Turnersuchus hingleyae, Wilberg & Godoy & Griffiths & Turner & Benson, 2023

Wilberg, Eric W., Godoy, Pedro L., Griffiths, Elizabeth F., Turner, Alan H. & Benson, Roger B. J., 2023, A new early diverging thalattosuchian (Crocodylomorpha) from the Early Jurassic (Pliensbachian) of Dorset, U. K. and implications for the origin and evolution of the group, Journal of Vertebrate Paleontology 42 (3), pp. 1-23 : 3-16

TURNERSUCHUS HINGLEYAE sp. nov.

( Figs. 1–9 )

Holotype — LYMPH 2021/45 , partial skull, partial mandible, cervical and dorsal vertebrae in articulation and isolated caudal vertebrae, cervical and dorsal ribs, right pectoral girdle (right scapula and partial right coracoid), partial right humerus, ulna, partial tibia, one dorsal osteoderm.

Etymology —After Elizabeth “Lizzie” Hingley, who discovered additional material and prepared the specimen.

Locality and Horizon — Uptonia jamesoni chronozone of the Belemnite Marl Member of the Charmouth Mudstone (Lower Jurassic, Pliensbachian). Recovered as eroded material adjacent to the beach approximately one kilometer west of the Charmouth Heritage Coast Centre, Charmouth , Bridport DT66LL, U.K.

Diagnosis —Thalattosuchian crocodylomorph with the following unique combination of characters (autapomorphies indicated by an asterisk*): dorsally directed prootic peg along suture with parietal*; enlarged median pharyngeal foramen*; quadrate broadly separated from trigeminal foramen*; tall, vertically oriented squamosal occipital surface*; posterolateral corner of supratemporal fossa well posterior to occipital condyle; squamosal fossa facing slightly ventrally*; scapula with anterior margin more strongly concave than posterior margin. Differs from Pelagosaurus in: posterior margin of the supratemporal fenestra more posterolaterally inclined; supratemporal fossa extending further posterolaterally; squamosal fossa oriented slightly ventrally; tall, vertical occipital surface of squamosal; scapula with relatively straight posterior margin; ulna broader proximally, with more strongly curved shaft. Differs from Plagiophthalmosuchus in: tall, vertical occipital surface of squamosal; broader intertemporal bar (at least anteriorly); anteroposteriorly shorter retroarticular process lacking a distinct ridge on the dorsal surface.

DESCRIPTION

General Description

The specimen is relatively three-dimensionally preserved and in partial articulation, with elements preserved in five separate blocks ( Fig. 1 ) that were recovered over a period of 15 months (May 2017–July 2018), due to gradual weathering, from the type locality. Preserved cranial material consists primarily of elements from the posterior right side including much of the braincase and occipital region, all of which are preserved in the main block (or block 1). Mandibular fragments are preserved in blocks 1 and 3 (which was prepared away from block 1) and include both retroarticular processes and small isolated fragments of both the dentaries and angulars. The axial and appendicular elements are preserved in four of the blocks, with the cervical and dorsal vertebrae in blocks 1 and 2 preserved in articulation. Blocks 4 and 5 preserve caudal vertebrae. Preserved appendicular elements include the right scapula, coracoid, and humerus (block 1), right ulna (block 2), and an isolated long bone fragment (possibly a distal tibia). Numerous ribs and rib fragments are preserved among the blocks, as well as at least one dorsal osteoderm (block 1). Additional photographs of all blocks and isolated elements are available at www. morphobank.org/permalink/?P4271.

Major Cranial Openings

Choana —The choana itself is not preserved, but the preserved portion of the pterygoid shows that it opened into a broad depression on the ventral surface of the pterygoid ( Fig. 2 ). It terminates posteriorly at a short, gently curving (concave anteriorly) ridge, similar to that of Pelagosaurus typus (NHMUK PV OR 32599; Mueller-Töwe, 2006), but differing from the shallower depression marking the posterior margin of the choana of some other thalattosuchians (e.g., Teleosaurus ; Jouve, 2009). The relatively posterior position of this posterior margin of the choana suggests a more extensive secondary palate than present in “sphenosuchian” grade basal crocodylomorphs and protosuchids ( Dollman & Choiniere, 2022).

Supratemporal Fenestra —Much of the right supratemporal fenestra (STF) is preserved, lacking its anterior and anterolateral margins ( Fig. 2 ). The posterior portion of the intertemporal bar is also incomplete. The STF is large with a well-developed fossa posteriorly (and somewhat medially). The medial margin is formed by the frontal and parietal, the posterior margin by the parietal and squamosal, and the lateral margin by the squamosal and postorbital. The posterior margin is inclined posterolaterally at approximately 50°. The posterolateral corner greatly exceeds the occipital condyle posteriorly, though this might be exaggerated by the slight postmortem displacement of some of the cranial elements. This posterolateral inclination of the posterior margin of the STF is greater than that of Pelagosaurus (∼65°; NHMUK PV OR 32599), or Plagiophthalmosuchus (∼65°; NHMUK PV OR 15500). Lack of preservation of the anterior portion of the STF prevents detailed description of its shape, but based on the preserved portions, the STF is anteroposteriorly longer than mediolaterally wide.

Temporo-orbital Foramen —The temporo-orbital foramen is visible in dorsal view on the posterior wall of the supratemporal fossa ( Fig. 2 ). The squamosal forms its lateral and short parts of the dorsal and ventral margins. The parietal forms the remainder of the dorsal border. The prootic appears to form the medial and remainder of the ventral border, potentially excluding the quadrate from the margin of the foramen. However, sutures are difficult to discern in this region.

Cranioquadrate Canal —Part of the right cranioquadrate canal is preserved ( Fig. 3 ). It is positioned laterally on the occipital surface, between the paroccipital and inferolateral processes of the otoccipital. The otoccipital forms the dorsal, medial, and inferior borders. As preserved, the canal is open laterally. However, the lateral surface of the quadrate and inferior portion of the squamosal fossa are damaged. Thus, it is possible that the canal was fully enclosed by some combination of these bones.

Foramen Magnum —The inferior and right lateral borders of the foramen magnum are preserved ( Fig. 3 ). The otoccipital forms the lateral and a small part of the inferior borders. The basioccipital forms the remainder of the inferior border. The superior border is not preserved so it is unclear whether the supraoccipital would have contributed to the superior border.

Bones of the Skull

Frontal —Most of the frontal is missing from the specimen ( Figs. 2 , 3 ). The wider, anterior-most preserved portion of the intertemporal bar likely preserves the posterior-most part of the posterior process of the frontal. However, the suture with the parietal is not obvious in the scan. The dorsal surface of this portion of the intertemporal bar preserves a few anteroposteriorly elongate oval pits, suggesting ornamentation of this element similar to that of the postorbital and squamosal.

Parietal —The parietal is a single, fused element in LYMPH 2021/45, though only portions of it are preserved ( Figs. 2 , 3 ). The parietal is Y-shaped, with an anterior process and right and left posterolateral processes (of which only the right is preserved). The anterior process articulates with the frontal anteriorly, the laterosphenoid, and prootic inferolaterally. The parietal makes up most of the intertemporal bar, though uncertainty of the position of the frontal suture and damage to the posterior region of the bar prevents giving exact proportions. The surface bone is missing on the posterior region of the intertemporal bar, so it is unclear if a narrow sagittal crest would have been present as in most metriorhynchids, or if the intertemporal bar would have maintained its width throughout as in Pelagosaurus (NHMUK PV OR 32599; Mueller-Töwe, 2006) or Teleosaurus ( Jouve, 2009) .

The posterolateral process of the parietal articulates with the squamosal laterally and the otoccipital posteriorly. At the junction of the posterolateral processes, the parietal would have articulated with the supraoccipital, a small portion of which may be preserved, though its suture with the parietal is unclear. The parietal contributes to the occipital surface, though the medial portion is missing. The parietal occipital surface is slightly sloped posteroventrally, differing from the more vertical orientation of the squamosal occipital surface.

Postorbital —The posterior portion of the right postorbital is preserved in articulation with the squamosal ( Figs. 2 , 3 ). The preserved portion is dorsoventrally tall and mediolaterally narrow. Its lateral surface is ornamented with distinct pits, some of which are elongated longitudinally into short grooves. The presence of ornamentation on the lateral temporal bar is uncommon among thalattosuchians, but is shared with Pelagosaurus (NHMUK PV OR 32599; Mueller-Töwe, 2006), Platysuchus multiscrobiculatus (SMNS 9930; Mueller-Töwe, 2006), and to a lesser extent Plagiophthalmosuchus gracilirostris (NHMUK PV R 757). An anteroposteriorly directed ridge runs near the ventral margin of the bone, separating a narrow unornamented flange from the ornamented area above similar to Pelagosaurus typus (NHMUK PV OR 32599).

The postorbital articulates posteriorly with the squamosal at a v-shaped suture, with an anterior projection of the squamosal dividing the posterior margin of the postorbital into two posterior processes, as in most thalattosuchians (e.g., Teleosaurus cadomensis [ Jouve, 2009]; Indinosuchus potamosiamensis [ Martin et al., 2019]; Pelagosaurus [NHMUK PV OR 32599]). The dorsal process is much larger than the ventral process and articulates only with the squamosal. The ventral process is narrower, and articulates with the squamosal and the dorsolateral process of the quadrate, anterior to the external acoustic meatus. The dorsal surface of the postorbital narrows to a ridge, continuous with the dorsal surface of the squamosal (postorbital-squamosal ridge sensu Young et al., 2013).

Squamosal —The right squamosal is nearly complete ( Figs. 2 , 3 ). The bone is v-shaped, with its anterior and medial processes forming an acute angle (∼60°) similar to Pelagosaurus typus (NHMUK PV OR 32599), Opisuchus meieri ( Aiglstorfer et al., 2020) , and Plagiophthalmosuchus gracilirostris (NHMUK PV OR 15500), but differing from the condition in many teleosaurids (e.g., Teleosaurus [ Jouve, 2009]; Indosinosuchus [ Martin et al., 2019]; Macrospondylus [ Wilberg et al., 2022]) and most metriorhynchids (e.g., Torvoneustes [ Young et al., 2013]; and Purranisaurus [ Herrera et al., 2015]) where the angle is closer to 90°. It articulates anteriorly and laterally with the postorbital, ventrally with the quadrate, posteriorly with the otoccipital and medially with the parietal. The supratemporal fossa extends posterolaterally along the squamosal, forming narrow, elevated ridges along the dorsal surface of the anterior and medial processes. The squamosal articulates with the parietal dorsal to the temporo-orbital foramen, just medial to its lateral border. The squamosal forms the lateral and ventrolateral borders of the temporo-orbital foramen, and contributes slightly to the dorsal border. It is unclear whether the process of the squamosal forming the ventrolateral border of the temporo-orbital foramen would have contacted the prootic medially (excluding the quadrate from the margin of the opening) as in most metriorhynchoids and some teleosauroids (e.g., Macrospondylus bollensis [MCZ PVRA-1063]; Wilberg et al., 2022), or whether the quadrate would have contributed to the ventral margin as in Teleosaurus ( Jouve, 2009) and Indosinosuchus ( Martin et al., 2019) .

The lateral surface of the anterior process of the squamosal is ornamented with closely spaced deep pits, similar to the postorbital. The posterolateral surface is smooth and gently concave, forming a shallow trapezoidal squamosal fossa (sensu Wilberg et al., 2022), although the ventral-most portion is missing. The shape of the fossa is similar to Pelagosaurus (NHMUK PV OR 32599), but differs from the dorsoventrally elongate fossa of Macrospondylus bollensis (MCZ PVRA-1063; Wilberg et al., 2022). Unlike other known thalattosuchians, the squamosal fossa of LYMPH 2021/45 appears to be directed slightly ventrally, rather than dorsally. The squamosal fossa lies posterodorsal to the external otic aperture.

The occipital surface of the medial process of the squamosal is dorsoventrally taller than other known thalattosuchians and articulates ventrally with the paroccipital process of the otoccipital and medially with the occipital surface of the parietal. The occipital surface of the squamosal is approximately twice the dorsoventral height of the distal end of the paroccipital process, though the sutures in this region are difficult to make out.

Quadrate —Most of the right quadrate is preserved ( Figs. 2 , 3 ), lacking only the lateral hemicondyle. However, sutures with the surrounding bones are difficult to delineate and artifacts in the scan obscure detail in the otic region. The quadrate articulates with the squamosal anterodorsally, the otoccipital posterodorsally, the prootic anteromedially, the basisphenoid and pterygoid ventromedially. The quadrate body is inclined posteroventrally, positioning the medial hemicondyle ventral to the occipital condyle, approximately in line with the ventral margin of the basal tubera as in Pelagosaurus (NHMUK PV OR 32599; Mueller-Töwe, 2006). Its posterodorsal surface is broadly overlapped by the ventrolateral process of the otoccipital. The medial hemicondyle is ventromedially inclined, with its main axis oriented approximately 45° from horizontal. The ventral surface of the quadrate body is either damaged anterior to the medial hemicondyle, or artifacts in the scan prevent segmenting of its ventral surface.

The dorsolateral process of the quadrate is preserved, but the presence of several highly absorbing objects in the scan makes this region difficult to interpret due to beam hardening artifacts. As in other thalattosuchians, the quadrate articulates with the ventral surface of the squamosal, sending a thin otic lamina posteriorly to form the roof of the external otic aperture, excluding the squamosal from its margin. The dorsolateral process potentially articulated with the posteroventral surface of the postorbital, but as the sutures in this region are unclear, this cannot be confirmed.

The dorsal primary head of the quadrate contacts the lateral wall of the braincase, but these articulations appear narrower than in other thalattosuchians or crocodyliforms. Anteromedially, it is sutured to the ventral margin of the medial process of the squamosal and has an anteroventrally sloping suture with the prootic, contributing to the posteroventral wall of the supratemporal fossa. This contact with the prootic is shorter than in other thalattosuchians, where the quadrate extends anteriorly along the prootic to reach or nearly reach the trigeminal foramen. In Turnersuchus , the quadrate is broadly separated from the trigeminal foramen by the prootic and basisphenoid, unlike crocodyliforms generally ( Clark, 1994).

The pterygoid process of the quadrate has a short, obliquely oriented suture with the posterolateral lamina (quadrate process) of the pterygoid. Extending anteriorly is a short, squared orbital process. The orbital process of Turnersuchus is similar in shape to Pelagosaurus , but oriented more ventrally along the braincase. The orbital process primarily articulates with the pterygoid and basisphenoid (reminiscent of Sphenosuchus acutus [ Walker, 1990], but with a very different pterygoid morphology). This differs from other thalattosuchians in which the orbital process is more anteriorly oriented, articulating with the laterosphenoid in addition to the pterygoid and basisphenoid (e.g., Macrospondylus ; Wilberg et al., 2022). As in other thalattosuchians (e.g., Pelagosaurus [NHMUK PV OR 32599]; Plagiophthalmosuchus cf. gracilirostris [NHMUK PV OR 33095; Brusatte et al., 2016]; Cricosaurus araucanensis [ Herrera et al., 2018]; Metriorhynchus cf. westermani [ Fernández et al., 2011]; Macrospondylus bollensis [MCZ VPRA-1063]; Machimosaurus buffetauti [SMNS 91415]; Teleosaurus cadomensis [ Jouve, 2009]), the orbital process lacks bony attachment to the pterygoid, basisphenoid, or laterosphenoid anteromedially. The short length and more ventral orientation of the orbital process of the quadrate in Turnersuchus results in a very broad separation from the laterosphenoid.

Laterosphenoid —The posterior portion of the right laterosphenoid is preserved ( Figs. 2 , 3 ). It articulates with the frontal anterodorsally, the parietal posterodorsally, the prootic posteriorly, and the basisphenoid ventrally. The laterosphenoid has been slightly displaced from the adjacent bones. Because the laterosphenoid is not preserved in articulation with the prootic, it is unclear whether this suture formed a raised ridge dorsal to the trigeminal foramen as in most thalattosuchians (e.g., Pelagosaurus [NHMUK PV OR 32599]; Plagiophthalmosuchus cf. gracilirostris [NHMUK PV OR 33095; Brusatte et al., 2016]; Suchodus brachyrhynchus [NUMHK PV R 3700]). When a ridge is present, it divides the supratemporal fossa into posterior and anterior fossae interpreted as the insertions for M. adductor mandibulae externus profundus and M. pseudotemporalis superficialis, respectively ( Holliday & Witmer, 2009). The lateral surface of the preserved portion is vertical, becoming somewhat ventrolaterally oriented anteriorly. The laterosphenoid forms the anterior margin of the trigeminal foramen.

Prootic —The right prootic is nearly complete ( Figs. 2 , 3 ). It is triangular in dorsal view and broadly exposed as in other thalattosuchians and non-crocodyliform crocodylomorphs ( Clark, 1994). It articulates with the laterosphenoid anteriorly (though these bones have been slightly displaced), the parietal dorsally and posteriorly, the basisphenoid ventrally, and the quadrate posterolaterally. A small, dorsally directed peg is present along its suture with the parietal. Acorresponding shallow notch on the lateral surface of the parietal intertemporal bar would have articulated with this peg. This dorsal prootic peg appears autapomorphic for LYMPH 2021/45. The prootic forms the ventral margin of the temporo-orbital foramen and potentially contacts the squamosal in this region. It forms the dorsal, posterior, and ventral margins of the dorsoventrally elongate trigeminal foramen. The dorsoventral elongation of the trigeminal foramen is similar to Pelagosaurus (NHMUK PV OR 32599; Holliday & Witmer, 2009), though Turnersuchus lacks the distinct constriction near the midpoint demarcating exit points for the root of the trigeminal and the rostral middle cerebral vein ( Herrera, 2015). This shape differs from Plagiophthalmosuchus cf. gracilirostris ( Brusatte et al., 2016) and most teleosauroids in which the foramen is more circular. In lateral view a broad lamina projects ventrally, immediately posterior to the trigeminal foramen (and forming its posterior border). This ventral lamina contacts the laterosphenoid anteroventrally and the basisphenoid posteroventrally, near the dorsal margin of the orbital process of the quadrate. This appears similar to the morphology of Pelagosaurus (BRLSI M1413; visible in the CT model by Ballell et al., 2019), where this broad process divides the trigeminal foramen from a lateral communication with the paratympanic sinus. However, it differs from the narrow lamina present in the teleosauroids Macrospondylus bollensis (MCZ PVRA- 1063), Machimosaurus buffetauti (SMNS 91415), and Proexochokefalos heberti (MNHN 1890-13; Wilberg et al., 2022).

Otoccipital —The opisthotic and exoccipital are fused into a single otoccipital. Much of the right otoccipital is preserved, though its sutures with the quadrate, squamosal, and parietal are difficult to discern in the CT data ( Figs. 2 , 3 ). It articulates with the parietal dorsally, the squamosal dorsolaterally, the quadrate ventrolaterally, and the basioccipital and basisphenoid ventromedially. It forms the ventrolateral, lateral, and dorsolateral margin of the foramen magnum. The dorsal margin is incomplete, so it is not clear whether it contacted the left otoccipital dorsal to the foramen magnum, or whether the supraoccipital interposed between them.

The paroccipital process is well developed, and extends laterally to the lateral margin of the occipital surface. It is relatively vertical across its occipital surface, with its lateral half becoming slightly posteroventrally sloped. This lateral terminus ends just inferior to the broken inferior surface of the squamosal fossa. In other thalattosuchians (e.g., Macrospondylus bollensis [MCZ VPRA-1063; Wilberg et al., 2022]; Pelagosaurus typus [NHMUK PV OR 32599]; Torvoneustes coryphaeus [ Young et al., 2013]), the lateral tip of the paroccipital process articulates with a concavity on the squamosal adjacent to the squamosal fossa. It is possible a similar configuration was present in LYMPH 2021/45, but damage to the squamosal fossa makes this uncertain.

Like other thalattosuchians, Turnersuchus possesses a broad ventrolateral flange of the otoccipital that broadly covers the dorsal surface of the quadrate body. Abroad ventrolateral flange of the otoccipital is also present in protosuchids, though less developed than in thalattosuchians ( Clark, 1994; Pol & Gasparini, 2009). Laterally, the ventrolateral flange ends slightly medial to the lateral end of the paroccipital process similar to Cricosaurus araucanensis ( Herrera et al., 2018) . This differs from Pelagosaurus (NHMUK PV OR 32599), Macrospondylus bollensis (MCZ VPRA-1063), and Cricosaurus rauhuti (SNSBBSPG 1973 I 195; Herrera et al., 2021) in which the ventrolateral flange exceeds the paroccipital process laterally.

Typically, a number of foramina pierce the otoccipital. No canals were traceable on the scan, but some of the foramina are apparent as depressions on the occipital surface. A depression lateral to the occipital condyle and approximately in line with the floor of the foramen magnum likely represents the hypoglossal foramen. Ashort distance ventrolaterally, near the articulation with the basioccipital tuber lies a circular depression potentially representing the internal carotid foramen. Unfortunately, given the preservation, it is difficult to determine whether it is enlarged as in other thalattosuchians. Located lateral to the hypoglossal foramen, around the mediolateral midpoint of the paroccipital process lies an ovate depression we interpret as the vagus foramen. The posteroventrally sloped portion of the paroccipital process overhangs this foramen. The locations of these foramina are consistent with those of other thalattosuchians (e.g., Pelagosaurus [NHMUK PV OR 32599]; Plagiophthalmosuchus cf. gracilirostris [ Brusatte et al., 2016]; Macrospondylus [ Wilberg et al., 2022]; Teleosaurus [ Jouve, 2009]). Ashort distance lateral to the vagus foramen lies a laterally open notch between the paroccipital and ventrolateral processes of the otoccipital. This represents the cranioquadrate canal. As preserved, it is open laterally, though the squamosal and quadrate, which would likely have formed the lateral border if it existed, are damaged in this area. The cranioquadrate canal is fully enclosed (e.g., Machimosaurus buffetauti [SMNS 91415]; Macrospondylus bollensis [MCZ VPRA-1063]), or very nearly enclosed (e.g., Teleosaurus cadomensis [MNHN AC 8746; Jouve, 2009]), in all other thalattosuchians in which this region is preserved.

Basisphenoid —The basisphenoid is partially preserved, lacking its anterior region and rostrum ( Figs. 2 , 3 ). It articulates anteroventrally with the pterygoid, posteriorly with the basioccipital and dorsally with the prootic and laterosphenoid (though these latter two bones have been displaced). Only a small portion of its lateral surface is exposed, and the remainder of the description of this bone comes from the digital preparation. In ventral view, the basisphenoid is triangular in shape, with the anterior apex extending anteriorly between the quadrate processes of the pterygoid. The ventral exposure is slightly wider (mediolaterally) than long (anteroposteriorly). Posteriorly, the basisphenoid articulates with the basioccipital and forms the anterior half of the ovate opening for the median pharyngeal tube (=median Eustachian tube; Colbert, 1946). Thin lateral processes of the basisphenoid project posterolaterally, separating the quadrate from the basioccipital. The median pharyngeal foramen is rather large relative to that of other thalattosuchians, opening into a bulbous cavity within the basisphenoid which then divides laterally similar to the sphenosuchian Almadasuchus ( Leardi et al., 2020) . However, these diverticula cannot be traced further with any detail.

Basioccipital —The basioccipital is nearly complete, lacking only the lateral side of the left basal tuber ( Figs. 2 , 3 ). It has not been mechanically prepared, but has been digitally prepared. The occipital condyle is ovoid, mediolaterally wider than tall. The basioccipital articulates with the otoccipital dorsolaterally and the basisphenoid anteriorly. The occipital condyle appears to be smaller than the foramen magnum (though the incomplete preservation of the foramen magnum prevents confirmation of this comparison). This is small relative to other thalattosuchians, but similar to the proportions of many sphenosuchians (e.g., Junggarsuchus [ Ruebenstahl et al., 2022]; Dibothrosuchus [ Wu & Chatterjee, 1993]; and Sphenosuchus [ Walker, 1990] and protosuchids (e.g., Protosuchus richardsoni [UCMP 131827; Clark, 1986] and Eopneumatosuchus colberti [ Melstrom et al., 2022]). The occipital condyle is approximately the same size as the foramen magnum in some thalattosuchians (e.g., Pelagosaurus typus [NHMUK PV OR 32599] and Teleosaurus cadomensis [MNHN AC 8746; Jouve, 2009]). However, it is notably larger than the foramen magnum in most thalattosuchians (e.g., Plagiophthalmosuchus cf. gracilirostris [NHMUK PV OR 33095; Brusatte et al., 2016]; and Macrospondylus bollensis [MCZ VPRA- 1063; Wilberg et al., 2022]). Ventrolateral to the occipital condyle are small, weakly developed basioccipital tubera. The tubera are mediolaterally wider than tall and are rather small relative to other thalattosuchians.

In ventral view, the basioccipital has a gently curved suture with the posterior surface of the basisphenoid. Interrupting this articulation along the midline is the median pharyngeal foramen, of which the basioccipital forms the posterior margin. Immediately posterior to the median pharyngeal foramen lies a deep fossa, interposed between the basal tubera. Poor contrast in the CT scan makes the lateral articulation between the basioccipital with the lateral wings of the basisphenoid and ventromedial portion of the otoccipital difficult to discern. However, it appears that the basioccipital forms a short portion of the medial border of the lateral Eustachian foramen, similar to Macrospondylus bollensis (MCZ VPRA-1063; Wilberg et al., 2022) and Pelagosaurus typus (NHMUK PV OR 32599).

Pterygoid —The posterior portion of the pterygoids are preserved and right and left sides appear fused ( Figs. 2 , 3 ). The preserved portion includes the posterior margin of the internal choana and part of the left pterygoid wing (flange). Posteriorly and dorsally, the pterygoid articulates with the basisphenoid. Posterolaterally, the pterygoid has a short articulation with the quadrate. As in other thalattosuchians, the pterygoid lacks a dorsal extension and contacts neither the laterosphenoid nor the trigeminal foramen. In ventral view the basisphenoid projects anteriorly like a wedge, dividing two slender, posterolateral laminae of the pterygoid. These posterolateral laminae lie between the basisphenoid medially and the pterygoid process of the quadrate laterally. At the juncture of these posterolateral laminae (at the apex of the basisphenoid ventral exposure), the posterior margin of the pterygoid possesses a relatively deep, but anteroposteriorly short concavity projecting towards the choana.

The lateral wing is short, laminar, and tapers laterally. It is inclined slightly posteroventrally. It lacks a thickened, vertically oriented flat lateral surface (torus transiliens). This structure is typically smaller in thalattosuchians than in crocodyliforms, but its total absence is surprising. This portion of the pterygoid is embedded in matrix and, while the edges of the element appear relatively clean in the digital model, it is possible that this structure is broken. Posterior to the lateral wing, the lateral margin of the pterygoid is strongly concave.

Mandible

General Comments —The posterior regions of both mandibular rami are preserved, including right (block 1; Figs. 1 , 4 ) and left (block 3; Fig. 5 ) retroarticular processes. Additional smaller fragments preserve parts of the dentary and angular.

Dentary —The anterior portion of the right dentary is preserved, including part of the dentary symphysis and four alveoli containing heavily weathered teeth ( Fig. 6A, B ). We interpret these as the second through fifth alveoli (D2–D5). The D3 and D4 alveoli are enlarged relative to D2 and D5. They appear confluent (though it is possible that a narrow interalveolar septum is present, but not exposed) and are positioned on a slight lateral expansion of the dentary, giving it a somewhat spatulate shape and are slightly dorsal in position relative to D2 and D5. D3 and D4 are also typically the largest of the anterior dentary teeth in most other thalattosuchians, also with alveoli that are confluent or have a very narrow interalveolar space (e.g., Pelagosaurus typus [BRLSI M1413; Pierce and Benton, 2006]; Macrospondylus bollensis [NHMUK PV R 12011]; Proexochokefalos heberti [MNHN 1890-13]; Lemmysuchus obtusidens [NHMUK PV R 3168; Johnson et al., 2017]; Thalattosuchus superciliosus [NHMUK PV OR 46323]). The symphysial surface preserves a series of grooves radiating anteriorly and posteriorly from the Meckelian fossa, located medial to the D5 alveolus and extending posteriorly to the broken posterior end of the specimen. This would have formed a typical Class III mandibular symphysis (sensu Scapino, 1981), shared by other thalattosuchians and most crocodyliforms ( Holliday & Nesbitt, 2013).

Asecond small fragment of the left dentary is preserved ( Fig. 6C, D ). This portion comes from the posterior region of the dentary, potentially posterior to the symphysis. Its lateral surface is ornamented with deep grooves ventrally, which become less distinct dorsally. Four teeth are preserved, though mediolaterally crushed. Just medial to the toothrow, the medial shelf of the dentary possesses an elongate groove, paralleling the toothrow. This groove was likely for articulation of the anterior process of the coronoid, which in thalattosuchians is highly elongate and abuts the posterior portion of the toothrow. An anteriorly elongate coronoid is also present in most sphenosuchians ( Ruebenstahl et al., 2022), though in these taxa the anterior process extends along most of the dentary toothrow. Medially this fragment of the dentary would have articulated with the splenial, but no trace of this element is preserved.

A third mandibular fragment potentially preserves the posterolateral surface of the left dentary articulating with a small fragment of the angular ( Fig. 6E ). The lateral surface of this dentary fragment is ornamented by fine anteroposteriorly directed striations and bears an elongate groove spanning its preserved length. This groove lies dorsal to the dentaryangular articulation and is not quite parallel with this suture, diverging anteriorly. This groove is likely a small portion of the surangulodentary groove (sensu Young et al., 2012) common among thalattosuchians, though it is not as deeply excavated as in metriorhynchids.

Surangular —The posterior portions of both right and left surangulars are preserved ( Figs. 4 , 5 ). On the right side, the posterior-most portion of the surangular is preserved on the lateral surface of the retroarticular process. The preserved portion has a horizontal suture with the angular ventrally and articulates with the articular medially. Its surface is marked with distinct pits anteriorly that become less distinct posteriorly, such that the posterior-most portion is smooth. It nearly reaches the posterior end of the retroarticular process. The left surangular is exposed in medial view, anterior to the glenoid fossa. It is gently concave, articulating with the angular ventrally. Near the anterior end of the preserved portion lies a circular foramen on the medial surface, located near the dorsoventral midpoint of this surface. Asimilar foramen is present in Pelagosaurus (NHMUK PV OR 32599), but that of T. hingleyae is more anteriorly positioned.

Angular —The posterior portion of each angular is preserved ( Figs. 4 , 5 ), as well as a small, more anterior fragment of the left angular articulating with the dentary described above ( Fig. 6E ). The lateral surface of the small fragment articulating with the dentary is ornamented with strong, anteroposteriorly aligned grooves. The preserved posterior parts of the angular are ornamented with distinct pits. These pits begin to dissipate posteriorly, beginning at the level of the glenoid fossa, becoming smooth approximately half way along the length of the retroarticular process. The angular articulates with the dentary anteriorly, the articular and prearticular medially, and the surangular dorsally. The ventral edge of the articular forms a medially curved shelf, in which the prearticular and articular sit. Posteriorly it extends nearly to the tip of the retroarticular process.

Prearticular —A prearticular bone is present as in other thalattosuchians ( Figs. 4 , 5 ). It is an elongate triangular bone articulating with the articular dorsally and the angular laterally and ventrally. Posteriorly it extends approximately two thirds the length of the retroarticular process. Its anterior extent is unknown as it is damaged on both sides.

Articular —Both right and left articulars are nearly complete. The left is exposed in ventral view ( Fig. 5 ), while the right is partially visible in lateral view ( Fig. 1 ). The right articular has been digitally segmented so all portions can be described ( Fig. 4 ). The articular articulates with the surangular and angular laterally, and the prearticular ventrally. The articular forms the rectangular glenoid fossa and the triangular retroarticular process. The medial surface of the articular is concave, with the medial shelf of the retroarticular process and medial half of the glenoid fossa overhanging its surface. The glenoid fossa consists of medial and lateral concavities separated by a subtle ridge. The medial portion of the fossa extends slightly further ventrally, to articulate with the dorsoventrally deeper medial hemicondyle of the quadrate. The glenoid fossa is bordered anteriorly by a low, straight, transversely oriented ridge and posteriorly by a strong sigmoid ridge. Laterally, the glenoid may have been bordered by the surangular. This region is damaged, but it does not appear that the surangular would have contributed to the articular surface.

The retroarticular process is triangular in dorsal view with its length slightly exceeding the width of the glenoid fossa. The retroarticular process of Turnersuchus is considerably shorter than that of most teleosauroids (e.g., Plagiophthalmosuchus gracilirostris [NHMUK PV OR 15500]; Mycterosuchus nasatus [NHMUK PV R 2617; Andrews, 1913]; Macrospondylus bollensis [MCZ VPRA-1063; Wilberg et al., 2022]; Indosinosuchus potamosiamensis [PRC-11; Martin et al., 2019]), and more closely resembles the morphology of basally branching metriorhynchoids (e.g., Pelagosaurus [BRLSI M1413; Pierce and Benton, 2006]; Teleidosaurus calvadosii [NHMUK PV R 2681]; Zoneait nargorum [UOMNH F39539; Wilberg, 2015a]). The dorsal surface of the retroarticular process houses a broad fossa for the attachment of M. depressor mandibulae. In most thalattosuchians, a long crest divides the dorsal surface into medial and lateral fossae (e.g., Pelagosaurus [BRLSI M1413; Pierce & Benton, 2006]; Teleidosaurus calvadosii [NHMUK PV R 2681]; Macrospondylus bollensis [MCZ VPRA-1063; Wilberg et al., 2022]). In Turnersuchus , a faint crest begins along the posterior margin of the glenoid, but flattens out about one third the length of the fossa. The posterior end of the articular is ovate and convex, slightly exceeding the posterior end of the surangular and angular.

Axial Skeleton

General Comments —The vertebral column of Turnersuchus hingleyae is not completely preserved. Block 1, which was CTscanned, includes the last five cervical and the first five dorsal vertebrae which are preserved in articulation, plus one isolated cervical vertebra. Additionally, four articulated dorsal vertebrae are preserved in block 2, which represent more posterior vertebrae and are not continuous with the series preserved in block 1. Sacral vertebrae are not preserved and only eight caudal vertebrae are present, preserved as four isolated pairs of vertebrae, two of which are preserved in blocks 4 and 5. In total, 23 vertebrae are preserved: six cervical vertebrae, nine dorsal vertebrae, and eight caudal vertebrae. CT data were obtained for all cervical vertebrae and five of the dorsal vertebrae. All vertebrae of T. hingleyae are amphicoelous, as is typical for most non-eusuchian crocodylomorphs.

Cervical Vertebrae and Ribs —The last five cervical vertebrae are preserved in articulation in block 1, with their right side exposed ( Fig. 1 ). Additionally, there is an isolated cervical vertebra in the same block, which was probably originally located anterior to these five articulated vertebrae (i.e., between the atlas-axis and the last five cervical vertebrae) and has the dorsal surface of its centrum exposed. The cylindrical centra are slightly anteroposteriorly longer than dorsoventrally high. The anterior and posterior articular surfaces are slightly concave. In more anterior vertebrae, these articular surfaces are slightly higher than wide, whereas in more posterior ones the centra are nearly as high as wide, forming a more circular surface ( Fig. 7A–E ). In ventral view, cervical centra are roughly hourglass-shaped, due to the thick margins of the anterior and posterior articular surfaces of the centra ( Fig. 7E ). As in all thalattosuchians, cervical or dorsal vertebrae do not bear distinctive hypapophyses. The ventral surface of the cervical centra of Turnersuchus hingleyae exhibits a ventral keel ranging anteroposteriorly through the midline the vertebrae ( Fig. 7E ), similar to the condition seen in other thalattosuchians, such as Indosinosuchus potamosiamensis (PRC-18; Martin et al. 2019), Enaliosuchus macrospondylus (MB.R.1943.3; Sachs et al. 2020) and Pelagosaurus typus (BSGP 1890 I 510/1).

The cervical transverse processes, or diapophyses, and parapophyses of Turnersuchus hingleyae bear the facets for the attachment of the cervical ribs (tuberculum and capitulum). The parapophyses are located anteroventrally on the centrum, and project ventrolaterally ( Fig. 7A, B ). The diapophyses project from around anteroposterior midpoint of each vertebra, originating on the lateral surface of the neural arch base, and from slightly more dorsally in the last cervical vertebra (a pattern also observed in other thalattosuchians, including teleosauroids and metriorhynchoids; Wilkinson et al., 2008). The diapophyses are strongly inclined ventrolaterally, although slightly less so in the final cervical vertebra ( Fig. 7A, B ). All five articulated cervical vertebrae preserve the neural arches. Additionally, the isolated cervical vertebra also preserves part of its left neural arch.

The prezygapophyses and postzygapophyses of the cervical vertebrae are at the same height, dorsal to the neural arches ( Fig. 7A–E ). Prezygapophyses are anterodorsally oriented in lateral view ( Fig. 7C ) and the articular facets face dorsomedially at an angle of nearly 45°, as in other thalattosuchians, such as Pelagosaurus typus (BRLSI M3578; Pierce & Benton, 2006), Enaliosuchus macrospondylus (MB.R.1943.6; Sachs et al., 2020), and Charitomenosuchus leedsi (NHMUK PV R 3806; Andrews, 1913). The prezygapophyses of more posterior cervical vertebrae do not differ much, in shape or orientation, from the anterior ones. Postzygapophyses are slightly larger than prezygapophyses, but also do not differ much from more anterior to more posterior cervical vertebrae. Postzygapophyses exhibit suprapostzygapophyseal laminae (sensu Pol, 2005) on their dorsal surfaces, as in other crocodylomorphs, such as the notosuchians Notosuchus terrestris (MACN-RN 1037; Pol, 2005) and Araripesuchus tsangatsangana (FMNH PR 2297; Turner, 2006), but also observed in thalattosuchians, such as in Torvoneustes carpenteri (BRSMG Cd7203; Wilkinson et al., 2008) and Teleidosaurus calvadosii (MPV 20120.3.45; Hua, 2020). Both suprapostzygapophyseal laminae join each other medially, forming the neural spine dorsally. All five articulated cervical vertebrae have their neural spine completely preserved, although in the last three vertebrae the dorsal-most tips of the neural spine are displaced from their original position ( Fig. 7A–E ). All five neural spines are rounded dorsally and are slightly shorter dorsoventrally than the dorsoventral height of the centrum. Neural spines of more posterior cervical vertebrae appear to be proportionally longer anteroposteriorly than more anterior ones, although they are broken dorsally, preventing accurate assessment.

The five articulated cervical vertebrae also preserve their right cervical ribs ( Fig. 7A–E ). The ribs are not attached to the vertebrae, but are preserved only slightly displaced from their original positions. The ribs are “double-headed” and exhibit a typical crocodylomorph morphology of postaxial cervical ribs ( Mook, 1921). The first four ribs of the series are very similar in shape to each other, with a mediolaterally flattened shaft extending parallel to the longitudinal axis of the vertebral column, and a pair of processes, tuberculum and capitulum, that attach to the diapophysis and parapophysis, respectively. The shaft of these four ribs bears anterior and posterior processes, with the posterior being more elongated. In these ribs, the tuberculum and capitulum project distally from their attachment with diapophysis and parapophysis, making them perpendicular to the shaft of the ribs. The tuberculum is slightly longer than the capitulum, whereas the capitulum is more anteriorly positioned, so that the two processes are not exactly in parallel. The first three ribs of the series are nearly completely preserved, whereas the fourth lacks the anterior- and posterior-most processes of the shaft. The last cervical rib is comparatively more elongated than the other four, although not as long as the dorsal ribs. In this last cervical rib, tuberculum and capitulum are not perpendicular to the shaft, but rather look like direct extensions of the shaft, projecting posteriorly from the diapophysis and parapophysis.

Dorsal Vertebrae and Ribs —The first five dorsal vertebrae are preserved in articulation in block 1, with their right and ventral surfaces mostly exposed ( Fig. 1 ). There are also four dorsal vertebrae preserved in articulation in block 2 ( Fig. 8 ), the exact position of which in the vertebral column cannot be verified, but were probably only slightly posterior to the vertebral series preserved in block 1. We will focus our description of the dorsal vertebrae on the ones preserved in block 1 ( Fig. 7F–J ), given that these were CT-scanned, but the vertebrae in block 2 will be mentioned when appropriate.

Only the first three vertebrae of the series in block 1 preserve their centra, which are missing in the last two vertebrae of the series. Similar to the cervical vertebrae, the cylindrical centra of dorsal vertebrae of Turnersuchus hingleyae are anteroposteriorly longer than dorsoventrally high, with more posterior vertebrae becoming even longer anteroposteriorly (a pattern confirmed in the vertebrae preserved in block 2), as also seen in Indosinosuchus potamosiamensis (PRC-20 and PRC-21; Martin et al. 2019), Enaliosuchus macrospondylus (MB.R.1943.6; Sachs et al. 2020), Charitomenosuchus leedsi (NHMUK PV R 3806; Andrews, 1913) and Cricosaurus araucanensis (MLP 72-IV-7-1; Herrera et al. 2013). The concave anterior and posterior articular surfaces of the centra are similar to the ones observed in the posteriormost cervical vertebrae, with roughly circular surfaces, nearly as high as wide ( Fig. 7H ). The centra exhibit an hourglass shape in ventral view, as a consequence of the thicker margins of the anterior and posterior articular surfaces, similar to the cervical centra ( Fig. 7J ). However, in the first two dorsal vertebrae, the parapophyses project from a level ventral to the neural arches and are located near the anterior articular surface, which gives these two vertebrae laterally expanded anterior halves of the centra in ventral view. The dorsal vertebrae of T. hingleyae lack the clear ventral keel seen in cervical centra, a condition also observed in Magyarosuchus fitosi (MTM V.97.26; Osi et al., 2018), Indosinosuchus potamosiamensis (RMH uncataloged; Martin et al. 2019) and Enaliosuchus macrospondylus ( Sachs et al. 2020) .

The parapophyses of the first two dorsal vertebrae of Turnersuchus hingleyae are more ventrally located (i.e., placed on the centra) than those of more posterior vertebrae, in which the parapophyses project laterally from the same level of the neural arches, more closely located to the transverse processes ( Fig. 7G, H ). The transverse processes of the first two vertebrae are nearly cylindrical and project laterally from the neural arches, whereas those of the remaining dorsal vertebrae become increasingly more inclined dorsally and anterodorsally flat. Similar to the cervical vertebrae, the parapophyses of dorsal vertebrae are located near the anterior margin of the centra in lateral view, whereas the transverse processes are placed near the middle of the anteroposterior extension of the centra. This is similar to the condition of Enaliosuchus macrospondylus ( Sachs et al., 2020) and Magyarosuchus fitosi (MTM V.97.26.; Osi et al., 2018), but different from what is seen in Charitomenosuchus leedsi (NHMUK PV R 3806; Andrews, 1913), in which the parapophyses are not as anteriorly located, particularly in more anterior dorsal vertebrae.

The neural arches are present in the first three vertebrae of the series and also partially preserved in the two remaining vertebrae. Nevertheless, the preservation of the region of the neural arches is not ideal, particularly in more posterior vertebrae, preventing a clear assessment of the morphology of the neural spines. In more anterior dorsal vertebrae, the prezygapophyses and postzygapophyses are better preserved and located dorsal to the neural arches in lateral view ( Fig. 7G, I ). In comparison to the prezygapophyses of cervical vertebrae, those of dorsal vertebrae have their articular facets more inclined and slightly more turned medially.

The first three dorsal vertebrae in block 1 preserve the proximal portions of their associated ribs nearly in articulation, whereas three other partial dorsal ribs are also preserved in the block but not in articulation. Some dorsal vertebrae and gastralia are also preserved in block 2 ( Fig. 8 ). The first three dorsal ribs of Turnersuchus hingleyae exhibit a proximal morphology similar to that of other crocodylomorphs ( Mook, 1921), with the capitulum longer than the tuberculum. The tuberculum is parallel with the axis of the rib shaft, whereas the capitulum forms an angle of nearly 45° with the shaft. The third rib is better preserved, exhibiting a long and slightly curved shaft that projects posteriorly at least to the level of the fifth dorsal vertebra.

Caudal Vertebrae —Two pairs of caudal vertebral centra are partially preserved in blocks 4 and 5 ( Fig. 9A, B ). Additionally, two other pairs of vertebral centra are present ( Fig. 9C, D ), which are probably caudal vertebrae, but the poor preservation prevents an unambiguous assignment. Therefore, we focus our description of caudal vertebrae on the pairs preserved in blocks 4 and 5. After the submission of this work, an additional pair of partial vertebral centra associated with the holotype was donated to LYMPH and reposited under the same specimen number (LYMPH 2021/45). These elements provide no additional information beyond that of the other elements. Photographs of this material are available at www.morphobank.org/ permalink/?P4271.

Using Magyarosuchus fitosi (MTMV.97.28.; Osi et al., 2018) and Cricosaurus araucanensis (MLP 73-II-27-6; Herrera et al., 2013) as reference specimens (given the fairly complete description of their caudal series), the caudal vertebrae in these two blocks probably represent anterior (block 4) and posterior (block 5) caudal vertebrae. The anterior and posterior articular surfaces are concave and the ventral surface does not bear any ridge. As in other vertebrae of Turnersuchus hingleyae , the centra are anteroposteriorly longer than dorsoventrally high. The centra in block 5 exhibit the typical morphology of more posterior caudal vertebrae, with mediolaterally compressed lateral surfaces and strongly concave ventral surfaces, which gives the centra a more rectangular look in lateral view, similar to what is seen in Neosteneosaurus edwardsi (NHMUK PV R 3701; Andrews, 1913).

Appendicular Skeleton

Pectoral Girdle —The right coracoid and scapula are preserved in articulation in block 1, with their lateral surfaces exposed ( Fig. 10 ). The coracoid preserves only its proximal end, lacking the shaft and distal portion, whereas the scapula is almost completely preserved, but broken. The bones are larger and longer than those of some metriorhynchids, such as Cricosaurus araucanensis (MLP 72-IV-7-1; Herrera et al. 2013), in which the pectoral girdle and forelimb bones are extremely reduced in size. The proximal portion of the coracoid is similar to that of Magyarosuchus fitosi (MTM V.97.7.; Osi et al., 2018) and Charitomenosuchus leedsi (NHMUK PV R 3806; Andrews, 1913), with its lateral surface bearing an oval-shaped coracoid foramen and its posterodorsal corner bearing a nearly flat surface that contributes to the glenoid fossa. The scapula of Turnersuchus hingleyae is relatively flat, with expanded and nearly equally wide distal and proximal ends (scapular blade and scapulocoracoid articulation, respectively), which gives it an almost bow-tie shape, similar to the scapulae of Pelagosaurus typus (BRLSI M3578; Pierce & Benton, 2006) and Macrospondylus bollensis (SMNS 51563; MuellerTöwe, 2006), but slightly different from the more rod-like shape of the scapula of Charitomenosuchus leedsi (NHMUK PV R 3806; Andrews, 1913). The anterior margin of the scapula of Turnersuchus is more strongly concave than is the posterior margin. This differs from the more symmetrical scapula of Pelagosaurus (BRLSI M1418; Pierce & Benton, 2006), but is shared with some teleosauroids (e.g., Indosinosuchus potamosiamensis [ Martin et al., 2019]; Lemmysuchus obtusidens [ Johnson et al., 2017]). The proximal most portion of the scapula is detached from the remainder of the bone, making the proximal end slightly displaced from the scapular shaft. Nevertheless, some features of the proximal end can still be observed, such as the faint deltoid crest. Both scapula and coracoid make a broad contact and contribute nearly equally in the glenoid fossa.

Forelimb —The proximal end of the right humerus is preserved in block 1, with its medial surface exposed and not in articulation with the pectoral girdle bones (indeed, the articulation surface is not preserved; Figs. 1 , 10 ). The humerus of Turnersuchus hingleyae is relatively flat and broad, with the preserved portion of the shaft nearly straight. The region is not ideally preserved, but the deltopectoral crest seems relatively small, similar to that of Zoneait nargorum (UOMNH F39539; Wilberg, 2015a) or Pelagosaurus (UH 4; Mueller-Töwe, 2006) which show a dorsoventrally thin and reduced crest, with probably less than one-third of the humerus length, but not as reduced as the crests of metriorhynchids (e.g., Cricosaurus araucanensis ; Herrera et al., 2013). The right ulna is preserved in block 2, lacking only its distal end and with its medial surface exposed ( Fig. 8 ). The proximal surface is twice as wide as the ulnar shaft. The ulna is not as strongly “J”-shaped as those of Zoneait nargorum (UOMNH F39539; Wilberg, 2015a) and Neosteneosaurus edwardsi (NHMUK PV R 3701; Andrews, 1913), due to a less developed olecranon process. Instead, the ulnar shaft of T. hingleyae is more curved than in these two taxa. Similar to Zoneait nargorum (UOMNH F39539; Wilberg, 2015a) and Neosteneosaurus edwardsi (NHMUK PV R 3701; Andrews, 1913), the ulna of T. hingleyae is reduced in size relative to the humerus (less than half of the humeral length), but proportionally larger than those of metriorhynchids (e.g., Cricosaurus araucanensis ; MLP 72-IV-7-1; Herrera et al., 2013).

Osteoderms

Only one dorsal osteoderm is preserved, in block 1 ( Figs. 1 , 10 ). It is oval-shaped, with a faint anteroposterior dorsal keel. Its shape and relatively small size suggest that it corresponds to a distal caudal osteoderm. Very few distal caudal osteoderms are reported for thalattosuchians, but the osteoderm of Turnersuchus hingleyae resembles one of the caudal osteoderms assigned to Charitomenosuchus leedsi (NHMUK PV R 3806; Andrews, 1913). It has a pitted ornamentation on its dorsal surface, with the pits being well separated from one another.

Figures

FIGURE 1. Preserved material of Turnersuchus hingleyae gen. et sp. nov. (LYMPH 2021/45) including five main blocks and isolated elements.

FIGURE 2. Skull of Turnersuchus hingleyae gen. et sp. nov. (LYMPH 2021/45). A, digital model in dorsal view; B, line interpretation of same; C, digital model in ventral view; D, line interpretation of same. Abbreviations: bo, basioccipital; bsp, basisphenoid; ch g, choanal groove; fr, frontal; lef, lateral Eustachian foramen; lsp, laterosphenoid; mpf, median pharyngeal foramen; occ, occipital condyle; oto, otoccipital; pa, parietal; po, postorbital; pro, prootic; pt, pterygoid; qu, quadrate; qu mhc, quadrate medial hemicondyle; qu op, quadrate orbital process; sq, squamosal; tof, temporo-orbital foramen.

FIGURE 3. Skull of Turnersuchus hingleyae gen. et sp. nov. (LYMPH 2021/45). A, digital model in ventrolateral view; B, line interpretation of same; C, digital model in occipital view; D, line interpretation of same. Abbreviations: bo, basioccipital; bo t, basioccipital tuberosity; bsp, basisphenoid; ch g, choanal groove; cqc, cranioquadrate canal; fm, foramen magnum; fr, frontal; icf, internal carotid foramen; lsp, laterosphenoid; mpf, median pharyngeal foramen; occ, occipital condyle; oto, otoccipital; pa, parietal; po, postorbital; pro, prootic; pro p, prootic peg; pt, pterygoid; pts com, communication with paratympanic sinus; qu, quadrate; qu mhc, quadrate medial hemicondyle; qu op, quadrate orbital process; sq, squamosal; sq f, squamosal fossa; V, trigeminal foramen; vf, vagus foramen; XII, hypoglossal foramen.

FIGURE 4. Right retroarticular process of Turnersuchus hingleyae gen. et sp. nov. (LYMPH 2021/45). A, digital model and line interpretation in lateral view; B, digital model and line interpretation in medial view; C, digital model and line interpretation in dorsal view. Abbreviations: an, angular; art, articular; gf, glenoid fossa; p art, prearticular; san, surangular.

FIGURE 5. Photograph and line interpretation of the posterior region of left mandibular ramus of Turnersuchus hingleyae gen. et sp. nov. (LYMPH 2021/45) exposed in ventral view. Abbreviations: an, angular; art, articular; p art, prearticular; san, surangular.

FIGURE 6. Mandibular fragments of Turnersuchus hingleyae gen. et sp. nov. (LYMPH 2021/45). A, right anterior dentary fragment in dorsal view; B, medial view of the same; C, posterior left dentary fragment in lateral view; D medial view of the same; E, posterior left mandibular fragment in lateral view. Abbreviations: an, angular; D1–D5, second through fifth dentary alveoli and/or teeth; den, dentary; dg, dentary groove, g cor, groove for articulation of anterior process of coronoid; mf, Meckelian fossa; t, posterior dentary teeth.

FIGURE 7. Cervical and dorsal vertebrae of Turnersuchus hingleyae gen. et sp. nov. (LYMPH 2021/45). A, digital model of vertebral series of the last five cervical vertebrae with cervical ribs in right lateral view; B, line interpretation of same (without the ribs); C, line interpretation of the first cervical vertebra of the series in anterior view; D, line interpretation of same in right lateral view; E, line interpretation of same in ventral view; F, digital model of vertebral series of the first five dorsal vertebrae with ribs in right lateral view; G, line interpretation of same (without the ribs); H, line interpretation of the second dorsal vertebra of the series in anterior view; I, line interpretation of same in right lateral view; J, line interpretation of same in ventral view. Abbreviations: aas, anterior articular surface; cr, cervical rib; dr1, first dorsal rib; dv1, first dorsal vertebra; dv2, second dorsal vertebra; dv3, third dorsal vertebra; dia, diapophysis; lcr, last cervical rib; lcv, last cervical vertebra; nsp, neural spine; pap, parapophysis; poz, postzygapophysis; prz, prezygapophysis; vk, ventral keel.

FIGURE 8. Block 2 containing four dorsal ver- tebrae, the right ulna, and dorsal ribs and gastra- lia of Turnersuchus hingleyae gen. et sp. nov. (LYMPH 2021/45).

FIGURE 9. Caudal vertebrae of Turnersuchus hingleyae gen. et sp. nov. (LYMPH 2021/45). A, block 5 containing caudal vertebrae from a relatively posterior position in series; B, block 4 containing one complete and one partial caudal vertebra from a relatively anterior position in the series; C, pair of likely caudal centra; D, second pair of likely caudal centra.

FIGURE 10. Appendicular bones of Turnersuchus hingleyae gen. et sp. nov. (LYMPH 2021/45). A, digital model of the right scapula and coracoid in lateral view; B, line interpretation of same; C, digital model of the proximal right humerus in medial view; D, right ulna in medial view; E, digital model of dorsal (caudal?) osteoderm in dorsal view. Abbreviations: co, coracoid; cf, coracoid foramen; dc, deltoid crest; dpc, deltopectoral crest; gl, glenoid fossa; hs, humeral shaft; ol, olecranon process; pt, pits; sc, scapula; scb, scapular blade; us, ulnar shaft.