Fossil Friday!

Raymond M. Alf Museum of Paleontology, Claremont, California. 

This week on Fossil Friday, I bring you, by special request, a trace fossil. What is a trace fossil? Well, it's a fossil that doesn't show the organism's structure itself, but rather its activity. Trace fossils include feeding marks, bioerosion, and even burrows. The ones depicted here are actually footprints, but whose?

If you follow fossil news, you would have seen these recently, as they were a cool new discovery. I contacted the researchers involved and they kindly offered to let me feature their find here too! If you already know it from reading the media stories, don't give it away! Only genuine guesses, please. 

So what left these marks? A prehistoric rabbit? A tiny-toed shrew? A bird pecking for dinner? A hopping grasshopper?

You tell me. The first person to identify it wins bragging rights for the week.