February 17, 2021

I’ve started planning for this summer’s field work out west. Feels very good to say/write that after not going out in 2020 due to the Covid pandemic. Hope to be fully vaccinated and that travel will be better by July. I’ll not be in crowds or on any planes, quite the opposite out west, but don’t want to carry anything or spread anything if folks are not yet protected from this drag of a disease. Enough of that; I’m planning our next trip and have a few friends talking about joining me and that’s a lot more pleasant to ponder.

Been working on a fossilized turtle shell I excavated several years ago from the Hell Creek Formation in Montana. I needed a break from the hard preparation I’d been stuck on from hadrosaur hip bones that are just fused solid with “ironstone.” Been good & fun to work on and discover something new. Turns out this turtle has mostly intact top shell (carapace) & bottom shell (plastron). My notes from when it was excavated only referenced seeing what I thought was the top shell – no idea if more was there or not. When removing fossils from the ground we normally dig a perimeter around the item then dig deeper, under it and build a plaster & burlap strip field jacket around the fossil, tucking it in “under” the bottom lip of matrix we’ve dug out. This hardens so we can “flip” it over and do same (field jacket) the bottom – usually without seeing any of the bottom of the piece you’re removing. So back at the prep workshop we really do have a chance at a second discovery as we remove rock and dirt away from the fossil to expose for the first time what we’ve actually discovered. Timothy Turtle here was basically complete AND greatly “smushed” over to one side. And yes, smushed, is a highly professional phrase for, well, smushed! The original shape is there for the carapace and the plastron but the shell that joins the top & bottom was forced laterally through the effects of time and weight on it from the big process of becoming fossilized.

Still pretty cool, I think. Approximately 66 million year old example of what a turtle looked like then – remarkably similar to some modern day turtles. Turtle and crocodiles have changed very little over these 66 million years. Someone smarter than me needs to explain how that still fits in with our basic understandings of evolution and how species adapt over time to protect their own survival. It may be that both these lines of animals had the basic traits that have been tuff and just kept on sustaining the species?

Here’s a few photos of “Timothy” showing how it looks just as the field jacket was cut back through to today’s status of almost finished with clean up. Enjoy

Bottom, plastron, worked on first.

Starting to look different as the hard, rock matrix is teased away from the surface of the fossil shell.

Now turned over to work the top, carapace, side of ol’ Tim. It’s now stabilized with glue and all of the plaster field jacket has been removed.

Carapace side up

Plastron up this photo. Best view of how misshapened it is.