A Robust Bone

Even with having to pack up the paleo lab’s contents in the old building, and move, upack, and reorganize them in the brand new lab in the new BLM building, some great progress has been made on Basilemys.

The team decided to completely excavate each element inside his shell rather than leave them in place and be satisfied showing off the bones they had already partially exposed.  This allows them to explore the entire inside of the shell to find more bones, if there are any, and assure themselves they haven’t missed something good.  Removing all bones may actually provide the opportunity to learn more about Basilemys.

Here is a picture of our favorite tortoise taken a while back, before he was flipped over.  The blue outline indicates shell, the red may be a vertebra, the yellow is part of the coracoid (bone forming a joint between the shoulder blade and sternum), and the green is the elbow end of the humerus.

 

 

 

Flipping the tortoise allowed the team to positively identify some of these bones and, in some cases, see the entire bone structure. The humerus and small section of shell to the right of it were prepared, revealing what is shown in the photo on the right.  Outlined in blue is the shell, green shows the two ends of the humerus, purple is the shoulder blade, and yellow and orange are parts of the coracoid.

Removing the section of shell covering the rest of the humerus allowed the entire bone (outlined in green in the photo below) to be exposed.

 

 

 

 

 

 

By the end of the day the entire humerus was able to be lifted out. Left behind, for now (photo on right), are the shoulder blade (purple) and exposed coracoid (yellow).  The area in the circle shows where the first end of the humerus was exposed when Jim originally started working on it.

 

 

And here is the humerus in all its glory!

 

 

 

The first four photos, starting from the left, show all sides of the humerus with the shoulder socket on top and the elbow joint on bottom.  In the rightmost photo, on top is a view of the shoulder joint head on; on the bottom is a head-on view of the elbow joint.

You can see how robust the humerus was.  Its size and thickness mean it was definitely designed to bear weight.  Paleo lab manager Tylor commented, “If you handed just this bone to me, I would think it was not a turtle bone.”

Jim has started to prepare out the shoulder blade and the coracoid.  Right behind the coracoid is what is thought to be a vertebra.  Stay tuned to see what surprises Jim may uncover in the coming weeks.