Allodaposuchus precedens, NOPCSA, 1928

ALLODAPOSUCHUS PRECEDENS NOPCSA, 1928

( Figs 2–7 View Figure 2 View Figure 3 View Figure 4 View Figure 5 View Figure 6 )

Age View in CoL and distribution: Late Cretaceous (Early Maastrichtian), western Romania, Oarda de Jos (municipalities of Alba Iulia, SebeȘ and Vinţu de Jos; Alba district, Haţeg Basin, Sard Formation) and Vălioara (Hunedoara county, Densuş- Ciula Formation) ( Codrea & Dica, 2005; Bojar et al., 2011; Csiki-Sava et al., 2015) ( Fig. 1 View Figure 1 ).

Neotype: PSMUBB V 438 , a nearly complete skull from Oarda de Jos ( Romania) ( Figs 2 View Figure 2 , 3 View Figure 3 ).

Referred material: MAFI Ob 3131 ( Figs 4 View Figure 4 , 5 View Figure 5 ), a fragment of skull table from Vălioara, identified by Buscalioni et al. (2001) as the lectotype of Al. precedens . Nopcsa (1928) referred additional material to the same individual as the skull table, but this cannot be confirmed: MAFI Ob 3133, dorsolumbar vertebra ( Fig. 6A–F View Figure 6 ); MAFI Ob 5726, sacral vertebra ( Fig. 6G–J View Figure 6 ); MAFI Ob 3136, right ilium ( Fig. 7A–D); and MAFI Ob 3140, two partial femora ( Fig. 7E–L).

Diagnosis: Allodaposuchid characterized by the presence of an occlusion pit for reception of the fourth mandibular tooth and the following exclusive combination of characters: pointed teeth with smooth mesiodistal keels delimited by grooves (shared with Ag. subjuniperus , Al. hulki and the Velaux-La Bastide Neuve form), with developed ridges between these grooves (shared with the Velaux-La Bastide Neuve form); five premaxillary teeth (shared with L. mechinorum and the Velaux-La Bastide Neuve form) and 13 or 14 maxillary teeth (shared with L. mechinorum , Ag. subjuniperus and the Velaux-La Bastide Neuve form); slender postorbital bar (shared with Ar. gascabadiolorum and L. megadontos ); small, almond-shaped incisive foramen (shared with Ag. fontisensis ); large medial jugal foramen (shared with Ag. subjuniperus , Al. hulki and the Velaux-La Bastide Neuve form); anterior lacrimal processes between nasal and maxillae (shared with Ag. fontisensis and Ar. gascabadiolorum ); anterior frontal process not extending beyond the anterior border of prefrontals (shared with L. megadontos ); jugal–quadratojugal sutures placed lateral to the posterolateral corners of the infratemporal fenestrae (shared with Ag. subjuniperus , L. mechinorum and the Velaux-La bastide Neuve form).

Description: MAFI Ob 3131 is an incomplete skull table whose postorbital, squamosal and part of the quadrates have been reconstructed ( Figs 4 View Figure 4 , 5 View Figure 5 ). The specimen does not preserve most of the braincase, because it is broken at the upper margin of the foramen magnum. It thus lacks the occipital condyle, basioccipital plate, basisphenoid, palatines, pterygoids, ectopterygoids, quadradojugals and jugals. The supratemporal fenestrae are rounded but slightly oval posteriorly. Although the supratemporal fenestrae have not been completely preserved, they seem to be smaller than the orbits. The medial and posterior orbital margins have been preserved, and they are slightly upturned with respect to the dorsal surface of the skull.

The frontal is depressed along the midline and is strongly ornamented with large pits ( Fig. 4A, B View Figure 4 ). Anteriorly, the frontal bears a long, narrow process that ends in a small notch at its rostral tip. The margins of the frontal, which are clearly visible, form the anteromedial angle of the supratemporal fenestrae and the posteromedial edge of the orbits. In ventral view, the olfactory passage forms a longitudinal groove with a well-marked ridge along the sagittal axis, which is delimited laterally by two ridges or cristae cranii sensu Iordansky (1973; Fig. 4C, D View Figure 4 ).

The parietal is flat and profusely ornamented ( Fig. 4A, B View Figure 4 ). Its suture with the frontal is nearly linear, with a modest, posteriorly oriented midsagittal concavity. In dorsal view, the posterior margin of the parietal has a midline notch contacting the supraoccipital. In occipital view, the parietal forms the dorsal margins of the posttemporal fenestrae.

Only the right postorbital is preserved. It is narrow and elongate, approximately half of the length of squamosal, and forms more than half of the lateral margin of the supratemporal fenestra ( Fig. 4A, B View Figure 4 ). The dorsal base of the postorbital bar is preserved on the ventral surface of postorbital ( Fig. 5C, D View Figure 5 ).

The ventral base of the postorbital bar is also preserved, which is inset on the medial surface of a small fragment of jugal ( Fig. 5C, D View Figure 5 ). Considering both fragments, we infer a slender postorbital bar. No medial foramina are observed on the jugal fragment.

The right squamosal is almost complete, except posteriorly, whereas most of the left squamosal is reconstructed ( Fig. 4A, B View Figure 4 ). Its dorsal surface is flat and highly ornamented. The squamosal has a ventrally deflected posterior expansion, although the distal end cannot be observed. In lateral view, a well-marked groove for the muscles of the ear flap is preserved ( Fig. 5C, D View Figure 5 ). The lower margin of this groove projects anteriorly almost to the level of postorbital bar without reaching it. The squamosal forms the roof of the otic recess, contacting the exoccipital posteroventrally and the quadrate anteriorly to the otic aperture. In occipital view, the squamosal forms a lateroventrally directed suture with the exoccipital. The squamosal forms the dorsolateral margin of the posttemporal fenestra, which is depressed with respect to the occipital area ( Fig. 5A, B View Figure 5 ).

The right quadrate is complete, whereas the left one has been reconstructed posteriorly ( Fig. 4A–D View Figure 4 ). The quadrate forms the posterior wall of the infratemporal fenestra and the ventral margin of the temporal canal. The quadrate ramus is short relative to the posterior margin of the paroccipital process. The foramen aëreum is placed dorsomedially between the ventral margin of paroccipital process and the mandibular joint ( Figs 4A, B View Figure 4 , 5A, B View Figure 5 ). No crests are associated with the foramen aëreum. The articular condyle is slightly elevated in dorsal view, and the medial hemicondyle is dorsoventrally expanded. The squamosal does not contact the quadrate on the posterior region of the otic region; instead, there is an open cranioquadrate passage ( Fig. 5C, D View Figure 5 ). In ventral view, several ridges delimiting two depressions in the longitudinal axis of the quadrate are observed: a modest crest parallel to the medial margin of the quadrate, a longitudinally marked crest in the middle of the quadrate, and a soft transversal crest that reaches the lateral margin ( Fig. 4C, D View Figure 4 ).

Both laterosphenoids are almost complete, except the region of the left capitate process ( Figs 4C, D View Figure 4 , 5C, D View Figure 5 ). Anteriorly, these elements have markedly concave margins, and posteriorly, they preserve the concavities for the trigeminal foramina.

The supraoccipital is wide, low and subelliptical ( Fig. 5A, B View Figure 5 ). In occipital view, it forms most of the ventrolateral margins of the posttemporal fenestrae. The fenestrae are transversely elongate, and their ventral margins project posteriorly. The supraoccipital lacks a marked nuchal ridge. The supraoccipital participates in the posterior margin of the skull table, with a large exposure in dorsal view ( Fig. 4A, B View Figure 4 ).

The exoccipitals are almost completely preserved except for their ventromedial regions ( Figs 4A, B View Figure 4 , 5A, B View Figure 5 ). They are strongly depressed medially. Each exoccipital has a robust ventrolateral expansion and overlaps the dorsomedial surface of the quadrate laterally, forming a tubercle on the ventral margin of the paroccipital process in the posterior aperture region of the cranioquadrate passage. The paroccipital process slightly surpasses the level of the medial margin of the quadrate condyles. The exoccipitals meet at the midline and form the roof of the foramen magnum, but only the dorsal half of the foramen magnum is preserved. No foramina are preserved adjacent to the foramen magnum. Laterally, the exoccipital comprises the ventral surface of the otic aperture. In the medial area of the cranioquadrate passage, the exoccipital bears a ventral lamina that overlaps the medial side of the quadrate.

MAFI Ob 3133 is an almost complete procoelous dorsolumbar vertebra ( Fig. 6A–F View Figure 6 ). Its neural spine is broken at the base. The transverse processes are broken distally. The centrum is twice as long as its height and width. It is slightly wider than high anteriorly, whereas the posterior surface of the centrum is similar in height and width. The centrum bears a prominent posterior cotyle. Parapophysial facets are posteriorly located on the bases of the transverse processes. There is no ventral centrum keel.

MAFI Ob 5726 is a procoelous sacral vertebra, in which the right prezygapophysis, part of the caudal region of the centrum, the neural spine and the left postzygapophysis have been reconstructed ( Fig. 6G–J View Figure 6 ). The left prezygapophysis and the right sacral rib are also broken at their distal ends. The vertebral centrum is approximately twice as wide as the height anteriorly and subcircular, posteriorly bearing a convex cotyle which is not as pronounced as that of MAFI Ob 3133. This vertebra has robust transverse processes fused with the sacral ribs.

MAFI Ob 3136 is a right ilium ( Fig. 7A–D). The distal end of the iliac blade and the postacetabular process are broken. It has a thick supraacetabular crest and a reduced anterior process. The wide acetabulum opens ventrally and is preceded by a bilobate preacetabular process. The iliac blade has a convex outer profile with a marked tubercle towards its posterior tip. The upper edge of the iliac blade and the supraacetabular crest show numerous scars for muscle insertion.

MAFI Ob 3140 is a pair of incomplete femora. One is a right femur lacking its distal end ( Fig. 7E–H). The other is a left femur missing its proximal end, which has been reconstructed. The proximal end and part of the diaphysis of the left femur were attached to each other upside down; it is thus split in two parts in Fig. 7I–L and properly aligned. The femur ( Fig. 7E–H) is sigmoidal and has anterior and posterior proximal shallow tubercles. In anterior view, a ridge arises at the proximal end of the shaft, extends distomedially from the lateral margin and ends near the medial margin. There is a well-developed fourth trochanter. Distal condyles are separated by the intercondylar groove, and the lateral hemicondyle, which contains the fibular condyle, is larger ( Fig. 7I–L). A groove separating the fibular condyle from the rest of the lateral condyle can be discerned in lateral view.