One of the obstacles we face at Carmel Church is weathering. In Virginia’s wet and variable climate weathering rates are very high. Moreover, at Carmel Church the sediment chemistry is such that the sediment becomes very acidic when exposed to air and rain. The end result is that bones left on or near the surface rapidly develop a very hard crust that then eats into the bone. If the bone isn’t too thin and delicate and is collected quickly it’s sometimes possible to remove the crust, but if the bone has been exposed too long we usually can’t save it. That’s why we try to only expose bone as we remove it, and we don’t spent a lot of time on material that has already weathered.
Even so, we do collect the weathered bone, because occasionally we are able to recover fairly good material. That’s why we saved the lump shown above, which Tim collected from the weathered zone during our last excavation. In the field I suspected that this was a odontocete (toothed whale) atlas vertebra, the first bone in the neck. But I wasn’t sure how much was actually preserved, or what condition it would be in. What a difference six hours in the lab with a MicroJack makes:
As I had thought in the field, this is a fairly small odontocete atlas vertebra. In fact, it’s a type of atlas we see fairly frequently at Carmel Church; compare it to the two examples below (the scales are slightly different):
We now have at least five of these vertebrae in our collection, easily making it the most common odontocete atlas at Carmel Church (we have atlases from at least three other species). While I haven’t done the detailed comparisons yet, in size and shape this seems to be close to Xiphiacetus. This makes sense, as Xiphiacetus is the most common odontocete at the quarry, with parts of at least four skulls collected so far.