ORDER VII 



CROCODILIA 



209 



primitive position on either side of the vomers. Palatals and pterygoids not meeting 

 in the middle line. Supratemporal vacuities very small ; lateral vacuities large, covi- 

 pletely enclosed. Parietals and frontals paired; postorbitals distinct. Teeth with 

 anterior and posterior carinae. Vertebrae amphiplatyan. Coracoid short and 

 rounded ; clavicles present. Pubis, ischium,, and ilium all entering the imperforate 

 acetabulum. 



The Parasuchia of the Trias are commonly regarded as ancestors of the 

 longu-ostrate Crocodilians, which they resemble in numerous features, such as 



c 



Fig. 300. 



Belodoa JMpffi, v. Meyer. Upper Keuper ; Stuttgart, Wlirteinberg. Skull from superior (A), palatal (23), and 

 lateral (C), aspects, 1/7. A, Orbit; ang, Angular; art. Articular; bo, Basioccipital ; ch, Internal Jiares ; d, 

 Dentary ; D, Antorbital vacuity ; D'. Mandibular vacuity ; exo, Exoccipital ; fr, Frontal ; ju, Jugal ; I, Lachry- 

 mal ; rax, Maxilla ; N, External narial openings ; 71a, Nasal ; pa, Pai-ietal ; pi. Palatine ; pmx, Premaxilla ; pior, 

 Postorbital ; prf, Prefrontal ; ^3*, Pterygoid ; ptf, Postfrontal ; qu, Quadrate ; <juj, Quadrato-.jugal ; S, Lateral 

 temporal vacuity ; S', Supratemporal vacuity ; sq. Squamosal ; vo, Vomer. 



their considerable size, armouring of the trunk region, elongated rostrum, 

 coarsely sculptured cranial plates, separation of the lateral temporal vacuities 

 from the orbits, socketed teeth, structure of the lower jaw (which is pierced 

 in its hinder half by a vacuity), and prevalence of double-headed ribs. But 

 in addition to these characters they possess others which render their associa- 

 tion with Dinosaurs or Ehynchocephalians equally justifiable. Among features 

 they share in common with Dinosaurs may be mentioned the divided, remotely 



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