THE PHYTOSAURIA OF THE TRIAS 



MAURICE G. MEHL 



University of Wisconsin 



Some time ago the writer gave a brief notice of a new genus of 

 phytosaurs of which Angistorhinus grandis Mehl was the type.' It 

 is the purpose of this paper primarily to give a fuller description of 

 this form and of another specimen mentioned in the above paper 

 which further study has shown to be a new species of the same 

 genus. 



Angistorhinus grandis Mehl 



The general characteristics of the specimen upon which this 

 form is based were set forth in the previous paper and deserve but 

 brief mention here. The skull is elongate with the rostrum pro- 

 duced into a long, slender, depressed snout and the nares elevated 

 on a prominence at its posterior end. It is among the largest of 

 the phytosaurian skulls, with a total length of about 977 mm. The 

 squamosals extend a considerable distance beyond the posterior 

 border of the quadrates and are produced downward into stout, 

 hooklike processes. The supratemporal vacuities are closed pos- 

 teriorly by a well-developed parieto-squamosal arcade that lies in 

 the plane of the roof of the cranium. A m.arked depression is seen 

 on the dorsal surface surrounded by the orbits and supratemporal 

 vacuities. The irregular pitting of the surface is confined almost 

 entirely to the lateral and posterior sides of the prominence upon 

 which the nares are situated, and the flat dorsal surface of the 

 cranium back of this, and in front of the supratemporal vacuities. 

 In a lateral view the skull resembles that of Mystriosuchus Fraas^ 

 more than any of the other phytosaurs. 



^Joiir. GeoL, XXI (1913), 186. 



' Die Schwahischer Trias-Saurier nach dem Material der Kgl. N aturalien-Sammltmg 

 in Stuttgart ziisammengestellt (1896), p. 16, PL V. 



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