UNIVERSITY OF CALIFORNIA PUBLICATIONS 

 Bulletin of the Department of Geology 



Vol. 3, No. 21, pp. 419=421. ANDREW C. LAWSON. Editor 



A NEW MARINE REPTILE 



FROM THE 



TRIASSIC OF CALIFORNIA 



BY 



John C. Merriam. 



In the collections of marine Triassic reptiles at the University 

 of California there are a number of specimens representing' a 

 heretofore unknown form of swimming' reptile. In advance of 

 a more complete discussion of the structure and affinities of this 

 group, the following description of the type specimen is presented. 



Thalattosaurus alexandrae, new gen. & sp. 

 Figure l. 



Cranium elongated, with slender snout. External nares 

 separated and not far in front of the orbits. Dentigerons 

 portion of the premaxillaries elongated but shorter than the 

 maxillaries. Premaxillaries and maxillaries sculptured on the 

 external surface. 



Vomers with two rows of Mat, button-like teeth. Pterygoids 

 with four or more rows of curved, conical teeth. Palatines not 

 known to be dentigerous. Teeth of the premaxillaries and of 

 the anterior end of dentary slender conical. Posterior part of 

 dentary and probably of maxillaries with button-like, flat or 

 only slightly tuberculate teeth. 



Vertebrae amphicoelons, neural spines slender. Dorsal ribs 

 single-headed. Coracoid reniform, elongated antero- posteriorly. 

 Scapula narrow. Humerus short, much expanded distally. 

 Radius and ulna about half the length of the humerus; radius 

 with median constriction. Pelvic arch robust, inferior elements 

 not plate-like. 



