last summer’s footprints are walkin’
walkin’ dove walkin’ dove walkin’ dove
through last summer’s sand
a dove walkin’ dove walkin’ dove
and where the footprints end
where the footprints end
what happened then?
— “Footprints“, Bill Callahan
I stepped into wet paint at the Hartman gardens, Lorin said “Dude you just stepped in the man’s paint.” You only get one shot (give or take) to get your body into the fossil record. There’s ample opportunity to leave your mark in other ways however.
Photo: Simon Sharville
As we traipse and course across the planet we frict against various materials. Most are outside the goldilocks zone, either too resilient or too ephemeral to mark our passing. In the urban environment wet paint and wet cement serve as tremendous media for tracking a few short hours in the life of a city.
Photo: Mr. Bullitt
Naturally occuring regolith can perform much the same function although the Earth’s surface is a dynamic place and these traces generally have a short lifespan. As with body fossils however, with untold billions of organisms dragging their selves hither and yon across the greater part of the planet it’s hardly a surprise that some of these tracks find their way into the rock record.
Ichnology is the study of second-hand structures that record the passing of a living organism. This encompasses borings, burrows, trails and crap. For all the appeal of coprolites, the most familiar vertebrate ichnofossils are surely trackways, footprints left in a soft substrate preserved by some accident of sedimentary history.
Fossil footprints have been in the news lately with not one but three important fossil footprint discoveries announced in recent weeks. To treat each with appropriate nuance would guarantee fatal miring, so with only cursorial commentary here they are:
Tyrannosaurus rex footprint? Snap! Here’s the National Geographic story. Actually, eff the footprint, one wants to get down on hands and knees and look for mammal teeth right? (I’m so over dinosaurs btw).
Unfortunately, I missed the SVP talk concerning Australian theropod tracks, but like we said: “eh, theropods. Who cares?” They probably had parkas. Brian does a better job with it.
Okay, now this is really interesting: pictured at top are 315 million year old tracks probably made by some of the earliest amniotes. And, apparently they’re greedy to get their paws on some sweet Canadian dollars.