THE 



GEOLOGICAL MAGAZINE. 



NEW SERIES. DECADE IV. VOL. I. 



No. VIII.— AUGUST, 1894. 



o:eixg-xi<tj^Xj jlisticXjES. 



I. — Footprints of Vertebrates in the Coal-measures of Kansas. 



By Prof. 0. C. Marsh, M.A., Ph.D., LL.D., F.G.S. ; 

 of Yale College, New Haven, U.S. 



(PLATE XI.) 



THE Museum of Yale University contains a small collection of 

 footprints of much interest, which were found in ] 873, in the 

 Middle Coal-measures, near Osage, in South-eastern Kansas. A 

 careful re-examination of these footprints has been i-ecently made by 

 the writer, and the main results are given in the present paper. 



The impressions are well preserved in a calcareous shale, which 

 separates readily into thin slabs, each representing a surface of the 

 beach at the time the footprints were made upon it. A few shells 

 in the shale are sufficient to prove that the formation is marine. 

 Trails of annelids, and perhaps of other invertebrates, are seen on 

 some of the surfaces. The footprints of vertebrate animals, however, 

 are of paramount importance, and the large number and variety of 

 these here recorded on a single surface, if they could be rightly 

 interpreted, would form an interesting chapter of land vertebrate 

 life in the Carboniferous period, about which so little is at present 

 known. 



On Plate XL, accompanying the present article, five distinct 

 series of footprints are shown, each one-twelfth natural size. All 

 were found on essentially the same surface, and at one locality. 

 The five different animals they represent were thus contemporaries, 

 and indicate a wealth of air-breathing vertebrate life at this period, 

 hitherto unsuspected. 



With these impressions were still otliers, made either by animals 

 nearly allied, or by the same animals under different circumstances. 

 These need not be further noticed in this connection, but they serve 

 to emphasize the diversity of life at this point. The typical series 

 are briefly described below. 



Nanopus caudatus. PI. XI. Fig. 1. 



The first series represented on Plate XL Fig. 1 indicates the 

 smallest animal that here left a distinct series of footsteps, and the 

 only one in which an imprint made by the tail was preserved. 

 This small quadruped had evidently but three functional toes on the 



DECADE ly. TOL. I. NO. Till. 22 



