560 POPULAR SCIENCE MONTHLY 



These deposits are in the form of a thick bed of coal which has been 

 opened up by modern industry which has cast aside as useless the blocks 

 on which are preserved the priceless relics of the creatures of this 

 bygone time. There have been great numbers of these blocks of coal 

 collected by geologists, but in all probability the greater part of the 

 animal remains preserved in the coal has gone to furnish heat for the 

 people of the region. 



The animals, which have been obtained from the old Diamond mine 

 near the village of Linton, Ohio, are imbedded in the coal which 

 formed from the vegetation growing on the shores of the lake in which 

 the coal accumulated. 2 This old lake was probably of but limited 

 extent and may not have measured more than six miles in its greatest 

 diameter. In this lake lived and died for ages the animals whose 

 remains represent the first recorded appearance of quadrupeds on the 

 earth. There are, to be sure, deposits in Illinois which are of con- 

 temporaneous age, but so far only five specimens of amphibia have been 

 discovered in these deposits, so they are hardly to be taken into account 

 when compared to the hundreds of specimens obtained by Dr. J. S. 

 Newberry from the Linton locality. The animals which disported 

 themselves in this old lake, at their death fell to the bottom and their 

 remains, what was left of them after their former companions had 

 feasted on their bodies, were covered with the mud and vegetation which 

 drifted in upon them. Thus they are preserved to us. 



The student of these remains finds them greatly different from the 

 amphibians of to-day. There were some forms which were large, but 

 the majority of them were small. Some may have reached a length 

 of ten feet while a great many did not exceed six inches and a few were 

 less than five in extent. There is one little form from Illinois, to be 

 described further on, which barely attained a length of two inches 

 in the adult state. Some of the Amphibia from the Linton mines 

 represent snake-like forms with the proportions of the modern whip 

 snake of the western plains, though not with its dimensions. Others 

 more nearly resembled the modern lizards and this resemblance was 

 carried to the extent of the possession of strong teeth and clawed digits. 

 There was no osseous carpus and tarsus, however, so that they are 

 distinct from the lizards structurally. Still other of these early quad- 

 rupeds must have resembled the modern crocodiles in appearance and a 

 few may have attained nearly the dimensions of these forms. There 

 were forms which were partially protected by hard dermal plates, at 

 least on some parts of the body. Some, like the fishes, had rounded 

 scales which covered the entire body, while a few appear to have been 

 entirely naked. All the forms appear to have possessed the ventral 

 armor of dermosseous rods or scutes which protected the abdomen much 

 as the abdomen of the Sphenodon of New Zealand is protected to-day. 



2 Newberry, J. S., 1S89, Monograph U. S. G. S., Vol. XVI., p. 211. 



