Footprints on the Sands of Time

Footprints on the Sands of Time By Fred Buss, Department of Geology, Brigham Young University. Anyone who has wandered along the seaside and played or dreamed on the beach, has surely sometimes written his name in the sands and then watched the incoming waves wash out the record forever. To us the shifting sands of the shore are symboli- cal of all that is unstable and fleeting, and it seems especially unlikely that on them could be preserved any permanent record of any event that may have transpired there. Yet the geologist knows full well that the record of past events in the earth's history is more permanently written on the muds and sands of the shore or delta flat than are human records on papyrus or sheepskin, and the interpretation of the shore line hieroglyphics is about as certain as those on the monuments of Egypt or Assyria. Four miles east of Heber City, Utah, at the mouth of Lake Creek Canyon, is a quarry of red sandstone, now practically abandoned because of the competition of the cement window sill and paving block. The soft, red rock of this quarry evidently represents the debris of a land mass brought hither by some an- cient stream or washed by the ocean waves from some sea cliff and then deposited in some sheltered cove of a long vanished Triassic or Jurassic sea. The sandstone of this quarry is crossed and recrossed with innumerable footprints of various small bipedal creatures which walked or rather waddled across the sand flat, evidently in search of the bodies of sea animals which might have been left exposed by the retreating tide. Sometimes one can observe where these little creatures paused in their walk to dig for some- thing buried a few inches beneath the surface in the soft sand. The accompanying illustration shows the tracks preserved on two slabs of rock which were collected in this locality. The larger slab is about three and one-half feet by one foot, entirely crossed by the tracks of a little animal which could have been but little larger than a half-grown chicken. The trail of the right foot is nearly two inches from the trail of the left, yet the distance between the steps is barely one and one-quarter inches. Evidently the creature's legs were very short and placed far apart and he must have had a very pro- nounced waddle as he progressed along the sandy flat. The

160 IMPROVEMENT ERA Animal tracks in red sandstone, found near Heber, Utah, by the Brigham Young University, Geological Department, October, 1921.

FOOTPRINTS ON THE SANDS OF TIME 161 straightness and regularity of his steps indicate a mind at peace with his surroundings and apparently solely intent on seeking what he might devour. Each foot seems to have possessed three toes, but one of them, the inner, was placed far from the other two and seems not to have borne much of the body's weight. The tiny impres- sion of this third toe can be seen inside of the main print. The larger track represents that of an animal much more upright in habit and perhaps one as large as a rabbit. Like the other, it evidently walked on two legs perhaps balancing him- self by means of a long tail, although it seems strange that we should not find the print of such an appendage as the animal walked along. The prints of these tracks are about four inches apart and it is about one and one-half inches between the right and the left impressions. This creature also seems to have had three toes although they were so closely crowded together that the print of each partly obliterates the others. No skeletons of these animals have aa yet been found, but their habits suggest that they were carnivorous forms. If this be true, their bones should some day be found in the deposit, for life must have been uncertain with them, in the presence of the numerous other forms. Then, too, it seems that their bones would be quickly buried even as their tracks have been. We cannot tell whether or not these animals were nocturnal in their habits for, as far as I know, theie is nothing preserved to tell whether the sun or the moon was shining on the sandy waste when these little creatures went hunting; but we feel quite sure that it sometimes rained, as many of the slabs of this rock are pitted exactly as if a shower had passed over during the interval between high and low tide, and these rain-formed pits were filled with sand when the advancing waves on the breast of a rising tide again swept over the area. These waves and cur- rents have also left certain evidence of their existence in the rip- ple and rill marks that are preserved along with the rain marks. It is impossible to state exactly what these animals were, Their bi-pedal gait and predacious habits, as well as their pres- ence in rocks of the Lower Mesozoic time, suggest relationship with the dinosaurs, but their feet are of uncertain form and it seems strange that such low hung animals as these evidently were could have walked over the sand without forming an imprint of their long tails, had they belonged to that reptilian race. At any rate we have here a field that is very promising for future study and one which will probably reveal many instructive lessons to the geologist who engages in painstaking and systematic col- lecting. Provo, Utah.