26 NEW REPTILES AND STEGOCEPHALIANS PROM 



DESCRIPTION OF DESMATOSUCHUS SPURENSIS AND THE NEW 



SUBORDER DESMATOSUCHIA. 



The remains of this specimen were found near the east bank of the Blanco or 

 Catfish River, about a half mile east of the crossing of the old mail-road from Spur to 

 Crosbyton, in Crosby County, Texas. The site of the discovery is a patch of sand and 

 sandy clay occupying not more than a few hundred square feet, about a half mile north 

 of the road. This patch lies within a half mile of one of the areas of exposure of sands, 

 clays, and conglomerates which mark the occurrence of old river-washes at rare inter- 

 vals, among the barren clays of the Upper Triassic. The particular patch of sand and 

 clay in which the specimen occurred was evidently accumulated in some isolated hole 

 distinct from the nearest large area of river deposit. No other bones were found within 

 half a mile of the spot, and this important point, bearing upon the association of the 

 bones found in one specimen, was checked during three separate visits to the locality. 

 In working the specimen out of the ground a few scattered bones were found in the 

 sandy clay of the upper part of the deposit, but the greater part of the material was 

 found in single mass near the bottom, where the matrix was a light-colored clay with 

 included grains of sand, abundant traces of badly decayed vegetation, and lumps of 

 charcoal. This part of the clay was filled with gypsum, which had in some places 

 badly rotted the bones and in other places formed a protecting coat which preserved 

 the surface in perfect condition. Next to the bones there was, in may places, a thin 

 layer of pyrite, which rendered the cleaning very difficult, especially the rugose surface 

 of the skull. The pyrite frequently penetrated and filled the small cavities and 

 foramina, making it especially difficult to work out some of the finer details. Some 

 parts of the matrix were very hard and colored a deep black ; when this sort of material 

 was in contact with the bone the preparation was even more complicated. 



It seems evident that the remains of the animal were washed into a hole with a 

 considerable amount of vegetable material and then the hole was filled with a cleaner 

 sand. There can be no question that the major portion of the bones found together 

 at the bottom of the pit belong to one specimen, but there is also no question that 

 some bones of a second individual found their way into the hole, as there is an excessive 

 number of dorsal vertebrae and there is a second axis. Only a very few of the char- 

 acteristic dorsal plates of Desmatosuchus were found among the abundant remains of 

 Phytosaurs in the adjacent regions of the county, suggesting the comparative rarity of 

 the form and perhaps its restriction to a certain habitat. The peculiar condition under 

 which the specimen was found and the fact that no other bones were found nearer to 

 it than a half mile must again be emphasized by the author as justification for associating 

 the bones in a mount. 



A preliminary description of this form has been published in the Journal of 

 Geology 1 . 



The material collected consists of the skull lacking the lower jaw and the anterior 

 end of the nose, the vertebral column, which is apparently complete to the sacrum and 

 a few caudal vertebras, the dorsal armor of the body and a portion of the tail, an im- 

 perfect right scapula, and a portion of the right side of the pelvis. A fragment of one 

 of the long bones is the single bit of evidence of the skeleton of the limbs. One small, 

 irregular plate was found with the mass of vertebras and may be taken as evidence of 

 the presence of isolated plates upon the sides or abdomen. 



The greater part of the material was found in an irregular heap, with no continuity 

 except in the cervical region and a few of the dorsals. A few of the plates seem to 



1 Case, E. C., Preliminary Description of a New Suborder of Phytosaurian Reptiles, with a Description of a 

 New Species of Phytosaurus, Journal of Geology, vol. XXVIH, No. 6, p. 524, 1920. 



