for study (from the anteriormost preserved chevron to the posteriormost one: SAV05-060chb, SAV05-063; SAV05-060cha, and SAV05-060chc; Fig. 8 ), which probably belong to the first half of the tail. In addition, two other chevrons were identified within the jacket SAV08-060-061-063-065-067-066-064-068- 069-070-071. Based on a relatively complete series of chevrons (e.g. Janensch 1950, Royo-Torres 2009, D’Emic et al. 2013), the preserved chevrons are interpreted as the third to the sixth. The proximal end of the dorsal rami is badly preserved in the some of the chevrons (e.g. right ramus of SAV05-063 and SAV05- 060cha is absent; and left and right ones are broken in SAV05- 060chc). The haemal canal is more than 40% of the total height of the chevron (around 40–44%) ( Fig. 8B, G, L, Q ), which is common in titanosauriforms such as Lusotitan atalaiensis , Europatitan eastwoodi , Soriatitan golmayensis , and Tastavinsaurus sanzi ( Royo-Torres 2009, Mocho et al. 2017a, Royo-Torres et al. 2017a, Torcida Fernández-Baldor et al. 2017). The dorsal rami are transversely compressed with an anteroposteriorly convex lateral surface, and an anteroposteriorly flat medial one. The anteromedial edge of the dorsal rami is acute, resulting in a proximodistal crest, which converge, ventrally to the anterior crest of the distal end of the chevron. The posterior edge of the dorsal rami is rounded. The articular facets for the vertebrae are badly preserved, but some information can be obtained. These facets are more transversely expanded than anteroposteriorly, and the lateral edge is laterally projected (some rugosities are present laterally, below the articular facets). A posterior rugosity is present right below these facets. The proximal end is interpreted as open, i.e. the chevrons are not dorsally bridged.

The distal end is transversely compressed being anteroposteriorly longer than mediolaterally(the transverse compression becomes more significant towards the posteriormost preserved element, SAV05-060chc). The distal end is posteriorly deflected ( Fig. 8C, H, M, R ). The anterior and posterior edges are acute, resulting in anterior and posterior crests. The anterior crest preserves a step ( Fig. 8O, H ) that is absent in the more anterior chevrons of Tastavinsaurus sanzi [a step appears from the seventh chevron, at a more distal position ( Royo-Torres 2009) than the anterior step observed in Garumbatitan morellensis )] and of Europatitan eastwoodi ( Torcida Fernández-Baldor et al. 2017) . The posterior edge is convex to straight in lateral view (no step is present as in Europatitan eastwoodi, Torcida Fernández-Baldor et al. 2017 ). Above this anterior crest and below the end of the haemal canal there is a triangular depression that persists in the preserved series of chevrons. Similarly, in the posterior surface of the distal end, there is a subtriangular depression below the end of the haemal canal, but only in the first preserved chevron. The lateral surface of the distal end is striated, and no bulge is observed.

Interclavicle:

SAV05-055 shares a similar morphology to elements that have been interpreted as interclavicles such as NMB-1698- R from Spinophorosaurus nigerensis [see also: ( Tschopp and Mateus 2013)]. The proximal end of an interclavicle was found near the holotype specimen (SAV05-055, Fig. 9 ). The shaft of this interclavicle is anteroposteriorly compressed, with a transversely convex anterior surface and flat posterior one ( Fig. 9A ). The proximal end becomes mediolaterally compressed, and the surface is striated. It is possible to identify a facet in the left side of the proximal end (the right face is not well individualized) for the contact with coracoids (following: Tschopp and Mateus 2013) ( Fig. 9D ). The proximal tip of the interclavicle is pointed and not bifurcated.

Pubes:

The distal end of two pubes are described (right pubis, SAV05- 031a; left pubis, SAV05-31b; Fig. 10 ). Besides the difference in robustness between these two pubes (SAV05-031a and SAV05- 31b), they are referred as belonging the same individual, in this case, to the paratype specimen, being recovered below its left femur. The pubic shaft is transversely compressed and slightly lateromedially and anteroposteriorly expanded in its distal end [differing from a planar distal blade common in several titanosaurs, Poropat et al. (2016)]. The anterodistal edge is not projected, as in Europatitan eastwoodi ( Torcida Fernández-Baldor et al. 2017) ; in this regard, it differs from the hook-shaped profile present in the camarasaurid Lourinhasaurus alenquerensis (Mocho et al. 2014) , and the titanosaurforms Giraffatitan brancai ( Janensch 1961) and Tastavinsaurus sanzi ( Canudo et al. 2008, Royo-Torres 2009, Royo-Torres et al. 2012). A medial triangular facet is present near the distal end, which is considered to be part of the symphysis. The distal surface is rough and concave transversely. No crests and tuberosities are observed on the lateral and medial surface of the preserved portion.

Femora:

Four femora have been identified, two from the holotype specimen (left, SAV05-023; right, SAV05-024; Fig. 11 ) and two from the paratype specimen (left, SAV05-031; and right, SAV05-013; Fig. 12 ). The most complete femur of the holotype specimen is the right one, which lacks a sector of the proximal end. Considering the two other remains from the proximal half, which are still unprepared (including the femora head), we tentatively estimate a proximodistal length of around 1.9–2.0 m. Only the distal end of the left femur was recovered. In the paratype, the left femur is complete but presents some deformation and the right femur lacks the proximal half. The femur is straight in lateral and anterior views and has an important medial deflection of the proximal one-third ( Fig. 12B, D ). The femoral proximolateral margin is medial to the lateral margin of the distal half of the shaft as in other macronarians ( Royo-Torres et al. 2012, Mannion et al. 2013) but differing from Tastavinsaurus sanzi , which lacks a strong medial deflection. This results in a well-developed lateral bulge, representing 44% of the narrowest transverse width of the femoral shaft (following Salgado et al. 1997), which might have been affected by some deformation. Considering the whole femoral morphology, particularly the distolateral projection of the distal end of the trochanteric shelf, which is not expected to be affected by the anteroposterior deformation of the femur, we consider plausible the presence of one of the most developed lateral bulges in sauropods, which would be characteristic of Garumbatitan morellensis . The diaphyses of these femora are markedly anteroposteriorly compressed. The mediolateral width of the diaphysis is around 3.23 times the anteroposterior width in the holotype, and 2.67–2.99 times in the paratype specimen, which is markedly higher than in other titanosauriforms from the Early Cretaceous of Iberia [ Tastavinsaurus sanzi is 1.67–1.5 times, Royo-Torres (2009); Soriatitan golmayensis is 2.18, Royo-Torres et al. (2017a)]. These values are possibly slightly affected by some crushing, but we believe that it is not to significant. The cross-section of the diaphysis is elliptical, slightly anteroposteriorly wide in the lateral half. In the posterior surface, a broad trochanteric shelf emerges from the reduced greater trochanter that fades away at level of bulge apex ( Fig. 12D ). The trochanteric shelf has a prominent proximomedial-to-distolateral orientation, which is considered as autapomorphic. The fourth trochanter is located at the posteromedial border of the shaft, is dorsoventrally elongated ridge, and its distal tip is placed above femur midheight. It is associated with a medial and proximodistally elongated depression ( Fig. 12E ). In the paratype, the fourth trochanter is medially projected, being observed in anterior view ( Fig. 12B ). This feature was recovered as synapomorphy of Brachiosauridae ( Mannion et al. 2013) and is absent in Tastavinsaurus sanzi ( Royo-Torres 2009) . However, this medial projection of the fourth trochanter can be a consequence of deformation, and the full preparation of the femur of the holotype might provide some insights about the orientation of the fourth trochanter. The femoral anterior surface bears a longitudinal crest, distally and proximally marked ( Figs 11A , 12B, H ). This crest is interpreted as the linea intermuscularis cranialis present in some lithostrotians ( Otero 2010, D’Emic 2012) and in the non-lithostrotian titanosaur Diamantinasaurus matildae ( Poropat et al. 2015, 2023). The femoral head is elliptical in proximal view, anteroposteriorly compressed, probably accentuated due the deformation. The femoral head is dorsomedially projected, and the proximal surface is rough and convex. There is a step below the femoral head, absent in Tastavinsaurus sanzi ( Canudo et al. 2008, Royo-Torres 2009). The region between the lateral bulge and greater trochanter is anteriorposterioly compressed, and the bulge is anterolaterally deflected. The anterior and posterior surfaces of the lateral bulge are striated.

The distal end of the femur is smoothly concave anteriorly and posteriorly. The tibial condyle is longer anteroposterioly than the fibular one, and both bear rough and convex surfaces ( Figs 11H , 12F, G ). The medial surface of the tibial condyle is flat as in other sauropods such as Lourinhasaurus alenquerensis (Mocho et al. 2014) and Giraffatitan brancai ( Janensch 1961) . In distal view, the condyles are anteroposteriorly oriented. The distal end is perpendicular and slightly laterally bevelled (less than 10° from the horizontal), differing from the laterally bevelled distal end of Cedarosaurus weiskopfae , Tastavinsaurus sanzi , Soriatitan golmayensis , Phuwiangosaurus sirindhornae , ‘ Paluxysaurus jonesi ’ [considered as Sauroposeidon proteles by D’Emic and Foreman (2012)], and Vouivria damparensis among others (e.g. Mannion et al. 2013, 2017, 2019a, b, Royo-Torres et al. 2017a). The anterior expansion of the distal condyles is not significant unlike some lithostrotians ( Wilson 2002, Mannion et al. 2013, 2019a, b). The tibial to fibular condylar anteroposterior length ratio is less than 1.2 as in Soriatitan golmayensis ( Royo-Torres et al. 2017a; Mannion et al. 2019b), differing from the condition, which seems to characterize the Somphospondyli clade [1.2 or greater ( Mannion et al. 2013) based on the LSDM matrix), including Tastavinsaurus sanzi . The ratio of mediolateral breadth of tibial condyle to breadth of fibular condyle is less than 0.8 (0.69–0.79), as occur in the brachiosaurids Brachiosaurus altithorax and Giraffatitan brancai and Vouivria damparensis , and in many somphospondylans ( Wilson 2002, Poropat et al. 2016). This ratio is greater than 0.8 in Tastavinsaurus sanzi and Soriatitan golmayensis ( Royo-Torres 2009, Poropat et al. 2016, Mannion et al. 2017, 2019a, b, Royo-Torres et al. 2017a). The epicondyle is laterally projected, well developed, and separated from fibular condyle by a longitudinal groove (more developed in the largest individual and referred to here as the posterolateral fossa; Figs 11D, G , 12D, F–H ). This epicondyle is developed up to the distal margin of the femur, being visible and individualized from the fibular condyle in distal view. The intercondylar region is anteroposteriorly compressed in both femora and, in anterior view, it is possible to observe a marked local concavity between the condyles in smallest individual, but unpronounced in the largest one. Small intercondylar ridges are present in the holotype specimen ( Fig. 11F ), as occur in Vouivria dampariensis ( Mannion et al. 2017) .

Tibiae:

In the Sant Antoni de la Vespa fossil site, four tibiae were found: two from the holotype specimen (right, SAV05-065, Fig. 13A ; left, SAV05-025, not prepared), and two from the paratype one (left, SAV05-036, Fig. 14G–L ; and right, SAV05-032, Fig. 14A– F , the most proximal section of the cnemial crest is fractured). The left tibia has a pronounced mediolateral compression and torsion between proximal and distal ends, and, in consequence, the morphological description will be mainly focused on the elements from the right side. The tibia is straight in anterior and lateral views (not arched as in Lusotitan atalaiensis, Mocho et al. 2017a ). The proximal section is D-shaped with a straight lateral edge (corresponding to the fibular articular facet) and a concave to straight posterior edge ( Figs 13A , 14C ). In the proximal surface of the right tibia of the paratype (SAV05-032), the perpendicular width to articular fibular facet (approximately the mediolateral width of the proximal end) has a similar width to its perpendicular (approximately the anteroposterior width of the proximal end). However, this mediolateral axis is slightly longer in the right tibia of the holotype (SAV05-065), i.e. in the less deformed elements, the proximal end is slightly anteroposteriorly compressed. In the case of the left tibia of the paratype, the proximal section has a mediolaterally compressed outline owing to deformation ( Fig. 14I ), but the axis perpendicular to the fibular articular facet is still the longest one, which possibly acquired a different orientation because of the torsion of the proximal end. The proximal surface is rough and flat with a circular depression in the medial two-thirds of the surface. The region near the articular facet of the fibula extends slightly distally. The lateral surface of the proximal section is smoothly concave bearing a subtriangular fibular articular facet. This surface is anteriorly bordered by the cnemial crest and posteriorly by a lateral crest rising from the proximal surface ( Fig. 14D, E ). The cnemial crest is round [ Fig. 13B ; unlike the triangular cnemial crest of Tastavinsaurus sanzi ( Royo-Torres 2009) , Europasaurus holgeri ( Carballido et al. 2020) and Lusotitan atalaiensis ( Mocho et al. 2017a) ], asymmetrical (the ventral edge is longer) and laterally directed in the non-deformed elements. A laterally projected cnemial crest ( Figs 13A , 14C ) is common in sauropods ( Wilson and Sereno 1998, Wilson 2002, Mannion et al. 2013), but it is anterolaterally projected in several titanosauriforms such as Tastavinsaurus sanzi ( Royo-Torres 2009) . In the holotype specimen of Garumbatitan morellensis , the cnemial crest expands becoming thicker proximally. The posterior surface of the cnemial crestpreservessomerugosities, butthe‘tuberculumfibularis’present in Giraffatitan brancai and Vouivria dampariensis ( Mannion et al. 2017) , in many diplodocids ( Harris 2007, Tschopp et al. 2015), and in Janenschia robusta ( Mannion et al. 2019b) , is absent. From the proximal surface extends a proximodistal ridge, posterior to the cnemial crest ( Fig. 14C ) interpreted as a ‘second cnemial crest’ (sensu Bonaparte et al. 2000;; Mannion et al. 2013). This crest is present in many eusauropods but absent in several somphospondylans and diplodocoids ( Mannion et al. 2013, 2017, 2019a, b). The anteromedial surface of the proximal end is smoothly concave in the holotype specimen.

The tibial shaft bears a sub-elliptical to D-shaped cross-section, with a flat posterolateral surface. The lateral edge of the shaft is acute, resulting in a crest structure. The distal section bears a transverse expansion (not so pronounced in the left tibia of the paratype specimen owing to deformation; Figs 13B , 14A, F ) and the distal end mediolateral width to the long axis of the cross-section horizontally through the midshaft ratio ranges from 1.56 to 2.0 (excluding the most deformed tibia, SAV05- 036). The mediolateral width: the anteroposterior width ratio of the distal end ranges from 1.75 to 1.62. The anterior surface of the distal end is flat-to-slightly concave, and the anteromedial edge bears a rough proximal ridge in the paratype specimen, particularly thicker in the holotype one. The articular surface for the ascending process is transversely elongated and laterally projected, with a flat surface, occupying a more dorsal position than posteroventral process, but relatively lower when compared with other macronarians such as Lusotitan atalaiensis ( Mannion et al. 2013, Mocho et al. 2017a), Lourinhasaurus alenquerensis (Mocho et al. 2014) , or Giraffatitan brancai ( Janensch 1961) . The posteroventral process is oval and smaller than the articular surface for the ascending process and bears a convex and rough surface. The articular surface for the ascending process and the posteroventral process are separated posteriorly by a not well-marked longitudinal concavity. The tibia is 64% of femur length based on the paratype specimen (the femur is not complete in the holotype one), against 55% in Tastavinsaurus sanzi ( Canudo et al. 2008, Royo-Torres et al. 2012). Similar values are observed in Cedarosaurus weiskopfae (63%), Euhelopus zdanskyi (63%), and Phuwiangosaurus sirindhornae (62%) ( Poropat et al. 2016).

Fibulae:

Four fibulae were found and referred to Garumbatitan morellensis , two from the holotype (right, SAV05-064, Fig. 13 ; left, SAV05-026, not prepared) and two from the paratype (right, SAV05-033, Fig. 15A–F ; left, SAV05-037, Fig. 15G–L ). The description is mainly based on the right elements of the paratype and holotype specimens (the left one from the holotype still needs to be prepared, and the left one from the paratype has an important mediolateral deformation, as occurs with the left tibia). The fibula is straight in anterior and lateral view ( Figs 13E , 15A, G ) lacking a pronounced sigmoid profile as many somphospondylans such as Oceanotitan dantasi ( Mocho et al. 2019a) , ‘ Paluxysaurus jonesi ’ ( Rose 2007) , Huabeisaurus allocotus ( D’Emic et al. 2013) , Phuwiangosaurus sirindhornae ( Martin et al. 1999) , and Tastavinsaurus sanzi ( Royo-Torres 2009) . The presence of a sigmoidal fibula was recovered as synapomorphy of Somphospondyli/Titanosauria ( Mannion et al. 2013; based on the LCDM matrix). The proximal one-third of the fibula is anteroposteriorly expanded, more posteriorly than anteriorly. In medial view, there is a short triangular tibial articulation surface (occupying one-fifth of the fibular total length), differing from the long tibial scars present in basally branching macronarians (e.g. Ostrom and McIntosh 1966, Mocho et al. 2014) and Oceanotitan dantasi ( Mocho et al. 2019a) . This surface faces medially-to-slightly proximomedially. The ventral apex of the tibia articular surface is located in the anteromedial edge of the shaft, and coincides with the presence of a boss structure, more pronounced in the left fibula, interpreted as the anterior trochanter of Wilson and Sereno (1998), which is absent to rudimentary in other titanosauriforms, such as Lusotitan atalaiensis ( Mocho et al. 2017a) , Tastavinsaurus sanzi ( Royo-Torres 2009, Royo-Torres et al. 2012), and Giraffatitan brancai ( Janensch 1961) . The anteromedial crest departs from this anterior trochanter to the proximal surface and occupies one-fifth of the fibular total length (as the tibial articular surface; Fig. 14C, D, I, J ). The anteromedial crest is visible in proximal view being embraced by the cnemial crest of the tibia. The presence of an anteromedially directed crest extending into a notch behind the cnemial crest of the tibia was recovered as a synapomorphy of the somphospondylan clade Sauroposeidon + ( Tastavinsaurus + (E uhelopodidae + ( Chubutisaurus + Titanosauria))) by D’Emic (2012) and Somphospondyli/Titanosauria by Mannion et al. (2013; based on the LCDM matrix). This crest is transversely constricted and bears a longitudinal sulcus on its lateral face. The medial face of the fibular diaphysis is concave transversely along its length, resulting in a D-shaped cross-section with a concave medial border, being bordered by two ridges, which corresponds to the anteromedial and posteromedial edges of the diaphysis, which is here considered as autapomorphic of Garumbatitan morellensis [in Tastavinsaurus sanzi , only the proximal half is transversely concave medially, Royo-Torres et al. (2006)]. Fibular diaphysis with a transversely concave medial face can be observed in some titanosaurs, such as Lohuecotitan pandafilandi ( Díez Díaz et al. 2016) . The lateral trochanter is a complex structure comprising an oval and shallow tuberosity inserted in a flat area bordered by two proximodistal ridges (the posterior one is more pronounced and located near the posterior face of the diaphysis; Figs 13E , 14A, G ), as occurs in several somphospondylans ( Upchurch 1998, Mannion et al. 2013, 2017), but also present in the brachiosaurid Giraffatitan brancai ( Mannion et al. 2013) . The lateral trochanter is only slightly laterally pronounced, differing from the lateral projected lateral trochanters common in some somphospondylans (e.g. Ksepka and Norell 2006, Salgado and Carvalho 2008, Otero 2010, Díez Díaz et al. 2013b, Lacovara et al. 2014). The tip of the lateral muscle scar is located approximately at midshaft.

The proximal edge of the fibula is straight and horizontal in lateral view. The proximal surface is rough and flat with a subrectangular outline ( Figs 13A , 14C, I ), different from the autapomorphic crescentic morphology of Tastavinsaurus sanzi ( Royo-Torres et al. 2012) . Distally, the anteromedial ridge of the diaphysis has a round projection. The lateral face of the distal end is transversely convex, partially related with the lateral projection of the distal end. The medial edge of the distal section is projected, forming a medial lip which articulates with the astragalus. The distal surface is rough and flat-to-concave and has a semicircular-to-oval outline as in several other sauropods ( Royo-Torres 2009), with a flat medial edge and round lateral one (the lateral margin of the distal surface extends to the diaphysis of the fibula). This morphology is markedly distinct from the autapomorphic quadrangular morphology of the fibular distal end shown by Tastavinsaurus sanzi ( Canudo et al. 2008, Royo-Torres 2009, Royo-Torres et al. 2012). Excluding the left fibula of the paratype, which is deformed: (i) the mediolateral width to the anteroposterior width ratio of the distal end is greater than 0.8; and (ii) the mediolateral width of distal end to the mediolateral width at the midshaft ratio is greater than 2.0, differing from Tastavinsaurus sanzi , which is characterized by a ratio lower than 2.0 ( Royo-Torres et al. 2012).

Tarsus:

Two complete astragali have been described: one right astragalus from the holotype (SAV05-066, articulated with the fibula and tibia, Fig. 13 ) and other right one from the paratype (SAV05-034, Fig. 16 ). The astragalus is wedge-shaped, and in proximal view it becomes anteroposteriorly narrow in its medial half ( Fig. 16B ), characteristic of neosauropods ( Wilson 2002). Also in proximal view, the anterior edge is straight and transversely oriented. The posterior edge of the astragalus is straight and transversely oriented behind the ascending process, but the medial sector of the posterior edge is mainly straight and posterolaterally-anteromedially oriented, culminating in the round and blunt medial apex of the astragalus ( Fig. 16B ). In anterior view, the apex of the astragalus is proximodistally constricted ( Fig. 16E ) as occurs in derived eusauropods ( Upchurch 1995, 1998, Mannion et al. 2017). The ascending process almost reaches the posterior margin of astragalus (when the dorsal surface of the ascending process is in horizontal; Fig. 16C, F ), a condition commonly shared by the members of Neosauropoda ( Wilson and Sereno 1998, Wilson 2002). The proximal surface of this process is rough and flat. The posterior surface of the ascending process is smoothly concave in the holotype (this surface seems to be eroded) and flat in the paratype (with a small foramen). From the proximomedial corner of the dorsal surface of the ascending process, a rudimentary proximodistal ridge is present that does not reach the posterior edge of the astragalus ( Fig. 16D ). In this sector a well-developed crest can be observed in several non-somphospondylan titansoauriforms, such as Lusotitan atalaiensis ( Mannion et al. 2013, Mocho et al. 2017a) and Giraffatitan brancai ( Janensch 1961) , being considered as absent in Garumbatitan morellensis . The posterior margin of the astragalus lacks a tongue-like projection posteromedial to the ascending process ( Fig. 16D ), as occurs in titanosauriforms ( Mannion et al. 2013). Medial to this rudimentary crest there is a foramen. The proximal surface of the tibial articular surface is broadly concave and smooth, slopping posteriorly. The mediolateral width to maximum proximodistal height ratio is greater than 1.8 [1.84–1.87; it is less than 1.8 in Tastavinsaurus sanzi ( Royo-Torres et al. 2012) ]; and the mediolateral width to the maximum anteroposterior length ratio is 1.87–1.94. The rough ventral surface of the astragalus is transversely convex and transits continuously to the also rough anterior surface. The articular surface for the fibula (lateral surface of the astragalus) faces laterally, is well-limited, and occupies the entire lateral surface of the astragalus. This articular surface contains two foramina separated by a ridge (this part of the astragalus is covered by sediment in the holotype specimen). The astragalus caps most of the distal end of the tibia, as in the brachiosaurid Vouivria dampariensis ( Mannion et al. 2017) , but is distinct from the reduced astragalus that characterizes most titanosauriforms ( Ksepka and Norell 2006, Wilson and Upchurch 2009), including Tastavinsaurus sanzi ( Royo-Torres et al. 2012) . No calcaneum was identified, the absence of this element being considered as a reliable feature of this taxon, which is present in most non-titanosaurian sauropopods (e.g. Poropat et al. 2023), as in Tastavinsaurus sanzi ( Canudo et al. 2008, Royo-Torres 2009, Royo-Torres et al. 2012) and Gobititan shenzhouensis ( You et al. 2003) . The preservation of the calcaneum is unusual; however, we believe that the absence of this element in Garumbatitan morellensis is plausible. This is supported by the fact that two nearly complete hindlimbs, including their pedes, were found in close association, and preserve almost all their distal elements (i.e. phalanges).

Pedes:

A partially articulated to associated right pes (SAV05-068) was found for the holotype specimen ( Figs 17A , 18 , 20 , 22 ). Some elements of the left pes (SAV05-021 and SAV05-024) of the holotype were also recovered. An almost complete right pes (SAV05-35) and a left metatarsal III ( SAV05-038 .a) was found associated and partially articulated to the smallest individual, which corresponds to the paratype specimen ( Figs 17B , 19 , 21 , 23 ). Another three left metatarsals, here considered as referred materials, were found associated with these two legs (SAV05- 044, SAV05-056, and SAV05-058). The presence of two left metatarsals III, with similar morphology and size, indicates the presence of at least two individuals with similar size (including the paratype specimen) in addition to the holotype specimen.

All five metatarsals are preserved in the holotype and paratype specimens, and when articulated, they bear a slightly arched profile with convexity facing dorsally. The shortness and robustness of metatarsals I and V relative to metatarsals II, III, and IV is considered here as autapomorphic of Garumbatitan morellensis . Three metatarsals I are preserved [the right of the holotype specimen (SAV05-068.a, Fig. 18A–F ), which is mediolaterally deformed; the right one of the paratype (SAV05-35.a, Fig. 19A–F ); and a referred left one (SAV05-044)]. Metatarsal I ( Figs 17 , 18 ) is three-quarters the length of metatarsal II, expands proximally and distally, and is the most robust metatarsal. The proximal surface is subtrapezoidal to subtriangular, rough, flat, and sloping medially. In proximal view, the medial edge is straight-to-slightly convex and the lateral one is concave for the reception of metatarsal II ( Figs 18E , 19E ). The ventrolateral edge of the proximal surface deflects distally extending to the ventrolateral edge of metatarsal I (with a ridge like-morphology, i.e. the ventrolateral crest; Fig. 19C ). The dorsolateral edge of the proximal face is proximally projected ( Fig. 18B ). The proximal surface is angled ventromedially approximately 15° relative to the axis of shaft ( Figs 18A , 19A ). The diaphysis of metatarsal I is elliptical in cross-section in the holotype (probably a consequence of deformation) and triradiate in the paratype (with three main surfaces, the continuous dorsomedial, lateral, and ventral surface). In the proximal half, the dorsomedial surface is continuous and, medially, it curves posteriorly where it meets with the ventral one, resulting in the ventromedial crest/ ridge (which is present along its total proximodistal width of the metatarsal). In the proximal half of the ventromedial crest, there is a pronounced elliptical tuberosity ( Figs 18A , 19B ), not described in Tastavinsaurus sanzi ( Royo-Torres 2009) . The presence of this tuberosity in the medial face of the metatarsal I, seems to be unique for the brachiosaurids Giraffatitan brancai , Sonorasaurus thompsoni , and Venenosaurus dicrocei ( D’Emic et al. 2016, Mannion et al. 2019b). In the distal half of the metatarsal, the dorsomedial surface is subdivided in dorsal and medial surfaces, separated by a short proximodistal crest coming from the medial distal condyle. The distal half of the dorsal surface is flat (holotype) or slightly concave (paratype) between the distal condyles. The lateral surface is bordered by a proximodistally elongated ventrolateral and dorsolateral crests. The proximal half of the lateral surface is deeply concave and striated becoming flat distally, with a proximodistally elongated tuberosity (ridge-like in the holotype specimen). No ventrolateral projection in the distal end is present [this projection in common in diplodocids ( Tschopp et al. 2015) and in other taxa such as Ligabuesaurus leanzai ( Bonaparte et al. 2006) and Gobititan shenzhouensis ( You et al. 2003) ]. The distal condyles are well-marked, they are convex transversely and dorsoventrally, and are separated by a ventral intercondylar concavity (excavated in the paratype specimen). The lateral and medial condyles are located at a perpendicular plan relative to the axis of the diaphysis. In distal view, the condyles diverge ventrally, and the medial condyle is dorsoventrally elongated. The metatarsal I to metatarsal V proximodistal length ratio is 1.05, differing from some titanosauriforms, which are a characterized by a ratio less than 1.0 as Tastavinsaurus sanzi , Cedarosaurus weiskopfae , Sonorasaurus thompsoni , Gobititan shenzhouensis , and Ligabuesaurus leanzai ( Mannion et al. 2013) .

Three metatarsals II were recovered [the right (SAV05-068.b, Fig. 18G–L ) and left (SAV05-021) from the holotype specimen; and the right one (SAV05-035.b, Fig. 19G–L ) from the paratype specimen]. They have a subrectangular proximal surface ( Fig. 18K ). In proximal view, the dorsal and ventral edges are straight (the dorsal and ventral edges have similar mediolateral widths), and the medial and lateral ones are convex and concave, respectively. The proximal surface slopes distomedially. This surface is rough and there are two ‘condyle’-shaped convex structures in the paratype specimen, dorsally and ventrally located, separated by a wide and smooth groove (this structure in condyles is not individualized in the holotype specimen). The dorsolateral apex of the proximal surface is proximally projected as in metatarsal I. The proximal surface extends to the diaphysis of the metatarsal from the dorsolateral and dorsomedial edges. From the dorsolateral edge of the proximal surface emerges the dorsolateral crest of the diaphysis, which reaches the distal condyle (connecting with the ridge that departs from the lateral distal condyle). The diaphysis is D-shaped in cross-section at midlength. The dorsal surface is transversely concave in the dorsal two-thirds and, distally, becomes flat (concave in the paratype specimen) between the proximodistal crests that departs from the lateral and medial distal condyles. In the paratype specimens, in this concave area, there is a small foramen ( Fig. 19G ). The dorsal surface transits continuously to the medial surface in the dorsal two-thirds of the diaphysis and it is separated by the proximodistal crest that comes from the medial distal condyle. The medial surface is transversely flat to transversely convex (with a shallow proximodistal groove in the paratype specimen). The medial surface of the distal condyle is smoothly concave. The ventral surface of metatarsal II is bordered laterally by the ventrolateral crest that connect the ventrolateral edges of proximal and distal surfaces (in the paratype this crest is interrupted at midlenght, and the proximal portion extends to the lateral surface of the diaphysis). The proximal tip of this ventrolateral crest (laterally displaced) is laterally deflected and projected ( Figs 18I , 19I ), which is considered as a possible autapomorphy of Garumbatitan morellensis . From the ventromedial edge of the proximal end departs a proximodistal crest only present in the dorsal one-third of the diaphysis (the transition between the ventral and medial surfaces of the diaphysis in the ventral two-thirds is continuous). The proximal half of the ventral surface is transversely concave and striated. The lateral surface is transversely concave and striated in the proximal half (for the reception of the metatarsal III) and flat in the distal half (marked by the proximodistal crest that extends from the lateral distal condyle in the paratype). In distal view, the distal condyles are dorsoventrally elongated, and the lateral one, is bevelled more than 20° from the sagittal plane of the metatarsal. The condyles are transversely and dorsoventrally convex and separated by an intercondylar groove ventrally marked (especially marked on the right metatarsal II of the holotype) ( Figs 18L , 19L ). The distal end does not have the ventrolateral projection present in diplodocids ( Tschopp et al. 2015).

The metatarsals III and IV are slender and higher than metatarsals I and II, and the minimum transverse diameter of metatarsal III relative to the transverse diameter of the metatarsal I, and the minimum transverse diameter of metatarsal IV relative to the transverse diameter of the metatarsal I are both less than 65%. Four metatarsals III were recovered from the Sant Antoni de la Vespa fossil site [one right (SAV05-068.c, Fig. 18M–R ) from the holotype; the right (SAV05-035.c, Fig. 19M–R ) and the left (SAV05-038.a) from paratype specimen; and a referred left one (SAV05-056)]. The length of metatarsal III is 27–24% of the tibial length, unlike Tastavinsaurus sanzi , with 30% ( Royo-Torres et al. 2012). Similar values are shown by the brachiosaurids Vouivria dampariensis (26%) and Sonorasaurus thompsoni (27%) ( Mannion et al. 2013). The proximal surface is rough, flat, and has a teardrop shape (in SAV05-038.a and SAV05-056, this teardrop shape is lateromedially compressed due to deformation) in proximal view with a convex and concave medial and lateral edge, respectively, and a straight dorsal edge (ventral edge is constricted and mediolaterally shorter than the dorsal one) ( Figs 18Q , 19Q ). The proximal surface becomes transversely shorter dorsolaterally, and the dorsolateral edge curves distally, extending to the dorsolateral crest of the diaphysis. The dorsal surface of the diaphysis is bordered by the dorsolateral and the dorsomedial crests, connecting the dorsolateral and the dorsomedial edges of the proximal end to the distal end. The dorsal surface is flat and becomes concave proximally and distally (between the distal condyles), bearing two small foramina ( Fig. 19M ). Near the distal end, the dorsal surface of the dorsolateral and dorsomedial crests of the diaphysis preserve two pronounced bosses absent in the largest specimen. The lateral and medial surfaces of the metatarsal III are flat, but the lateral one becomes transversely concave in the proximal (striated surface) and distal end (with a small foramen in SAV05-035.c), The lateral and medial surfaces converge in the sagittal plane of the metatarsal III resulting in a constricted ventral face, corresponding to the ventrolateral crest of the diaphysis. The ventrolateral crest expands proximally, resulting in a flat platform, well-developed in the holotype specimen. The distal condyles are individualized and are convex transversely and dorsoventrally (the medial one is longer dorsoventrally than the lateral one), separated by a wide intercondylar groove that slightly progresses to the ventral surface ( Figs 18R , 19R ). The ratio of metatarsal III to metatarsal I proximodistal length is 1.34–1.37 and the ratio of metatarsal III to metatarsal IV proximodistal length is 1.06–1.07.

Four metatarsals IV were recovered in the Sant Antoni de la Vespa fossil site [the right (SAV05-068.d, Fig. 18S–X ) and the left one (SAV05-042) from the holotype; the right one (SAV05- 035.d, Fig. 19S–X ) from paratype specimen; and a referred left one (SAV05-058)]. The metatarsal IV is the slenderest metatarsal. The proximal surface is quadrangular to subtrapezoidal ( Fig. 19W ), rough, and concave in the middle (as occurs in metatarsal II), near the medial edge. The medial and lateral edges are concave. The presence of a concave medial surface in the proximal end of the metatarsal IV ( Figs 18W , 19W ) characterizes many titanosauriforms ( D’Emic et al. 2011, D’Emic 2012, Mannion et al. 2013, 2019b). The ventral edge of the proximal surface is shorter than the dorsal one. The dorsal edge of the proximal surface is straight, and in the holotype specimen, the proximoventral sector of the metatarsal is broken and displaced. The dorsolateral edge of the proximal surface deflects distally. The dorsal surface of diaphysis is transversely convex and becomes flat proximally and distally, between the distal condyles (there is a small foramen in this sector of the metatarsal). The dorsal face is bordered by a dorsolateral and dorsomedial crests only marked near the proximal and distal end. The medial face of the metatarsal is flat along its length, and proximally is marked by two proximodistal ridges: (i) a ventralmost ridge that corresponds to the ventromedial crest of the diaphysis (not associated with the ventrolateral crest of the diaphysis), which is not fully developed in the paratype specimen ( Figs 18T , 19T ); and (ii) a dorsalmost ridge that is proximodistally shorter and located near the ventromedial crest of the diaphysis ( Fig. 19T ), corresponding to prominent rugosities in the holotype specimen. The lateral surface is concave in the proximal end (this concavity extends to the distal half in the paratype specimen) and flat in the distal end. The lateral surface of the diaphysis faces ventrolaterally and converge with the medial surface ventrally resulting in a constricted ventral surface (=ventrolateral crest), as in the metatarsal III. This ventral ridge is double in the holotype specimen. The medial surface of the medial condyle has a small foramen in the holotype specimen. The distal condyles are individualized, with an intercondylar groove that slightly extends to the ventral surface of the metatarsal. The distal condyles are slightly dorsoventrally longer in the paratype specimen, and subcircular in the holotype specimen. The distal surface is perpendicular to the long axis of bone, differing from the medially bevelled distal end present in brachiosaurids ( Mannion et al. 2013, D’Emic et al. 2016)

Two metatarsals V were found [a right one (SAV05-068.e, Fig. 18Y –AC) from the holotype; and a right one (SAV05-035.e, Fig. 19Y –AD) from the paratype specimen]. The metatarsal V has approximately 72% and 77% of the length of metatarsals III and IV, respectively, and is lateromedially compressed. The proximal surface (not preserved in holotype specimen) has an elliptical outline (the medial edge is straight and lateral one is convex), compressed lateromedially, and slopes laterally. The proximal and distal ends of metatarsal V expand dorsoventrally, with a marked proximal expansion (almost two times of the distal dorsoventral expansion), but not as marked as in Tastavinsaurus sanzi ( Canudo et al. 2008, Royo-Torres 2009). The medial surface of metatarsal V is flat, and a marked crest extends from a boss-shaped structure near the distal face. The boss is much more pronounced in the holotype specimen and the ridge seems to be absent. The presence of a pronounced tuberosity near the ventromedial edge of the distal end of the metatarsal V ( Figs 18Z , 19Z ), is considered as an autapomorphy of Garumbatitan morellensis . The lateral surface of the diaphysis is dorsoventrally convex. The distal surface is rough, convex, and has a subcircular outline. The proximal end to the distal end maximum mediolateral width ratio is 1.67, differing from the greater ratio shown by Tastavinsaurus sanzi (2.32; Royo-Torres et al. 2012).

The possible phalangeal (including unguals) formula based on the holotype and paratype specimens is 2-3-3-3-0. The presence of three phalanges in pedal digit IV seems to be unique among eusauropods and only shared with Cedarosaurus weiskopfae ( D’Emic 2013) . The non-ungual phalanges are broader transversely than longer proximodistally. Three phalanges I.1 [a right one (SAV05-068.f, Fig. 20A–F ) from the holotype; a right one (SAV05-035.f, Fig. 21A–F ) from the paratype; and a referred left one (SAV05-057.b)]; and two phalanges II.1 [a right one (SAV05-068.g, Fig. 20G–L ) from the holotype; a right one (SAV05-035.g, Fig. 21G–L ) from the paratype] have been found at the fossil site. The phalanges I.1 and II.1 have a similar morphology. The dorsal surface of phalanx I.1 (mediolaterally narrower than the ventral one) is flat and medially and laterally bordered by rudimentary proximodistal crests (the dorsomedial and the dorsolateral crests), which separates it from the medial and lateral surfaces of the phalanx. The proximal surface is concave, has a semicircular-to-subrectangular outline (with a straight to concave ventral edge, Figs 20E , 21E ), and is perforated by a foramen in SAV05-38.f. The dorsal and the ventral edges of the proximal surface are proximally projected, covering part of the distal end of metatarsal I. The medial surface of this phalanx is flat and perforated by small foramina in the holotype specimen. The lateral surface is dorsoventrally and proximodistally shorter than the medial one and marked by a depression near the dorsolateral crest, especially developed in the smaller individuals (considered herein as an autapomorphy of Garumbatitan morellensis ). The ventral surface is proximodistally and mediolaterally concave and bears a small concavity near the medial distal condyle in the holotype and paratype specimen (absent in SAV05-057b). The distal condyles are individualized, extended to the ventral surface of the phalanx, dorsally connected, and ventrally projected; the medial condyle is shorter mediolaterally than the lateral one. In distal view, the medial condyle is medially bevelled (15–20°) and converges dorsally with the lateral one. The medial condyle is more ventrally projected than the lateral one. Both condyles are dorsoventrally elongated with sub-elliptical outlines. Near the ventral border of the distal surface, there is a wide intercondylar depression between the condyles.

The pedal phalanx II.1 is proximodistally longer than the phalanx I.1. In proximal view, phalanx II.1 has a semicircularto-‘heart’-shaped (concave ventral edge) outline with a smooth, and flat-to-concave surface (more concave in the paratype specimen than in the holotype one) ( Figs 20K , 21K ). A proximal surface of phalanx II.1 with a ‘heart’-shaped outline is considered as autapomorphic of Garumbatitan morellensis . Similarly, to pedal phalanx I.1, the dorsal surface of phalanx II.1 is flat and mediolaterally shorter than the ventral one (in the holotype, the dorsal surface is mediolaterally convex and poorly preserved). The dorsal surface is bordered by the proximodistal elongated dorsomedial and dorsolateral crests. The medial surface is also marked by a depression near the distal end, but shallower than in pedal phalanx I.1 (less pronounced in the holotype specimen). The lateral surface is flat, and the ventral surface is concave to smoothly concave in the paratype specimen (two small foramina are present in the paratype specimen). In the ventralmost area of the ventral surface, there is a small concavity near the distal end (absent in the holotype specimen). The distal condyles are individualized (dorsally connected), extending to the ventral face of the phalanx. An intercondylar depression is present between the distal condyles and near the ventral edge of the distal surface. This depression does not extend to the ventral surface of the phalanx. The condyles are dorsoventrally elongated (the medial one is lateromedially wider than the lateral one).

Only one right phalanx III.1 (SAV05-068.h, Fig. 20M–R ) was recovered belonging to the holotype specimen. It has a flat dorsal surface and bears some smooth rugosities. The lateral surface of this phalanx is dorsoventrally shorter than the medial one and it extends continuously to the dorsal surface. The medial surface is flat, separated from the dorsal edge by a smooth dorsomedial crest. The outline of proximal surface is unknown (the ventral edge is broken), but the dorsal edge is convex. The proximal surface is concave. The dorsal edge is slightly proximally projected. The distal end is covered by pedal phalanx III.2, and so it is not possible to describe it. The distal condyles extend to the ventral surface of the phalanx .

Two pedal phalanges IV.1 [a right one (SAV05-068.i, Fig. 20S–X ) from the holotype; and a right one (SAV05-035.h, Fig. 21Y –AD) from the paratype] are recognized (the distal condyle in phalanx IV.1 of the holotype is eroded). They are more dorsoventrally compressed than pedal phalanx III.1. The phalanx IV.1 of the paratype specimen seems to be mediolaterally more elongated than that of the holotype. The proximal surface is smoothly concave in the paratype and concave in the holotype, preserving an elliptical outline (mediolaterally elongated). The dorsal surface is concave proximodistally and convex mediolaterally. This surface is separated from the ventral surface by the ventromedial and ventrolateral crests (these crests are not pronounced). The ventral surface is concave in the paratype and flat in the holotype specimen (with two small foramina). The distal condyles are transversely expanded in the paratype specimen; however, this expansion is not visible in the holotype specimen due to the preservation. The condyles are not well-individualized and only slightly extended to the ventral surface.

There is one preserved pedal phalanx II.2 [the right one (SAV05-035.j, Fig. 21M–R ) from the paratype]. The phalanx II.2 is wedge-shaped in dorsal view being proximodistally constricted on the lateral side, producing a tongue-shaped structure. This phalanx is suboval in proximal view and bears a concave proximal surface with small circular foramina and some dorsoventral struts. The ventromedial edge of the proximal surface is ventrally projected bordering dorsally the ventral surface of the phalanx. The ventral surface is small and concave and perforated by a small foramen. The dorsal surface is proximodistally concave and extends continuously to the medial side up to the ventromedial crest, which separates the ventral surface from the medial one. The distal surface is marked two convex medial and lateral condyles, not well individualized dorsally but separated by a wide intercondylar concavity in the ventral half of the distal surface. The condyles extend to the ventral surface of the phalanx.

Two right phalanges III.2 were found: one in articulation with pedal phalanx III. 1 in the holotype specimen ( Fig. 20M–R ), and another one (SAV05-038.b, Fig.21S–X ) found near the left metatarsal III ( SAV05-38 .a), and it is considered as belonging to the right hindlimb of the paratype specimen. The pedal phalanx III.2 is larger than the phalanx II.2. The phalanx III.2 is wedge-shaped in dorsal view being proximodistally constricted on the lateral side (less proximodistally constricted than in the pedal phalanx II.2). This phalanx has a teardrop-shaped outline in proximal view (laterally constricted and with a ventral straight edge). The proximal surface is dorsoventrally concave and mediolaterally convex, rough, and bears some small foramina. The ventral edge of the proximal surface is ventrally projected, bordering dorsally the ventral surface, producing a tongue-shaped structure. The dorsal surface is flat, triangular (laterally constricted), and is separated from the medial face by the dorsomedial crest. The medial surface is flat to slightly concave. The ventral surface is sub-rectangular in ventral view but laterally constricted, being lateromedially and proximodistally concave (two foramina are present near the lateral edge). The distal surface is marked by two convex medial and lateral condyles, well individualized and dorsally connected but separated by a wide intercondylar concavity in the ventral half of the distal surface. The condyles extend do the ventral surface of phalanx and diverge ventrally (the medial condyle is dorsoventrally oriented and the lateral one is dorsomedially-ventrolaterally oriented).

Three pedal phalanx IV.2 were recognized [a right one (SAV05-068.j, Fig. 20Y –AD) from the holotype; a right one (SAV05-035.i, Fig. 21 AE– AJ) from the paratype; and a referred left one (SAV05-057.c)]. The pedal phalanx IV.2 is markedly proximodistally shorter than phalanx IV.1, and extremely mediolaterally larger than proximodistally. The proximal surface is elliptical and dorsoventrally compressed in proximal view. The proximal surface is flat (straight or smoothly convex mediolaterally). In the holotype the ventral edge of the proximal surface is proximally projected. The dorsal surface is continuous to the lateral and medial surfaces, resulting in a mediolateral convex surface and proximodistally concave. This surface is separated from the ventral surface by the ventromedial and ventrolateral crests. The distal condyles are individualized with a smooth intercondylar depression in the middle. They are projected ventrally and extend significantly to the ventral surface of the phalanx. The ventral surface of the phalanx is smoothly concave with a tuberosity in its medial half.

Two right pedal unguals I.2 [almost complete, from both holotype (SAV05-068.k, Fig. 22A–E ) and paratype (SAV05-035.k, Fig. 23A–E )]; one right pedal ungual II.3 [from the holotype specimen (SAV05-068.l, Fig. 22F–J ), which is badly preserved and separated in two pieces; and fragments from the left one of the paratype (SAV05-038.c)]; one right pedal ungual III.3 [from the paratype specimen (SAV05-35.l, Fig. 23F–J )]; and two right IV.3 [a complete one from the holotype (SAV05-068.m, Fig. 20 AE–AJ); and one from the paratype (SAV05-035.m, Fig. 21 AK–AP), which is badly preserved] were identified. Except the fourth ungual, all the unguals are sickle-shaped, much deeper dorsoventrally than broader transversely, with a convex dorsal edge, and concave ventral edge in lateral view. The ungual I.2 is less curved than the one from Tastavinsaurus sanzi ( Canudo et al. 2008) . The ungual I. 2 in the holotype specimen is dorsoventrally deeper than the ungual I.2 of the paratype specimen. They are mediolateraly compressed and bevelled laterally. The lateral and medial surfaces are dorsoventrally convex, and, in unguals I.2 and II.3, there is a longitudinal groove on both sides, the lateral one deeper than the medial one. The lateral groove does not curve and intersects the dorsal edge of the ungual at the distal end. The proximal surface is concave, dorsally constricted, and laterally deflected (this deflection is not present in Tastavinsaurus sanzi, Canudo et al. 2008 ). The phalanx III.3 lacks lateral and medial grooves, and it is markedly shorter than the ungual of the digits I and II, corresponding to 33% of the metatarsal III length, an autapomorphy of Garumbatitan morellensis . Near the proximal surface, there is a round tuberosity in the transition between the medial and ventral surfaces in the unguals I.2 and III.3. In the ungual I.2, there is another tuberosity in the distal half of the ventral edge, which appears in many titanosauriforms ( Canudo et al. 2008, Mannion et al. 2013, 2019a, b). The right phalanx IV.2 is rudimentary and oval (dorsoventrally compressed). The medial side is dorsoventrally constricted. The proximal surface is pierced by two foramina and the dorsal surface is transversely concave. The phalanx of the fifth toe is considered absent, also characteristic of Garumbatitan morellensis .

Figures

Figure 4. Garumbatitan morellensis, gen. et sp. nov., dorsal vertebra and dorsal ribs. Dorsal vertebra SAV05-40 (holotype) in posterior (A), dorsal (B), right lateral (C), left lateral (D), and ventral (E) views. Right middle dorsal rib SAV05-046 (paratype) in posteromedial (F), lateral (N), and medial (O) views; left anterior dorsal rib SAV08-101 (holotype) in lateral (H) and medial (I) views; left anterior dorsal rib SAV08- 102 (holotype) in lateral (J) and medial (K) views; left anterior dorsal rib SAV08-103 (holotype) in lateral (L) and medial (M) views; right anterior dorsal rib SAV05-047 (paratype) in medial (P) and lateral (Q) views. Missing edges indicated by dashed lines.Abbreviations: acr, anterior crest; cam, camella; cmr, camera; cr, crest; exp, expansion; gr, groove; mcr, medial crest; pcr, posterior crest; pf, pneumatic fossa; rdg, ridge. Scale bar equals 100 mm.

Figure 5. Garumbatitan morellensis, gen. et sp.nov., anterior caudal vertebrae from the holotype specimen.Anterior caudal vertebra SAV05-027 (A–F), SAV08-028 (G–L), SAV08-029 (M–R), SAV08-030 (S–X) in right lateral (A, G, M, S), anterior (B, H, N, T), left lateral (C, I, O, U), posterior (D, J, P, V), dorsal (E, K, Q, W; anterior towards right side), and ventral (F, L, R, X; anterior towards left side) views.Isolated anterior caudal neural spines SAV05-029 (Y–CC) and SAV05-030 (DD-HH) from the holotype specimen in dorsal (Y, DD), right lateral (Z, EE), anterior (AA, FF), left lateral (BB, GG), and posterior (CC, HH) views. Missing edges indicated by dashed lines. Abbreviations: acdl, anterior centrodiapophyseal laminae; acf, anterior chevron facet; cdr, caudal rib; f, fossa; fr, foramen; lr, lateral ridge; nc, neural canal; pcdl, posterior centrodiapophyseal laminae; posl, postspinal lamina; prsl, prespinal lamina; spol, spinopostzygapophyseal lamina. Scale bar equals 50 mm.

Figure 6. Garumbatitan morellensis, gen. et sp. nov., anterior and middle caudal vertebrae from the holotype specimen. Anterior caudal vertebra SAV05-060va in right lateral (A), anterior (B), left lateral (C), posterior (D), dorsal (E; anterior towards right side), and ventral (F; anterior towards left side) views.Middle caudal vertebra SAV05-061 in right lateral (G), anterior (H), left lateral (I), posterior (J), dorsal (K; anterior towards right side), and ventral (L; anterior towards left side) views. Missing edges indicated by dashed lines. Abbreviations: acf, anterior chevron facet; cdr, caudal rib; f, fossa; fr, foramen; lr, lateral ridge; nc, neural canal; pcf, posterior chevron facet; posl, postspinal lamina; prsl, prespinal lamina; poz, postzygapophyseal process; prz, prezygapophyseal process; rdg, ridge; spol, spinopostzygapophyseal lamina; sprl, spinoprezygapophyseal lamina; tb, tuberosity; tprl, intraprezygapophyseal lamina; vlr, ventrolateral ridge. Scale bar equals 50 mm.

Figure 7. Garumbatitan morellensis, gen. et sp.nov., middle-posterior caudal vertebrae from the holotype specimen. Middle-posterior caudal vertebrae SAV08-047, SAV08-048 and SAV08-049 in ventral (A; anterior towards right side), dorsal (B; anterior towards right side) and right lateral (C, D), anterior (I), and left lateral (J) views.Middle-posterior caudal vertebra SAV08-050 in dorsal (E; anterior towards left side), ventral (F; anterior towards right side), left lateral (G), and posterior (H) views.A, B, D, E, F, and J correspond to a 3D digital model. Missing edges indicated by dashed lines. Abbreviations: acf, anterior chevron facet; dp, depression; lr, lateral ridge; pbu, posterior bulge; pcf, posterior chevron facet; prsl, prespinal lamina; prz, prezygapophyseal process; rdg, ridge; sprf, spinoprezygapophseal fossa; sprl, spinoprezygapophyseal lamina; tprl, intraprezygapophyseal lamina.Scale bar equals 50 mm.

Figure 8. Garumbatitan morellensis, gen. et sp. nov., anterior chevrons from the holotype specimen.Anterior chevron SAV05-060chb (A–E), SAV05-063 (F–J), SAV05-060cha (K–O), and SAV05-060chc (P–T) in dorsal (A, F, K, P; anterior towards bottom side), anterior (B, G, L, Q), left lateral (C, H, M, R), posterior (D, I, N, S), and right lateral (E, J, O, T) views.Missing edges indicated by dashed lines. Abbreviations: acr, anterior crest; gr, groove; pcr, posterior crest; st, step. Scale bar equals 50 mm.

Figure 9. Garumbatitan morellensis, gen.et sp. nov., interclavicle SAV05-060chb from the holotype specimen in proximal (A), anterior (B), left (C), posterior (D), and right (E) views; and crosssection (F). Missing edges indicated by dashed lines.Abbreviations: fct, facet; gr, groove; rdg, ridge; str, striation. Scale bar equals 50 mm.

Figure 10. Garumbatitan morellensis, gen. et sp.nov., pubes from the paratype specimen. Left pubis SAV05-31b in posterior (A), lateral (B), anterior (C), and distal (E) views. Right pubis SAV05-31a in distal (D), posterior (F), and anterior (G) views. Missing edges indicated by dashed lines. Scale bar equals 50 mm.

Figure 11. Garumbatitan morellensis, gen. et sp. nov., right femur SAV05-024 from the holotype specimen in anterior (A, B*), medial (C*), posterior (D, F*) lateral (G*), and distal (E, I*) views; and cross-section of diaphysis at minimal diameter (E; anterior towards top side). *3D digital model. Missing edges indicated by dashed lines. Abbreviations: ep, epicondyle; fic, fibular condyle; lg, longitudinal groove; lic, linea intermuscularis cranialis; icg, intercondylar groove; icr, intercondylar ridge; plf, posterolateral fossa; tic, tibial condyle. Scale bar equals 100 mm.

Figure 12. Garumbatitan morellensis, gen. et sp.nov., femora from the paratype specimen. Left femur SAV05-031 in proximal (A), anterior (B), lateral (C), posterior (D), lateral (E), and distal (G) views. Right femur SAV05-013 in distal (F), anterior (H), lateral (I), posterior (J) and medial (K) views. Missing edges indicated by dashed lines. Abbreviations: ep, epicondyle; dp, depression; fh, femoral head; fic, fibular condyle; ft, fourth trochanter; lg, longitudinal groove; lic, linea intermuscularis cranialis; icg, intercondylar groove; mco, medial concavity to the fourth trochanter; plf, posterolateral fossa; st, step; tic, tibial condyle; ts, trochanteric shelf. Scale bar equals 100 mm.

Figure 13. Garumbatitan morellensis, gen. et sp. nov., right tibia (SAV05-065), fibula (SAV05-064) and astragalus (SAV05-066) from the holotype specimen in proximal (A*), anterior (B*), medial (C*), posterior (D*), lateral (E*), and distal (F*) views.*3D digital model. Abbreviations: acr, anterior crest; aspa, articular surface for the ascending process; cc, cnemial crest; lt, lateral trochanter; pvp, posteroventral process; tb, tuberosity; tia, tibial articular surface.Scale bar equals 100 mm.

Figure 14. Garumbatitan morellensis, gen. et sp. nov., tibiae from the paratype specimen.Right tibia (SAV05-032) in proximal (A), anterior (B), medial (C), posterior (D), lateral (E), and distal (F) views. Left tibia (SAV05-036) in proximal (I), anterior (G), medial (H), posterior (J), lateral (K), and distal (L) views. Missing edges indicated by dashed lines. Abbreviations: 2cc, second cnemial crest; aspa, articular surface for the ascending process; cc, cnemial crest; cr, crest; fia, fibular articular surface; pvp, posteroventral process.Scale bar equals 100 mm.

Figure 15. Garumbatitan morellensis, gen.et sp. nov., fibulae from the paratype specimen. Right fibula (SAV05-033) in proximal (A), lateral (B), anterior (C), medial (D), posterior (E), and distal (F) views. Left fibula (SAV05-037) in proximal (I), lateral (G), anterior (H), medial (J), posterior (K), and distal (L) views. Abbreviations: acr, anterior crest; cr, crest; lt, lateral trochanter; mli, medial lip; tia, tibial articular surface. Scale bar equals 100 mm.

Figure 16. Garumbatitan morellensis, gen.et sp. nov., right astragalus SAV05-034 from the paratype specimen in distal (A), proximal (B), lateral (C), posterior (D), anterior (E), and medial (F) views. Abbreviations: asp, ascending process; fia, fibular articular surface; fr, foramen; tia, tibial articular surface. Scale bar equals 50 mm.

Figure 17. Garumbatitan morellensis, gen. et sp. nov., right pes of the holotype (A, B) and paratype (C, D) specimens in proximal (A, C) and dorsal (B, D) views. Missing edges indicated by dashed lines.Scale bar equals 50 mm.

Figure 18. Garumbatitan morellensis, gen. et sp.nov., metatarsals from the holotype specimen.Right metatarsals I (SAV05-068.a), II (SAV05- 068.b, second row), III (SAV05-068.c, third row), IV (SAV05-068.d, fourth row), V (SAV05-068.e, fifth row) in dorsal (A, G, M, S, Y), medial (B, H, N, T, Z), ventral (C, I, O, U, AA), lateral (D, J, P, V, AB), proximal (E, K, Q, W; dorsal towards top side), and distal (F, L, R, X, AC; dorsal towards top side) views. Abbreviations: amt, articulation for metatarsal; dlcr, dorsolateral crest; dmcr, dorsomedial crest; icg, intercondylar groove; lc, lateral condyle; mc, medial condyle; mt, metatarsal; prj, proximal projection of the ventrolateral crest in the metatarsal II; vlcr, ventrolateral crest; vmcr, ventromedial crest. Scale bar equals 50 mm.

Figure 19. Garumbatitan morellensis, gen. et sp. nov., metatarsals from the paratype specimen.Right metatarsals I (SAV05-35.a, first row), II (SAV05-035.b, second row), III (SAV05-035.c, third row), IV (SAV05-035.d, fourth row), V (SAV05-035.e, fifth row) in dorsal (A, G, M, S, Y), medial (B, H, N, T, Z), ventral (C, I, O, U, AA), lateral (D, J, P, V, AB), proximal (E, K, Q, W, AC; dorsal towards top side), and distal (F, L, R, X, AD; dorsal towards top side) views. Abbreviations: amt, articulation for metatarsal; dmcr, dorsomedial crest; icg, intercondylar groove; lc, lateral condyle; mc, medial condyle; mt, metatarsal; prj, proximal projection of the ventrolateral crest in the metatarsal II; vlcr, ventrolateral crest; vmcr, ventromedial crest. Scale bar equals 30 mm.

Figure 20. Garumbatitan morellensis, gen. et sp. nov., pedal phalanges from the holotype specimen. Right phalanx I.1 (SAV05-068.f, first row), II.1 (SAV05-068.g, second row), III.1 and III.2 (SAV05-068.h, third row), IV.1 (SAV05-068.i, fourth row), IV.2 (SAV05-068.j fifth row) and IV.3 (SAV05-068.m, sixth row) in dorsal (A, G, M, S, Y, AE), medial (B, H, N, T, Z, AF), ventral (C, I, O, U, AA, AG), lateral (D, J, P, V, AB, AH), proximal (E, K, Q, W, AC, AI; dorsal towards top side), and distal (F, L, R, X, AD, AJ; dorsal towards top side) views.Abbreviations:dp, depression; fr, foramen; icg, intercondylar groove; lc, lateral condyle; mc, medial condyle. Scale bar equals 30 mm.

Figure 21. Garumbatitan morellensis, gen. et sp. nov., pedal phalanges from the paratype specimen. Right phalanx I.1 (SAV05-035.f, first row), II.1 (SAV05-035.g, second row), II.2 (SAV05-035.j, third row), III.2 (SAV05-038.b, fourth row), IV.1 (SAV05-035.h, fifth row), IV.2 (SAV05- 035.i, sixth row) and IV.3 (SAV05-035.m, seventh row) in dorsal (A, G, M, S, Y, AE, AK), medial (B, H, N, T, Z, AF, AL), ventral (C, I, O, U, AA, AG, AM), lateral (D, J, P, V,AB, AH, AN), proximal (E, K, Q, W, AC, AI, AO; dorsal towards top side), and distal (F, L, R, X, AD, AJ, AP; dorsal towards top side) views. Abbreviations: dp, depression; icg, intercondylar groove; lc, lateral condyle; mc, medial condyle.Scale bar equals 30 mm.

Figure 22. Garumbatitan morellensis, gen. et sp. nov., right pedal unguals I.2 (SAV05-035.k, A–E) and II.3 (SAV05-35.l, F–J) from the holotype specimen in dorsal (A, F), lateral (B, G), medial (C, H), proximal (D, I), and ventral (E, J) views.Abbreviations: dcr, dorsal crest; fr, foramen; gr, groove; pf, posterior face; tb, tuberosity. Scale bar equals 30 mm.

Figure 23. Garumbatitan morellensis, gen.et sp. nov., right pedal unguals I.2 (SAV05-068.k, A–E) and III.3 (SAV05-068.l, F–J) from the paratype specimen in dorsal (A, F), lateral (B, G), medial (C, H), proximal (D, I), and ventral (E, J) views. Abbreviations: dcr, dorsal crest; gr, groove; pf, posterior face; tb, tuberosity. Scale bar equals 50 mm.