April 2 2017

MAKING TRACKS ON EARTH

Rex Burress

 

The thing about gravity is that it pulls everything down to earth, pulling footsteps into soft dirt, sand, or mud and leaving a sign of anything passing that way. Like a shadow, you can't escape it.

Tracks are a simple deduction, but often with our eyes looking straight ahead we overlook signs on the soil or things in the sky. Unless you're a habitual rockhound you may miss that coin in the dust or the rattlesnake at the side of the path! Fossils are part of the ground scene, too, and those mineralized remnants of the past have been eagerly sought in order to shed some light on what happened long ago. Fossils cling to the earth like a child to its mother.

Thus a story about fossil tracks in Death Valley has been in the news. Sometime in March ancient fossil footprints were stolen in a remote, restricted, canyon called “Barnyard” in the Valley, damaging a unique display of tracks made by saber-toothed cats, mastodons, camels, tapirs, and birds. The sign of animal passage was made in mud at a lake's edge about five million-years-ago [mya] and became fossilized and tilted vertically by earth movement, verifying the existence of those extinct animals. Part of the role of National Parks is preservation, and removing those wall-slabs of fossil tracks is like tearing the pages out of a history book and denying any further study for future explorers.

The fossil track episode is similar to the peril hanging over Indian petroglyphs in many of the Southwestern rock formations. Vandals just can't keep their devilish tools off of sacred artifacts, robbing the region of history and beauty. The ancient Americans made tracks of paint and peck on stone as surely as animals made tracks in the mud.

Even more colossal are the tracks made by dinosaurs! There are several places in the world where prints have been preserved, especially tracks of bird-like dinosaurs that left “gigantic bird tracks,” largely unexplained until the discovery of dinosaur bones. Even so, birds are considered descendents of Tyrannosaurus Rex-type of dinosaurs. “Avian dinosaurs!”

Dinosaur tracks are found most notably in North America in the Connecticut River Valley, especially near the Massachusetts' Holyoke Wilderness Reservation, an eight-acre area established in 1935 after one-foot-long, 200 mya tracks were found in 1802, the first in North America. Since then, the Theropod eubrontes tracks have been discovered elsewhere, and dinosaur remnants found in 37 states, such as at Dinosaur Ridge in Morrison, Colorado, a splinter of Dinosaur National Monument in Utah. Imagine the awe and disbelief of first finding the bones and tracks of those monstrous animals!

One great aspect of snowy conditions, aside from the discomfort and cold connected, is tracking animals in the snow when the fresh covering is like a page in a book, easily read by those acquainted with the track makers. There is no avoiding making a track in snow or soil for fox and rabbit! Anything that touches the ground leaves its snow story, an indication of the presence of creatures not easy to see in thicket habitats.

Death Valley sand dunes might seem barren and lifeless at first glance, but early in the morning before sand-blowing winds pick up speed, you can find a myriad of animal tracks left on a surface as smooth as mud or snow. Rodents such as the Kangaroo Rat are the most abundant track makers on the dunes, but various insects--beetles and sand wasp--show their activities. Even previous breezes leave lovely furrow marks on the sandy slopes. Watch!

“Everything that moves on the earth leaves a story. A glacial valley is as much of a track as the footprint.” --Tom Brown Jr. “The Tracker”

“Never forget the trail, look ever for the track in the snow or sand; it is the priceless unimpeachable record of the creature's life and thought, in the oldest writing known on earth.”

 

--Earnest Thompson Seton