Sellards — New Gavialfrom Late Tertiary of Florida. 135 



Art. XI.— A New Gavial from the Late Tertiary of 

 Florida • by E. H. Sellards. 



The crocodilian remains described in this paper, including 

 the anterior part of a cranium and part of a lower jaw, were 

 obtained by Mr. Anton Schneider, general manager of the 

 Amalgamated Phosphate Company, and were by him presented 

 to the Florida State Geological Survey. The specimens are 

 from the Company's mine at Brewster, Polk County, Florida, 

 and were obtained in mining phosphate rock. The deposits in 

 which the fossils are found, the Bone Valley formation, are 

 either of upper Miocene or of lower Pliocene age. The asso- 

 ciated fossils, although not fully studied, are known to include 

 rhinoceroses, probably Teleoceras fossiger and one or two other 

 species, one or two species of Hipparion, and one or two 

 species of mastodons, including apparently the form described 

 as Mastodon floridanus by Leidy. Fish and cetacean remains 

 as well as crocodilian teeth are present, the deposits being of 

 shallow water, marine or estuarine origin. 



Of the Eusuchia, the sub-order to which is referred some of the 

 late Mesozoic and all of the Cenozoic and recent Crocodilia, four 

 families are recognized as follows : Alligatoridae, Crocodilidse, 

 Tomistornidae and Gavialidae.* Of these families, the Alligator- 

 idae and the Crocodilidae include, with some exceptions among 

 the crocodiles, short snouted species, while the Tomistornidae and 

 Gavialidae include long snouted forms. Further distinctions 

 are found in the lower jaw, the symphysis of which, in the 

 Alligatoridae and Crocodilidae, is short, never extending accord- 

 ing to Gadow beyond the eighth tooth, while in the Tomis- 

 tornidae and Gavialidae the symphysis is long never stopping 

 short of the fifteenth tooth. 



That the species described in this paper is to be placed with 

 the gavials rather than with the crocodiles is indicated not only 

 by the long snout and extended symphysis of the lower jaw, 

 but also by the fact that the first mandibular tooth bites on the 

 outside and not on the inside of the upper jaw. 



Between the Tomistornidae and the Gavialidae distinctive 

 characters are found in the relative extent of the nasals. In 

 the Tomistornidae the nasals are long and narrow and articulate 

 with the premaxillaries, while in the Gavialidae these bones 

 are remotely separated from the premaxillaries, from which 

 they are shut off by the maxillaries. Although of the skull 

 only the rostrum is preserved in the Florida material, the 

 position of the nasals, which extend to and are wedged in 



*Zittel, K. A., Textbook of Palaeontology, Eastman's Translation, vol. ii, 

 pp. 217-222, 1902. 



