taxonID	type	description	language	source
03AB87A8FFD17E64545EC1DAFDF55EEA.taxon	description	lsid: urn: lsid: zoobank. org: act: C 657 EC 04 - 18 D 2 - 45 F 0 - 8 E 4 E- CB 9 D 6 C 964626	en	Isasmendi, Erik, Cuesta, Elena, Díaz-Martínez, Ignacio, Company, Julio, Sáez-Benito, Patxi, Viera, Luis I., Torices, Angelica, Pereda-Suberbiola, Xabier (2024): Increasing the theropod record of Europe: a new basal spinosaurid from the Enciso Group of the Cameros Basin (La Rioja, Spain). Evolutionary implications and palaeobiodiversity. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (3): 1-34, DOI: 10.1093/zoolinnean/zlad193, URL: https://doi.org/10.1093/zoolinnean/zlad193
03AB87A8FFD17E64545EC1DAFDF55EEA.taxon	etymology	Etymology: Rioja (toponymy): in reference to La Rioja, the Spanish region where the holotype specimen was recovered, and venatrix: Latin for huntress.	en	Isasmendi, Erik, Cuesta, Elena, Díaz-Martínez, Ignacio, Company, Julio, Sáez-Benito, Patxi, Viera, Luis I., Torices, Angelica, Pereda-Suberbiola, Xabier (2024): Increasing the theropod record of Europe: a new basal spinosaurid from the Enciso Group of the Cameros Basin (La Rioja, Spain). Evolutionary implications and palaeobiodiversity. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (3): 1-34, DOI: 10.1093/zoolinnean/zlad193, URL: https://doi.org/10.1093/zoolinnean/zlad193
03AB87A8FFD17E64545EC1DAFDF55EEA.taxon	type_taxon	Type and only species: As for the type species (see below).	en	Isasmendi, Erik, Cuesta, Elena, Díaz-Martínez, Ignacio, Company, Julio, Sáez-Benito, Patxi, Viera, Luis I., Torices, Angelica, Pereda-Suberbiola, Xabier (2024): Increasing the theropod record of Europe: a new basal spinosaurid from the Enciso Group of the Cameros Basin (La Rioja, Spain). Evolutionary implications and palaeobiodiversity. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (3): 1-34, DOI: 10.1093/zoolinnean/zlad193, URL: https://doi.org/10.1093/zoolinnean/zlad193
03AB87A8FFD17E64545EC1DAFDF55EEA.taxon	diagnosis	Diagnosis: As for the type species (see below).	en	Isasmendi, Erik, Cuesta, Elena, Díaz-Martínez, Ignacio, Company, Julio, Sáez-Benito, Patxi, Viera, Luis I., Torices, Angelica, Pereda-Suberbiola, Xabier (2024): Increasing the theropod record of Europe: a new basal spinosaurid from the Enciso Group of the Cameros Basin (La Rioja, Spain). Evolutionary implications and palaeobiodiversity. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (3): 1-34, DOI: 10.1093/zoolinnean/zlad193, URL: https://doi.org/10.1093/zoolinnean/zlad193
03AB87A8FFD17E7A5422C2B2FD345BBF.taxon	description	lsid: urn: lsid: zoobank. org: act: F 5 E 10 E 99 - 9 BD 8 - 4384 - 9 FD 1 - 36575 E 24 B 05 D	en	Isasmendi, Erik, Cuesta, Elena, Díaz-Martínez, Ignacio, Company, Julio, Sáez-Benito, Patxi, Viera, Luis I., Torices, Angelica, Pereda-Suberbiola, Xabier (2024): Increasing the theropod record of Europe: a new basal spinosaurid from the Enciso Group of the Cameros Basin (La Rioja, Spain). Evolutionary implications and palaeobiodiversity. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (3): 1-34, DOI: 10.1093/zoolinnean/zlad193, URL: https://doi.org/10.1093/zoolinnean/zlad193
03AB87A8FFD17E7A5422C2B2FD345BBF.taxon	etymology	Etymology: Latin for ‘ related to a lake’, which declines from the word ‘ lacus ’ (lake).	en	Isasmendi, Erik, Cuesta, Elena, Díaz-Martínez, Ignacio, Company, Julio, Sáez-Benito, Patxi, Viera, Luis I., Torices, Angelica, Pereda-Suberbiola, Xabier (2024): Increasing the theropod record of Europe: a new basal spinosaurid from the Enciso Group of the Cameros Basin (La Rioja, Spain). Evolutionary implications and palaeobiodiversity. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (3): 1-34, DOI: 10.1093/zoolinnean/zlad193, URL: https://doi.org/10.1093/zoolinnean/zlad193
03AB87A8FFD17E7A5422C2B2FD345BBF.taxon	materials_examined	Holotype: A partial skeleton of a single individual, including: CPI 1637, left femur; CPI 1638, left tibia and astragalus; CPI 1639 A – B, left fibula; CPI 1640, left metatarsal III; CPI 1641 A – B, right ischium; CPI 1642, right tibia; CPI 1643, right femur; CPI 1644, possible fragment of metatarsal II; CPI 1645, left phalanx III- 1; CPI 1646, left phalanx III- 3; CPI 1647, left phalanx I- 2; CPI 1648, left phalanx IV- 2 (or IV- 3); CPI 1675 A – B, left pubis; CPI 1676, left calcaneum; and CPI 1677, fragment of a dorsal neural arch.	en	Isasmendi, Erik, Cuesta, Elena, Díaz-Martínez, Ignacio, Company, Julio, Sáez-Benito, Patxi, Viera, Luis I., Torices, Angelica, Pereda-Suberbiola, Xabier (2024): Increasing the theropod record of Europe: a new basal spinosaurid from the Enciso Group of the Cameros Basin (La Rioja, Spain). Evolutionary implications and palaeobiodiversity. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (3): 1-34, DOI: 10.1093/zoolinnean/zlad193, URL: https://doi.org/10.1093/zoolinnean/zlad193
03AB87A8FFD17E7A5422C2B2FD345BBF.taxon	diagnosis	Diagnosis: A medium- to large-sized spinosaurid theropod with the following unique combination of characters within Spinosauridae: (i) alateromediallythickandtriangularpubicbootindistalview, with a straight posterolateral margin (similar to Ichthyovenator, although in Ichthyovenator this margin is concave, but it is absent in Baryonyx, Suchomimus, and FSAC-KK 11888); (ii) an anteroposteriorly expanded ischial boot with an anterodorsally oriented tip and an angular anterodistal surface (absent in Ichthyovenator and FSAC-KK 11888; similar to Megalosaurus bucklandii); (iii) a narrow, restricted and relatively deep articular groove on the proximal surface of the femur, which is anteromedially – posterolaterally inclined (distinct from those of Baryonyx and Suchomimus); (iv) a medial femoral condyle with the long axis exhibiting only slight posteromedial orientation (distinct from those in Baryonyx, ‘ Spinosaurus B’ (Nr. 1922 X 45), Suchomimus, and FSAC-KK 11888); (v) presence of a vertical ridge on the medial margin of the ascending process of the astragalus (potential autapomophy, but it could also be a character in Spinosauridae because no other spinosaurid astragalus has been described to date); (vi) height of ascending process of the astragalus more than twice the height of the astragalar body (potential autapomophy, but it could also be a character in Spinosauridae because no other spinosaurid astragalus has been described to date); (vii) presence of an anterior depression with a dorsally located foramen on the lateral surface of the calcaneum (autapomorphy; absent in other spinosaurids); and (viii) absence of a longitudinal groove on the medial surface of phalanx I- 2 (potential autapomophy, but it could also be a character in Spinosauridae or even in Megalosauroidea; given that this element is not preserved in other spinosaurids or megalosauroids, a synapomorphy cannot be excluded).	en	Isasmendi, Erik, Cuesta, Elena, Díaz-Martínez, Ignacio, Company, Julio, Sáez-Benito, Patxi, Viera, Luis I., Torices, Angelica, Pereda-Suberbiola, Xabier (2024): Increasing the theropod record of Europe: a new basal spinosaurid from the Enciso Group of the Cameros Basin (La Rioja, Spain). Evolutionary implications and palaeobiodiversity. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (3): 1-34, DOI: 10.1093/zoolinnean/zlad193, URL: https://doi.org/10.1093/zoolinnean/zlad193
03AB87A8FFD17E7A5422C2B2FD345BBF.taxon	description	Description Axial skeleton Dorsal vertebra (Fig. 3): This piece consists of the mid- and posterior portions of the base of the neural arch, the bases of the transverse processes, and the neural spine of a mid- or posterior dorsal vertebra (CPI 1677). The neural arch does not preserve any of the zygapophyses. The thickness of the neural spine is constant across its anteroposterior length, but anteriorly, the interspinous ligament scar is present and slightly thickens the neural spine transversely (Fig. 3 A). The right spinodiapophyseal fossa is smooth, whereas the left one is more rugose. The transverse processes are horizontal in lateral view and slightly inclined dorsolaterally (Fig. 3 B). Anteriorly, the spinoprezygapophyseal laminae would have bounded a deep and dorsoventrally elongate spinoprezygapophyseal fossa, which is filled with matrix. This was inferred considering the distance between both laminae, the posterior extension of the fossa, and the considerable missing anterior portion of the spine (Fig. 3 A). On the posterior side, another fossa is present, interpreted here as the spinopostzygapophyseal fossa (Fig. 3 C). This fossa is also dorsoventrally elongate and deep, delimited by the spinopostzygapophyseal laminae. Ventrally, these laminae merge to form the hyposphene (Fig. 3 C). Underneath the left transverse process, a fragment of the posterior centrodiapophyseal lamina is centrally positioned, extending ventrally to the centrum (Fig. 3 B). Posterior to this lamina, the postzygocentrodiapophyseal fossa is present on the right side of the neural arch (Fig. 3 B). This fossa is also present on the left side, but it is less pronounced. Appendicular skeleton Pelvic girdle Pubis (Fig. 4 A – J): Two fragments of the left pubis are preserved (CPI 1675 A – B). The proximal fragment preserves the articular surface for the ischium, the surface of the acetabulum, and part of the iliac articulation (Fig. 4 A – E). The iliac articulation is broad, strongly rugose, and somewhat convex in proximal view (Fig. 4 E). Adjacent to the medial margin, an anteroposteriorly elongate concavity is present on this articular surface. However, this area is not well preserved and might be an artefact of abrasion. The iliac peduncle is not complete anteriorly, but it broadens towards the acetabular surface (Fig. 4 E). The medial surface of the iliac peduncle is straight, becoming convex near the acetabular surface in proximal view. Posterior to the iliac articular facet, the acetabular surface is a small triangular concavity, which is located medially on the proximal surface and is posteromedially inclined (Fig. 4 E). The ischial peduncle projects posteriorlyandtapersposterodistallytowardstheischialarticulation (Fig. 4 D). The ischial articulation is not completely preserved at the proximal end. It is triangular in posterior view and posteromedially directed (Fig. 4 D). The obturator notch is distally opened, relatively small anteroposteriorly, and subcircular (Fig. 4 B, C). The distal fragment of the left pubis (Fig. 4 F – J) lacks part of the symphysis and the medial portion of the distal expansion (Fig. 4 J). The shaft of the distal fragment is straight and shows a teardrop-shaped cross-section at the level of the symphysis. The pubic apron projects as a blade from the shaft (Fig. 4 J). The symphysis is almost entirely missing, but the preserved distal part is medially projected. Furthermore, it is sigmoidal in medial view, with a large distal extension. Based on the breakage surface, its development, and distalmost extension of the preserved apron, the pubic apron would have almost reached or slightly extended along the pubic boot (Fig. 4 J). The pubis is slightly expanded anteriorly on its distal end, and it has a greater posterior projection (Fig. 4 G, I). In distal view, the pubic boot is mediolaterally broad, especially at its centre (Fig. 4 H). Its anterior and medial surfaces are convex, whereas the lateral surface is gently concave. The posterior process of the pubic boot tapers posteriorly. Indistalview, thepubicbootistriangularinshape (Fig. 4 H). Ischium (Fig. 4 K – T): The right ischium preserves its proximal end (including the iliac peduncle), part of the shaft and the ischial boot (CPI 1641 A – B). Both lateral and medial surfaces of the iliac peduncle are convex (Fig. 4 Q). At the level of the surface of the acetabulum, the medial surface is flat and the lateral one is slightly concave, whereas near the pubic peduncle, the medial surface becomes concave and the lateral surface convex (Fig. 4 Q). In the posterior margin of the iliac peduncle, there is a dorsoventrally directed crest, forming a bulge near the dorsal margin. This bulge can be observed in medial and lateral views (Fig. 4 L – N). Anterior to this crest, the medial surface shows some proximodistally oriented furrows. The iliac peduncle is mediolaterally expanded, with an oval contour in proximal view (Fig. 4 Q). Although it is abraded, the articular surface of the iliac peduncle is concave posteromedially. A protuberance is present at the centre of the concavity, bounded anteriorly and medially by a groove. This concavity is anterolaterally delimited by a transversely oriented edge (Fig. 4 Q). The surface of the acetabulum bears a pronounced concavity that becomes shallower anteriorly. In proximal view, the acetabular surface has a medial crest, partly broken. This crest extends anteriorly from the anteromedial edge of the iliac articulation (Fig. 4 Q). The preserved cross-section of the ischial diaphysis is somewhat oval, with a rounded crest, posterolaterally directed, running longitudinally on the lateral surface of the shaft (Fig. 4 O, R, S). The posterior surface of the diaphysis is concave proximally and flattens towards the ischial boot, becoming a crest at the boot (Fig. 4 S). Both medial and anterior surfaces of the shaft are flat (Fig. 4 O, P). The ischial boot, triangular in medial or lateral view, is not strongly expanded anteroposteriorly and exhibits an angular anterodistal surface (Fig. 4 P, R). The posterior half of the lateral surface is convex, whereas the anterior half shows a concavity caused by the anterior process of the ischial boot (Fig. 4 R). This anterior process is connected to the diaphysis by a blade that becomes gradually less prominent proximally (Fig. 4 R). The blade is laterally inclined distally and becomes vertical proximally. The medial surface of the ischial boot is flat and shows some longitudinal striations that run proximally to the shaft (Fig. 4 P). In distal view, the ischial boot shows a triangular outline owing to the tapering of the anterior process (Fig. 4 T). Hindlimb Femur (Fig. 5): The right femur preserves only its proximal end (CPI 1643), and the left femur consists of most of the diaphysis and the distal articular end (CPI 1637). The femoral head is gently convex and subcircular in medial view (Fig. 5 D). Its proximodistal axis is slightly longer than the anteroposterior one. The femoral head is medially oriented and anteromedially directed at an angle of ~ 20 ° (Fig. 5 J). The proximal surface of the femur is posterolaterally inclined. There is an anteroproximally inclined groove (i. e. the oblique ligament groove) on the posterior surface (Fig. 5 C). This groove separates the femoral head from the shaft; therefore, the latter is well offset medially. Medial to this groove, the posterior lip of the femoral head is well developed and extends slightly beyond the posterior surface of the head (Fig. 5 C, J). The femoral head has a concave ventral surface. This surface becomes broader anteriorly, making the femoral head overhang the medial surface of the femoral diaphysis (Fig. 5 A, C). On the anterior side of the femoral head, there is an oblique ridge that extends from the femoral head to the proximal end of the diaphysis (Fig. 5 A). In proximal view, a deep, broad, and oblique articular groove can be noticed. This is more pronounced anteromedially and becomes shallower and narrower posterolaterally. In the same view, the femoral head is laterally confluent with the greater trochanter, which is incomplete and narrower than the head (Fig. 5 J). The left femur lacks the proximal end and the diaphysis proximal to the fourth trochanter. The preserved length of the left femur measures ~ 515 mm. The shaft of the femur is rather straight in anterior and posterior views, but it is anteriorly bowed in lateral and medial views (Fig. 5 E – H). The diaphysis is oval in cross-section, the mediolateral axis being larger than the anteroposterior one, with a maximum circumference of 322 mm. The anterior surface of the shaft is convex and slightly pinched in the middle (Fig. 5 E). The pinch extends 190 mm distal from the proximal fracture. Medial and lateral to this pinch, the surface becomes flat. The lateral surface is convex and becomes flat next to the distal expansion of the bone (Fig. 5 F). The medial surface is also convex but leads to a shallow and large concavity, which is located posterior to the medial epicondyle and extends until half of the medial condyle (Fig. 5 H). The posterior surface of the femoral shaft is flat and faces posterolaterally (Fig. 5 G). The fourth trochanter is located posteromedially in the proximal part of the preserved shaft. Only its most distal end is preserved, consisting of a well-developed and prominent longitudinal crest that becomes broader proximally (Fig. 5 G). Medially, there is a shallow and smooth groove; and laterally, there is a shallow, smooth, and broad concavity, which is excavated in the posterior surface of the diaphysis in lateral view. The distal end of the femur is slightly more medially than laterally expanded in posterior view (Fig. 5 G). The medial epicondyle or medial distal crest is found on the mediodistal surface. This medial epicondyle is rounded, low, and not well developed (Fig. 5 E). On the anterior surface of the medial epicondyle, the attachment for the muscle femorotibialis externus is a small rugose patch. The extensor groove is broad and slightly V-shaped in distal view (Fig. 5 I) and becomes even shallower and broader proximally (Fig. 5 E). The flexor groove is rather broad, deep, and U-shaped in distal view (Fig. 5 I). The flexor groove is bounded by two ridges medially and laterally, proximal to the condyles (Fig. 5 G). The medial ridge runs vertically from the proximal margin of the medial condyle, whereas the lateral ridge is more prominent and oblique, originating at the proximal end of the tibiofibular crest. The medial crest merges with the shaft proximally. The anterior surface of the lateral condyle is rounded. The medial condyle is slightly more flattened and anterolaterally oriented in the anterior surface (Fig. 5 E). At the distal end, the condyles are robust, being wide mediolaterally. Both medial and lateral condyles project distally to an almost equal extent in anterior view (Fig. 5 E). In the same view, the lateral condyle projects distally and slightly laterally, whereas the medial condyle is solely distally projected. The medial condyle is teardrop-shaped in posterior view (Fig. 5 G). In distal view, the lateral condyle is rounded and the medial one is more elliptical with the long axis slightly posteromedially oriented (Fig. 5 I). The distal condyles are not separated by an anteroposterior pronounced groove in the distal surface, but there is a central shallow groove that connects to the tibiofibular crest (Fig. 5 I). The tibiofibular crest is broad and positioned on the posterior surface of the lateral condyle (Fig. 5 G, I). In posterior view, the crista tibiofibularis is teardrop-shaped and oblique with respect to the long axis of the lateral condyle (Fig. 5 G). The tibiofibular crest is somewhat trapezoidal in distal view. This is laterally bounded by a broader groove, and medially, a narrow and deep groove separates the crest from the distal margin of the condyle or the flexor groove. Between both grooves, there is a posterolaterally elevated ridge in distal view (Fig. 5 I). Tibia (Figs 6 A – J, 7 A – E): The right tibia (CPI 1642) preserves only its proximal portion (Fig. 6 A – D, I). The left tibia (CPI 1638) is complete, including the articulated astragalus (Figs 6 E – J, 7 A – E). The right tibia lacks the cnemial crest and the medial condyle. However, the lateral condyle and the proximal end of the fibular crest are well preserved. The left tibia shows many furrows on the medial surface close to the proximal end. Furthermore, these are also present on the anterior margin of the medial malleolus. The shaft of the left tibia is straight and fairly robust, with a length of ~ 810 mm (Fig. 6 E – H). The cross-section of the tibial diaphysis is oval, where the mediolateral axis is the largest. At mid-shaft, the diaphysis narrows laterally and becomes wider medially. In lateral view, the anterior surface of the tibia is concave proximally, becoming convex distally. The posterior surface is rather straight close to the proximal end and concave distally. The anterior surface is flat and the posterior surface gently convex along the whole shaft. The lateral surface is convex, whilst the medial margin is flat proximally and becomes concave at mid-shaft. The cnemial crest of the left tibia is rounded (Fig. 6 E, F). Dorsally, it expands mediolaterally and flexes laterally in anterior view. The cnemial crest projects from the anterior surface of the diaphysis beyond the proximal articular surface of the tibia (Fig. 6 E, F). The lateral surface of the cnemial crest bears a longitudinal tuberosity near its anteroposterior corner (Fig. 6 F, J). In proximal view, the lateral condyles are offset from the cnemial crest by a poorly developed incisura tibialis (Fig. 6 I, J). The lateral condyles are large, rounded, and broad. The preserved portions of both medial condyles suggest that they were also large. There is no process extending anterolaterally from the lateral condyle in either tibia, but there is a notch present between the medial and lateral condyles in the right tibia (Fig. 6 I). In proximal view, the posterior outline of the left tibia is nearly straight owing to the lack of the medial condyle, whereas the medial surfaces are smoothly convex in both tibiae. The fibular flange is a low longitudinal crest with a slightly broadened base (Fig. 6 E – G). It is situated proximally on the lateral surface of the diaphysis, but it is distally located to the proximal end of the tibia. The outline of the base of the fibular crest is oval, but narrow, in lateral view (Fig. 6 F). This is separated from the proximally located lateral process associated with the fibular crest. In the right tibia, the proximal end of the lateral process associated with the fibular crest also reaches the proximal end of the tibia (Fig. 6 B, E – G). These processes are rounded and proximodistally oriented (Fig. 6 B, F). The distal end of the tibia is expanded mediolaterally, being anteroposteriorly narrower. Both the lateral and medial malleoli extend somewhat equally distally, with the lateral malleolus being larger and slightly more distally projected than the medial one (Figs 6 E, G, 7 A, C). This makes the distal surface almost horizontal, being ~ 15 ° with respect to the horizontal or ~ 75 ° with respect to the long axis of the tibial shaft. The lateral malleolus is rounded and the medial one more angled in posterior view (Figs 6 G, 7 C). In medial view, the medial malleolus shows a flat surface bounded posteriorly by a longitudinal ridge, which is mediodistally inclined (Figs 6 G, H, 7 C, D). The medial malleolus is transversely wider and more robust than the lateral one. The facet for the fibula shows longitudinal furrows and occupies a large portion of the anterior surface of the lateral malleolus (Figs 6 E, F, 7 A, B). The astragalar facet of the tibia is high (~ 150 mm), broad, and triangular and occupies more than half of the distal end of the anterior surface of the tibia (Figs 6 E, 7 A). This facet is delimited proximomedially by the supraastragalar buttress. The latter is developed as a well-developed and bluntly rounded ridge. It originates mediodistally and it is almost vertical basally, becoming a low oblique ridge proximally. The supraastragalar buttress is more pronounced distally and gradually fades proximolaterally (Figs 6 E, 7 A). Fibula (Fig. 6 K – T): The left fibula (CPI 1639 A – B) is almost complete but lacks part of the distal diaphysis. The fibula is a slender bone with a rather thin shaft and with an estimated length of 750 mm. The proximal end is strongly expanded anteroposteriorly and slightly expanded mediolaterally. Furthermore, the fibula is deformed, displaying an S-like shape at ~ 340 mm from its proximal end. Below the S-like deformation, the shaft of the fibula is somewhat twisted, a feature that might be associated with the deformation (Fig. 6 K – N). The proximal end of the fibula is more posteriorly than anteriorly expanded (Fig. 6 L, N). The posterior margin of the proximal fibula becomes thinner posteriorly to form a thin, blade-shaped margin (Fig. 6 O). This margin is more rounded than the anterior one in medial view, which is more acute in lateral view (Fig. 6 L, N). The proximal margin is slightly concave at the level of the medial fossa and becomes convex near the anterior and posterior margins in lateral view (Fig. 6 L, N). In proximal view, the proximal margin of the fibula is comma-shaped, with the anterior margin being wider than the posterior one (Fig. 6 O). The medial fossa reaches the proximal margin and occupies half the expansion of the proximal end of the tibia. It is shallow, inverted teardrop-shaped, and centrally positioned in medial view (Fig. 6 N). Anteriorly, the medial fossa is bounded by an elevated edge, which creates the anterior margin of the proximal end and broadens proximally. The posterior margin of the medial fossa is posteriorly opened (Fig. 6 N). Below the medial fossa, the medial surface is planar. In the shaft, a posteromedially located low ridge runs ventrally and becomes oblique below the iliofibularis tubercle, bounding an anterior groove on the medial surface. At the level of this tubercle, a shallow depression can be noticed on the medial surface of the shaft (Fig. 6 N). Below the oblique ridge, a proximally well-developed groove is present, which extends parallel to the diaphysis distally. The posterior edge of this groove consists of a medially raised edge. Distally, the groove fades at the distal end of the preserved shaft when the diaphysis expands (Fig. 6 N). At the proximal expansion of the fibula, the lateral surface is convex anteriorly, becoming almost flat in the middle of the lateral side and again slightly convex posteriorly (Fig. 6 L). Some longitudinal furrows are present on the anterolateral surface of the fibula. Posteriorly, the proximolateral surface of the fibula has a longitudinal and vertically oriented depression. Another broader, but slightly shallower depression is present on the anterolateral surface, at the same level as the posterior one (Fig. 6 L). The fibular diaphysis has a strongly convex lateral surface, but it is more planar at the level of the iliofibularis tubercle. The insertion for the iliofibularis muscle is located on the anterior margin of the fibular shaft, approximately at one-third from the proximal surface (Fig. 6 K, L, N). It is low and rugose in anterior view and is formed by two protuberances, which are bounded laterally by a longitudinal, shallow, and rugose groove (Fig. 6 K, L, N). The distal end is expanded anteroposteriorly and transversely. At the beginning of the distal expansion, both anterior and posterior edges are sharp. Distally, the anterior part is rounded (Fig. 6 P), whereas the posterior margin is sharp edged and slightly inclined laterally (Fig. 6 R). The medial surface for the articulation with the tibia is flat proximally (Fig. 6 S). However, in distal view, the anterior portion of the medial surface appears convex, becoming concave posteriorly (Fig. 6 T). On the lateral surface of the distal expansion, an oblique ridge starts anteroproximally and runs posterodistally down to the ventral end (Fig. 6 Q). Posteroproximally, overlying this ridge, there is a shallow and broad depression. The distal outline of the fibula is teardrop-shaped. This surface shows a depression anteromedially and becomes convex posteriorly (Fig. 6 T). Astragalus (Figs 6 E – H, 7 A – E): The left astragalus is almost complete (CPI 1638), lacking only part of the anterodistal margin of the medial condyle of the astragalar body. The astragalus is L-shaped in lateral view, with a relatively tall ascending process (Figs 6 E, F, 7 A, B). The astragalus measures 155 mm in height and 122 mm mediolaterally. In anterior view, the astragalar body shows an hourglass shape, with concave distal and proximal surfaces (Figs 6 E, 7 A). However, the distal concavity is broader and less pronounced than the dorsal one. In distal view, the astragalar body is rectangular (Fig. 7 E). The medial condyle of the astragalus is expanded anteroposteriorly. There is a shallow distal groove, becoming broader and slightly deeper laterally. The groove is bounded anteriorly by a parallel low crest that is slightly more prominent laterally and almost reaches the astragalus – calcaneum contact (Fig. 7 E). In anterior view, there is another groove, horizontal and shallow, developed between the condyles, at the mid-height of the astragalar body (Fig. 7 A). This groove has its maximum depth medially, gradually gets shallower laterally, and extends until the lateral rim. There is a bulge on the groove. Between the astragalar body and the ascending process, there is a depression; hence, the ascending process is offset from the astragalar body (Fig. 7 B). This depression is broader and more marked laterally, showing a triangular shape in proximal view. The facet for the fibula is not preserved. The medial side of the posterior margin of the astragalar body is more proximally projected than the lateral side (Fig. 7 C). This posterior margin is gently convex over most of its extension, but laterally it becomes shorter and slightly concave. The astragalar body is smooth on most of its anterior surface. Nonetheless, the area that articulates with the calcaneum is rugose. The medial condyle is more anteriorly projected than the lateral one in ventral view; hence, the astragalus is narrower laterally (Fig. 7 E). Besides the anteroposterior expansion of the astragalar body, the distal condyles are oriented anterodistally. The distal condyles of the astragalus are rounded anteroposteriorly (Fig. 7 E). The ascending process of the astragalus is laminar, triangular, and proximolaterally oriented (Fig. 7 A). The height of the ascending process is twice the height of the astragalar body, with the former measuring ~ 103 mm and the latter 52 mm. The ascending process is located slightly laterally, and it does not reach the lateral margin of the astragalar body (Fig. 7 A). It arises at around one-fifth from the medial margin of the astragalar body. The process is transversely broad, with its base extending mediolaterally ~ 65 % of the transverse width of the astragalar body. The medial margin of the ascending process shows a well-defined ridge that is perpendicular to the mediolateral axis of the astragalar body and arises from the anterodorsal surface of the astragalar body (Fig. 7 A). This ridge is parallel to the ventral part of the astragalar buttress of the tibia. The ridge fades where the ascending process tilts laterally at an angle of 40 – 45 ° with respect to the long axis of the tibia. Proximally, this margin gradually becomes oriented more transversely. The lateral margin of the ascending process is rather straight and vertical (Fig. 7 A). The proximal end of the ascending process is placed at three-quarters of the transverse width of the astragalar body from the medial side. The ascending process does not contact the supraastragalar buttress (Fig. 7 A). Calcaneum (Fig. 7 F – K): The left calcaneum (CPI 1676) is complete, with a height of 63 mm. Its anteroposterior width measures 72 mm, whereas its mediolateral width is 29 mm. The contact of the calcaneum with the astragalus is slightly sinuous, and the tibia overlaps the calcaneum. The calcaneum is reniform anteriorly and laterally (Fig. 7 H, I). In lateral view, the anteroproximal margin is more proximally elevated than the posteroproximal margin (Fig. 7 I). The proximal rim is concave for the articulation with the fibula, and the proximal articular surface is proximally directed. The articulation for the distal end of the fibula is well developed (Fig. 7 F). The distal profile is strongly convex in lateral view (Fig. 7 I). In proximal view, the calcaneum is anteriorly broad, narrowing posteriorly, with a sharp edge that is oriented posterolaterally (Fig. 7 F). This edge broadens distally and has a crescent shape in order to accommodate the lateral malleolus of the tibia (Fig. 7 J). The lateral surface has a broad vertical groove and another anteriorly located depression. The latter is as deep as the groove, triangular, and bears a foramen at its proximalmost point (Fig. 7 I). Between the groove and the depression, a triangular convexity is present. The medial surface of the calcaneum shows a concave facet for the lateral malleolus and an anteriorly located groove to articulate the lateral condyle of the astragalus. The groove is posteriorly inclined and parallel to the anterior margin of the calcaneum (Fig. 7 K). Metatarsal III (Fig. 8 A – F): The left metatarsal III is complete (CPI 1640). The diaphysis is straight, measuring 364 mm proximodistally, and with a subrectangular cross-section at mid-shaft (Fig. 8 C – E). Its borders are rounded, except for the medial surface, which is planar. Its proximal end is anterodorsally and posteroventrally expanded, especially posteroventrally projected in lateral view (Fig. 8 C, E). In proximal view, metatarsal III has an hourglass-shaped outline, the anterodorsal part of which is more lateromedially expanded than the posteroventral one (Fig. 8 F). The articular surface for metatarsal II is proximally located in the medial surface of metatarsal III (Fig. 8 E). It is concave, densely striated, and reaches the middle of the diaphysis. The articular surface for metatarsal IV is posteroventrally concave and convex anterodorsally close to the proximal end of metatarsal III (Fig. 8 C). This surface is also striated, as in the articulation for metatarsal II. The medial articular surface is bounded anterodorsally and posteroventrally by two elevated edges that fade distally. The posteroventral edge is more pronounced than the anterodorsal one. On the anterodorsal surface, there is a marked scar (Fig. 8 B). Another scar is located on the posteroventral surface, below the proximal expansion (Fig. 8 D). The distal condyle is divided posteroventrally by a shallow groove (Fig. 8 A). On the anterodorsal surface, there is no marked hyperextensor pit; however, a subtle depression is present adjacent to the condyle (Fig. 8 A, B). The distal condyle is subrectangular in distal view, with the medial side being anterodorsally and posterooventrally larger than the lateral side (Fig. 8 A). The medial collateral ligament pit is much deeper and larger than the lateral one. Both of them are suboval (Fig. 8 C, E). Phalanx I- 2 (Fig. 8 G – K): CPI 1647 is interpreted as the ungual phalanx of digit I based on the small size of the element (it measures 63 mm proximodistally) and its significant curvature. This (left) phalanx is complete. It is long, narrow, distally pointed, and strongly arched in lateral and medial views (Fig. 8 H, J). The phalanx I- 2 is triangular in cross-section but has an oval articular surface in proximal view (Fig. 8 K). The articular surface for the articulation of phalanx I- 1 is concave. This surface is slightly pointed dorsally in proximal view, and the proximodistal lip is not well developed. Ventrally, this surface is rounded. The flexor tuberosity, placed on the ventral side of the articular surface, is not very pronounced, but it is more developed than the lip (Fig. 8 K). Both medial and lateral surfaces are convex proximally, but the lateral surface is slightly flatter (Fig. 8 H, J). The dorsal surface of phalanx I- 2 is convex, and the ventral side is comparably flatter (Fig. 8 G, I). There are no ventral or flexor fossae. Both medial and lateral margins are softly convex; hence, this phalanx is symmetrical. Only the lateral surface bears a longitudinal groove. This is well developed and faces at about two-thirds proximally, becoming progressively shallower (Fig. 8 H). Phalanx III- 1 (Fig. 8 L – Q): CPI 1645 is interpreted as a proximal phalanx because it lacks a proximal keel. Furthermore, it can be assigned confidently to digit III based on the rather symmetrical distal condyles and not as asymmetrical proximal articular surface. The left phalanx III- 1 is virtually complete, measuring 118 mm in length, with the flexor tubercle partly eroded and lacking the ventral part of the medial condyle. The height and width of the phalanx change proximodistally, being higher proximally. Between both articular surfaces, the neck constricts the phalanx, especially ventrally, such that the phalanx is wider than tall at mid-shaft (Fig. 8 N, Q). The dorsal margin is smooth and gently convex, becoming flat and inclined distally. Above the proximal margin of the collateral ligament pits is the extensor fossa (Fig. 8 M). It is deep and oval, with the longest axis directed transversely. The ventral surface is also slightly mediolaterally convex, but proximodistally concave in lateral and medial views (Fig. 8 M, P, Q). Proximally, there is a proximolaterally oriented oblique groove that separates the flexor tubercle into two processes. The proximal articular surface is devoid of any keel separating the articular facets. This surface is weakly concave and subcircular, with a pronounced, medially inclined proximodorsal lip. This surface is partly deformed (Fig. 8 O). Close to the proximal end, there is a proximoventral fossa on both medial and lateral sides (Fig. 8 N, Q). These are rugose and roughly triangular. Distally, the lateral collateral ligament pit is subcircular and deeper than the medial one. The medial collateral ligament pit extends more proximally and is oval (Fig. 8 N, Q). Both condyles are equally developed (Fig. 8 L). The long axis of the lateral condyle is inclined slightly laterally and the medial condyle is somewhat inclined medially. The lateral condyle is slightly more dorsally and ventrally projected, whereas the medial condyle is slightly more distally projected (Fig. 8 M, P). The condyles are separated by a shallow intercondylar sulcus. In distal view, the condyles are mediolaterally expanded on the ventral surface. In ventral view, the lateral condyle ends more abruptly proximally or, at least, it is more pronounced than the medial one (Fig. 8 P). Phalanx III- 3 (Fig. 8 R – W): CPI 1646 can be attributed confidently to digit III because of the symmetry of the distal condyles and the proximal articular surface. The specimen is not a proximal phalanx because it presents a keel on the proximal surface and is here identified as phalanx III- 3 based on the position of the collateral ligament pits, which are dorsally displaced, and the lack of a dorsal extensor fossa. The left phalanx III- 3 is complete and almost symmetrical axially. Compared with phalanx III- 1, this is smaller, measuring 67 mm in length, but stouter and proportionally broader transversely. It is taller and wider proximally and distally. The neck of phalanx III- 3 especially constricts the pedal element. The dorsal surface is convex, but concave in lateral or medial view (Fig. 8 T, W). There is no extensor fossa on the dorsal surface of this phalanx (Fig. 8 S). The ventral surface is flat, but it is also concave in medial or lateral view (Fig. 8 T, W). Two rounded and considerably broad proximoventral crests are present, and they are bounded medially and laterally by a rugose area (Fig. 8 T, V, W). Proximally and centrally positioned on the ventral surface, there is a process. The proximal end of the process is missing, but the preserved part is broad, rounded, and proximodistally oriented. The proximal articular surface is triangular in outline in proximal view, with a well-developed and centred proximodorsal lip (Fig. 8 U). A vertical median keel separates the lateral and medial articular facets. Both articular facets are equally developed and subsymmetrical. In medial and lateral views, the proximoventrally located fossae are less developed in phalanx III- 3 than in phalanx III- 1 (Fig. 8 T, W). On the medial side, the fossa is restricted to a triangular rugose patch. On the lateral margin, this fossa is oval and very small. Both collateral ligament pits are more dorsally placed, in comparison to phalanx III- 1. These pits are deep, subcircular to oval, and almost equally developed. The distal condyles are not symmetrical. The medial condyle is more dorsoventrally developed compared with the lateral one (Fig. 8 R). The long axis of the lateral condyle is laterally oriented, and it is medially directed in the medial condyle. In ventral view, the lateral condyle ends more abruptly proximally (Fig. 8 V). Phalanx IV- 2 (or IV- 3) (Fig. 8 X – AB): There is a proximal fragment of a left pedal phalanx IV- 2 or IV- 3 (CPI 1648). This identification is based on high asymmetry of the proximal articular surface, which indicates that it would be from the digit IV. Furthermore, the presence of a keel on the proximal articular surface and the relatively large size of the element suggest that it would not be the distalmost non-ungual phalanx of digit IV. This fragment broadens and increases in height proximally. The neck of the phalanx would also contract the bone (Fig. 8 X, Y, AA, AB). At this level, it is triangular in cross-section with rounded margins. The dorsal surface of this phalanx is convex, but it is concave in lateral or medial view (Fig. 8 Y, AB). The preserved ventral surface shows a smooth fossa, which is bounded by two proximoventral ridges (Fig. 8 AA). The lateral ridge is broader than the medial one. Close to the proximal rim, there is a rugose surface. At the proximal rim, there is a centred proximal process. In proximal view, the proximal articular surface is triangular and bears a median keel that separates both articular surfaces for the condyles (Fig. 8 Z). The proximodorsal lip is highly pronounced and medially directed. The lateral articular facet is smaller but deeper than the medial one. The lateral articular facet is triangular (almost right-angled triangular) in proximal view, and the medial one is oval. Dorsal to the proximoventral ridges, there are no proximoventral fossae. In this area, a triangular rugose surface is present on both sides (Fig. 8 Y, AB).	en	Isasmendi, Erik, Cuesta, Elena, Díaz-Martínez, Ignacio, Company, Julio, Sáez-Benito, Patxi, Viera, Luis I., Torices, Angelica, Pereda-Suberbiola, Xabier (2024): Increasing the theropod record of Europe: a new basal spinosaurid from the Enciso Group of the Cameros Basin (La Rioja, Spain). Evolutionary implications and palaeobiodiversity. Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (3): 1-34, DOI: 10.1093/zoolinnean/zlad193, URL: https://doi.org/10.1093/zoolinnean/zlad193
