Apatosuchus orbitoangulatus (F. Huene, 1932 b)

Sues, Hans-Dieter & Schoch, Rainer R., 2025, Synopsis of the Triassic reptiles from Germany, Fossil Record 28 (2), pp. 411-483 : 411-483

Apatosuchus orbitoangulatus (F. Huene, 1932 b)

Holotype.

SMNS 12353 b, partial, disarticulated but associated remains of a skull (Fig. 19 A ), including parts of both maxillae, nasals, frontals (mainly as impression in matrix), right jugal, right parietal, ventral process of right postorbital, nearly complete left squamosal, right quadrate, right pterygoid, part of possible vomer, incomplete basioccipital and parabasisphenoid, exoccipitals / opisthotics, supraoccipital, incomplete dentaries and splenials, nearly complete left angular, partial left surangular, right prearticular, and two incomplete ceratobranchials.

Type locality.

“ Weisser Steinbruch ” south of Pfaffenhofen, Heilbronn district, Baden-Württemberg.

Type horizon.

Middle Stubensandstein (S 2), Löwenstein Formation, Middle Keuper Subgroup. Age: Late Triassic (Norian: Lacian-Alaunian).

Diagnosis.

Distinguished by the following combination of features: dorsolateral ridge of squamosal not overhanging temporal region; dorsal surface of squamosal bounding supratemporal fenestra flat; ventral process of squamosal with faint lateral ridge; maxilla without distinct antorbital fossa and medial bony lamina bordering the antorbital fenestra; ventral margin of antorbital fenestra forming thickened rim; and lateral surface of dentary bearing prominent anteroposteriorly extending ridge (Sues and Schoch 2013).

Comments.

F. Huene (1932 b) originally described SMNS 12353 b and designated it as the holotype of a new taxon of ‘ podokesaurid’ theropod, cf. Halticosaurus orbitoangulatus . Rauhut and Hungerbühler (2000) reexamined the specimen and found no evidence in support of theropod affinities. They noted that it might represent a ‘ sphenosuchian crocodile’ (basal crocodylomorph). Subsequently, detailed preparation of SMNS 12353 b made it possible to examine the structure of the skull in detail and to confirm that cf. Halticosaurus orbitoangulatus is a pseudosuchian ( Sues and Schoch 2013 a). Sues and Schoch (2013) recovered this taxon among Loricata in their phylogenetic analysis, but Spiekman (pers. comm.) is currently reassessing its relationships.

References.

F. Huene (1932 b), Rauhut and Hungerbühler (2000), Sues and Schoch (2013 a).

Figures

Figure 19. Reptiles from the Middle Keuper Subgroup. A. Pseudosuchian Apatosuchus orbitoangulatus, holotype (SMNS 12353 b), disarticulated cranial bones. Scale bar: 1 cm. B. Plateosaurid sauropodomorph Plateosaurus trossingensis, holotype (SMNS 13200), skull in lateral view. Length of skull 33 cm. C. Coelophysid theropod Procompsognathus triassicus, holotype (SMNS 12591), partial postcranial skeleton in ventral view. Scale bar: 5 cm.