Description of a Fossil Saurian of the New Red Sandstone Formation of 
Pennsylvania ; with-some account of that Formation. 
By Isaac Lea, 
Mem. Am. Phil. Soc., The Acad, of Nat. Sci., &c. 
The existence of “fossil footmarks” was received with great doubt by geologists, 
when first announced, and it required numerous observations before such geological 
evidence was generally accredited. 
It appears that Dr. Duncan first noted these interesting and peculiar relics of 
ancient life, in 1828, having observed the impressions made by tortoises in the “ New 
Red Sandstone ” of Dumfriesshire in Scotland. A few years after this, among other 
discoveries, was that of the tracks of the Cheirotherium (Lahyrinthodon of Owen) in 
Saxony, where it was found also in the “ New Red Sandstone.” 
In this country, Dr. Deane and Professor Hitchcock observed fossil footmarks in 
the “ New Red Sandstone ” of the Valley of the Connecticut River, the age of which 
has been recently doubted by Elie de Beaumont and Dr. Jackson, who think it 
belongs to a lower member of the series. I do not myself incline to that opinion, having 
no doubt of its being a member of that group of red sandstones which form the masses 
between the carboniferous strata and the Lias. In 1836 Professor Hitchcock published 
his account of bird tracks, (Ornithichnites,) in the American Journal of Science, and 
his statements were received with a good deal of doubt, until, by repeated observations 
and publications by himself and others, geologists generally became satisfied with 
the established fact, that while there had not been found a single bone in these rocks, 
yet the undoubted foot-prints of numerous species of birds and reptiles, gave the 
fullest and most satisfactory evidence that, at that geological epoch, immensely 
remote, the plastic shores of these waters received the impression of numerous air 
breathing animals. Prof. Forbes has recently observed that “the symmetry with 
which the prints succeeded each other on the surface of the sandstone, &c., furnished 
an agreement, geometrical, no doubt.” 
Two years subsequently various foot-marks were found in the New Red Sandstone 
near Liverpool, and, subsequently again, they were found in various parts of 
England, and on the continent, in the same formation, as w’ell as in more recent 
strata. 
In the Valley of the Connecticut, Professor Hitchcock informs us, that sixteen 
quarries are known to produce foot-marks, and Mr. Redfield has observed them at 
Pompton, in New Jersey ; and, more recently, they have been found near Princeton, 
New Jersey, by Mr. Jones, an industrious young naturalist of the College there. In 
(From Journ. Acad. Nat. Sci., Part 3, Vol. IT., N. S.—Tlrad May llth, 1852.) 
