634 SCIENTIFIC RECORD FOR 1884. 



Keiv American Dinosaurs.— Fi of t^ssor Marsh has contiEued his iuvesti- 

 gations of Hie American Jurassic Dinosaurs, notices of which have been 

 published in previous numbers of these reports of progress, by the de- 

 scription of anew family of "Sauropoda." A considerable portion of 

 the skeleton of one of the species of the group was exhumed, and it 

 was ascertained that the new family called Diplotlocidce was related to 

 the Atlautosanridse and Morosauridae, and distinguished by the follow- 

 ing characters : 



Sauropodous Dinosaurs with the ischia having straight shafts directed 

 downward and backward, the ends meeting at median line; a large 

 pituitary fossa, and anterior caudal vertebrae deeply excavated below. 



Two si3ecies of the family have been made known, which have been 

 named Diploclocus Jongus and Diplodocus laciistris. The D. longus was 

 intermediate in size between the previously known Sauroi)ods, and is 

 supposed to have been about forty or fifty feet long when alive. The 

 teeth show, according to Professor Marsh, that "it was herbivorous, and 

 the food was probably succulent vegetation. The position of the exter- 

 nal nares indicates an aquatic life." The remains of the I>. Jongus were 

 found in Upper Jurassic beds near Canon City, Colo., and those of the 

 J), lacustris near Morrison, Colo. All of the American Sauropod Dino- 

 saurians, hitherto obtained, have been found in Upper Jurassic rocks, 

 and no Cretaceous forms of this group are known. The group is sup- 

 posed by Professor Marsh to have the nearest affinities, of all the Dino- 

 saurs, with the Crocodilians. [Am. Journ. Sci. (3), xxvii, pp. 162-168, 

 pi. 3, 4.) 



United metatarsal Bones in a Reptile. — Last year a Dinosaurian reptile 

 was described as Ceratosaurus nasicornis, whose most interesting fea- 

 ture is to be seen in the metatarsal bones. "There are only three me- 

 tatarsal elements in each foot, the first and fifth having apparently dis- 

 ai)peared entirely," while the remaining three had become "completely 

 aukylosed," and very much shorter and more robust than in the other 

 members of the group to Avhich it belongs. In fact, the union of the 

 metatarsal elements in the Dinosaur is as perfect as is that in ordinary 

 birds. The position of the foramen, so characteristic of recent birds, 

 is also the same in the Dinosaur. Professor Marsh summarizes that all 

 known adult birds, " with possibly the single exception of Arclueopteryx^ 

 have the tarsal bones firmly united, while all the Dinosauria, except 

 Ceratosaurus, have these bones separate. The exception in each case 

 brings the two classes near together at this point, and their close affinity 

 has now been clearly demonstrated." {Am. Jour. 8c. (3), xxviii, pi>. 

 161, 162.) 



The Pteranodons or toofJiless Pterodaetyles. — In 1872 Professor Marsh 

 briefly noticed some remains of reptiles exhumed from middle Cretaceous 



