Sinclair— A Large Parasuchian. 457 



Art. XXXI. — A Large Parasuchian from the Triassic 

 of Pennsylvania; by W. J. Sinclair. 



Some years ago, the Geological Department of Prince- 

 ton University acquired by purchase from Doctor R. S. 

 Stahle some Parasuchian bones collected by him and 

 Mr. R. C. Bair near York, Pennsylvania, from the red 

 Triassic shales of the Newark group. Upon comparison, 

 the bones prove to be referable to the form described by 

 von Huene from the Triassic shale twenty feet below the 

 Palisade diabase sill near Fort Lee opposite New York 

 City, now in the American Museum of Natural History, 

 and named by him Rutiodon manhattanensis. The Penn- 

 sylvania specimen, No. 11544 Princeton University 

 Geological Museum, comprises both ilia, the left 

 femur, the last presacral and first sacral vertebrae, an 

 incomplete anterior caudal, the centrum of an anterior 

 thoracic vertebra, a thoracic rib and several rib 

 fragments, various scutes, a number of teeth and some 

 indeterminate material. The general characters of the 

 parts are fairly apparent from the accompanying draw- 

 ings and only such as are not well shown need be 

 described in detail. 



The ilium and femur agree so closely in size and struc- 

 ture in the Fort Lee and York specimens that the specific 

 identity of these two is beyond question. As pointed out 

 by von Huene, the femur is of record size for a Para- 

 suchian (43-44 cm. long in the Fort Lee specimen, 41% in 

 that from Pennsylvania), and, except for its greater 

 curvature, resembles that of the Triassic Theropoda. 

 The ilium is in contact with two sacral vertebrae, as shown 

 by the articular surfaces. Of these vertebrae, only one is 

 preserved, the anterior, seen from in front in fig. 3. The 

 sacral ribs are completely fused with arch and centrum, 

 although traces of suture remain. The base of the rib is 

 expanded anteriorly and articulates with a facet on the 

 hinder border of the centrum of the last presacral ver- 

 tebra, (s, figs. 2 and 3). At the distal end of the sacral 

 rib, both anteriorly and posteriorly, there are facets for 

 contact with the ribs of the last presacral and second 

 sacral respectively. In the last presacral (fig. 2), unlike 

 the condition in the smaller Rutiodon carolinensis as 

 described by McGregor, the rib is firmly fused with arch 



Am. Jour. Sci.— Fourth Series, Vol. XLV, No. 270.— June, 1918. 

 32 



