Flat Heads

Holotype fossil. Left, photograph, Right, interpretive illustration. A, dorsal view; B, left lateral view; C, rostral view; D, caudal view. Scale bar equals 1 cm. Abbreviations: adt, adductor tubercle; bo, basioccipital; boss, integumentary boss; bs, basisphenoid; cc, cranial cavity; chr, choanal recess; cp, cultriform process; dtf dorsotemporal fenestra; dtfo, dorsotemporal fossa; eam, external auditory meatus; ept, epipterygoid; fm, foramen magnum; fr, frontal; fso, supraorbital nerve foramen; fX-XI, foramen for cranial nerves X and XI; fV_2,3, maxillomandibular foramen; gV₁, ophthalmic groove; ls, laterosphenoid; mec, middle ear cavity; oc, occipital condyle; pap, paroccipital process; po, postorbital; pop, postorbital process; ppr, post-occipital protuberance; qu, quadrate; sq, squamosal; sup, supraoccipital; vf, vascular fossa; vg, vascular groove.

The holotype material of Aegisuchus is a little difficult to interpret the first time one looks at it with no direction or insight into the fossil. However, with even a fragmentary picture of the head of an alligator one should be able to notice the nearly symmetrical foramina on the top of the head. After noticing that it is fairly straightforward. The frontals can be seen extending rostrally from the foramina giving a solid interpretation of rostral and caudal areas of the fossil. Additionally, when viewed caudally the occipital condyle is easily seen; in the highly detailed 3D printed model of the fossil the condyle is unmistakeable whereas it may be lost a little in the photos above.  The foramen magnum is also easily seen and, thanks to the wonders of science (i.e. CT scanning and digital modelling), an endocast of the brain is also available. The printed model of the brain amazes people when we tell them what it is.