A P P E N D I X 



Art. XLYIII. — Notes on Triassic Dinosauria ; by O. C. 

 Marsh. (With Plates XV, XVI, and XVII.) 



The presence of Dinosaurs in the Trias is indicated by 

 many footprints, and various bones, nearly all of which are 

 fragmentary. The footprints were long supposed to be those 

 of birds, while the osseous remains were most of them not 

 sufficiently characteristic to admit of determination. Three 

 or four specimens in this country, however, and as many more 

 in Europe, each with characteristic parts of the skeleton, have 

 been known for some time. These prove the Dinosaurian 

 nature of the animals beyond question, but throw little light 

 upon their exact affinities. Recently, the writer has obtained 

 from the Connecticut River sandstone the greater part of three 

 skeletons of small Dinosaurs, all of much interest. Some 

 portions of these have already been described,* and, in the 

 present paper, additional remains are figured, and with them a 

 few nearly allied fossils from European localities. The Triassic 

 Dinosauria as a whole will be discussed by the writer in a 

 later communication. 



Anchisaurus cohims. 



The type specimen of this species, one of the most perfect 

 Dinosaurs ever discovered, has now been worked out of the 

 hard matrix in which it was imbedded, and the skull and limbs 

 are represented in the accompanying plates. 



The skull was somewhat crushed and distorted, but its main 

 features are preserved, and its more important characters can 

 be determined with certainty. In Plate XV, figure 1, a side 

 view is given, one-half natural size. One prominent feature 

 shown in this view is the bird-like character of the skull. 

 The nasal aperture (a) is small, and well forward. There is a 

 large antorbital opening (b), and a very large orbit (o). This is 

 elongated oval in outline. It is bounded in front by the pre- 

 frontal, above by the same bone, and a small extent of the frontal, 

 and further back by the postfrontal. The postorbital com- 

 pletes the orbit behind, and the jugal, below. The supra- 

 temporal fossa {d) is large, and somewhat triangular in outline. 

 The infratemporal fossa is quite large, and is bounded below 

 by a slender quadrate jugal. The quadrate (q) is much inclined 

 forward. The teeth are remarkable for the great number in 



""This Journal, vol. xxxvii, p. 331, April, 1889; and vol. xlii, p. 267, Septem- 

 ber, 1891. 



Am. Jour. Sci. — Third Series, Vol. XL11I, No. 258. — June, 1S92. 

 36 



