APPENDIX. 



THE BRIER CREEK BONE-BED AND ITS FAUNA. 



By E. C. Case. 



In the summer of 1912 the author discovered this large bone-bed on the 

 ranch of Mr. Estell, about 12 miles south of Dundee, a little east of the road 

 between Dundee and Archer City, in Archer County, Tex. The next summer, 

 with the help of Mr. W. I. Robinson, a graduate student in the University 

 of Michigan, the bed was excavated as far as time permitted (plate 21). 



The bones occur in a light gray clay near the top of the Wichita forma- 

 tion. As has been previously shown by the author, the road running south 

 from Dundee, in Archer County, Texas, marks approximately the first out- 

 crop of the limestones which are regarded as the lower deposits of the Clear 

 Fork formation. The bones were practically all isolated, but one or two par- 

 tially complete skeletons being found, and almost all of the skull material con- 

 sisted of separate bones. It is evident that the pool or swamp in which the 

 bones were collected was more or less of a macerating tank in which the skele- 

 tons went to pieces and were disturbed by movements of the slimy mud and 

 by the action of animals which trampled the decomposing bodies as they fed 

 upon them or in their struggles to escape when mired. Toward one end of 

 the bed the lowermost bones rested upon a layer of coarse gravel, indicating 

 that a current may have swept the cadavers into the pool. As the bones are 

 in many cases badly fractured and show signs of decay, but are never water- 

 worn, it is probable that the bones themselves were not disturbed by currents 

 after the bodies were macerated. Unfortunately the layer which contains 

 the buUc of the bones was invaded, either before or after the solidification of 

 the mud, by waters rich in iron, which destroyed the surface of the bones and 

 at the same time cemented them into a hard mass from which they can not 

 be recovered. Both above and below this layer there was an abundance of 

 material in splendid condition, but if it had not been for the accident of the 

 iron-bearing water invading the deposit the bones recovered would have been 

 numbered by thousands instead of hundreds. 



One of the first specimens discovered was the nearly complete skeleton of 

 an Edaphosaurus cruciger Cope, consisting of the vertebral column to the base 

 of the tail, most of the limb bones, the pelvic and pectoral girdles, and an imper- 

 fect skull. This gave hopes that other associated skeletons would be found, a 

 hope that was, unfortunately, not realized. There have been identified: 



Dimetrodon incisivus Cope. Cricolus helerocUtus Cope. 



Dimelrodon sp., small form. Diplocaulus sp. 



Theropleura sp. Trimerorhachis (?) sp. 



Clepsydrops natalis Cope. Dorsal plate of a member of the Dissorhophids. 



Diadectes sp. Dermal scutes of an amphibian. 



Diadecles maximus Case. Numerous bones of amphibians and reptiles, many 



Bolosaurus striatus Cope. belonging to new forms, but some undoubtedly 



PoUosaurus sp. belonging to known forms described from incom- 



Archeria robinsoni genus et sp. nov. plete material. 



Eryops megacephalus Cope. 



157 



