Oakland’s sidewalks contain their makers’ marks and other things besides. In that respect, they remind me of geological strata, a subject close to my heart. Throughout time — well, throughout the billion years or so since they first evolved — animals of all kinds have left their tracks on the ground, from insects to dinosaurs (shown here from Dinosaur Ridge, near Denver).
Fossil tracks are classified as ichnofossils — preserved remains not of organisms’ bones or shells, but their actual behavior. Here are some human examples from our sidewalks.
We understand what humans were doing when they left these signs, as surely as we know why they left dated stamps on the pavement. They were saying, in one way or another, “hello it’s me.” The other animals, like Pig-Pig above or the nameless dog below, we can guess, were forced into the act and were saying “let me go!”
When these hooftracks were made, the horse and its owner were probably both displeased. Oh, and the sidewalk maker too.
We don’t know what business this animal, a cat I think, was intent upon. But I can guess it was fed up with concrete by the time it finished licking its paws clean.
And as for the modern dinosaurs — pigeons — that left these three sets of tracks on Piedmont Avenue, they were probably doing the usual.
Tony Martin, a Georgia-based professor of paleontology, is fixated on trackways both ancient and modern. Check him out at georgialifetraces.com.
Oakland Underfoot 
Leave a Reply