Geological facts; or, the crust of the earth, what it is, and what are its uses

by W. G. Barrett

CASTS OF RAIN-PRINTS.

Again, let us hear the words of Professor Ansted. “It may appear at first sight that nothing can be more fleeting, or less likely to be handed down to future ages, among the fossils of a bed of sandstone, than the casts of the impressions of the footsteps of an animal, which by chance may have walked over that bed when it existed in the condition of loose sand forming a seashore. A little consideration, however, will show that it is in fact a very possible occurrence, as, if the wet sand should be immediately covered up with a thin coating of marl, and another layer of sand be superimposed, such an impression will be permanently preserved. In after ages, also, when the soft sands have become sandstones, and are elevated above their former level, the stones split asunder wherever a layer of different material occurs; and thus it happens that the casts of the footsteps may be preserved and exhibited, although all other traces of the former existence of the animal have been lost.”[^[67]]

FOOTPRINTS OF A TRYDACTYLE BIRD, AND IMPRESSION OF RAIN.
(Nat. size.)

If we go to the British Museum, on the north wall of room No. 1. we shall find slabs of sandstone containing footprints of animals, apparently bipeds and quadrupeds, of which we find the following notice in the catalogue of the Museum; and when this description is compared with the three drawings that follow, we make no doubt of carrying the conviction of the reader along with our own, as to the origin of these extraordinary ichnites,[^[68]] as such petrified prints are termed:—“The slabs of sandstone on the north wall of this room, with the supposed tracks of an animal called Cheirotherium, are that on the left from the quarries of Hildburghausen in Saxony, and that in the centre from those of Horton Hill, near Liverpool, (the latter presented by J. Tomkinson, Esq.) On the right hand are placed slabs from the same new red sandstone formation, with equally enigmatical imprests of various dimensions, called Ornithichnites,[^[69]] being very like footmarks of birds; they occur in the sandstone beds near Greenfield, Massachusetts, at a cataract in the Connecticut River known by the name of Turner’s Falls.”

FOOTPRINTS OF BIPEDS (BIRDS?) PROM TURNER’S FALLS.
(Size of slab, 8 ft. by 6.)

The lines in this drawing are merely to indicate the direction, the line of progress, of these bipeds, and the reader by following the lines will find the illustration all the more interesting.

But the most remarkable footprints preserved on slabs of sandstone are those of a quadruped, whose hinder feet were much larger than his fore feet. Some of our marsupial[^[70]] quadrupeds, such as the opossum and kangaroo, and many species of batrachian[^[71]] reptiles, are distinguished by the same peculiarity. Below is a copy of this slab, which is in the window recess of the same room of the British Museum.