Friday, September 2, 2011

Summer Field Work 2011 - Part 3

Week 7
Surface bone. What could it be? (Photo by Andrea Thomer)

Phytosaur skull.
This was a somewhat slow week between office days and unproductive prospecting. Friday was spent back at Billings Gap where we had noticed several surface exposures of bone previously. Most of the bone we were finding was fragmentary and did not go far under the surface, a common frustration in the Chinle, but rule #7 is that if something catches your eye, you must examine it. So that afternoon, after prospecting for a while I started walking back to where Rachel was working on an aetosaur osteoderm, and something caught my eye. In the Chinle of PEFO, highly weathered bone is typically a dark purple or maroon, but what caught my eye was much lighter in color - a good sign. I started digging, and digging, and digging, and before long I had uncovered a complete phytosaur cranium. What had caught my eye turned out to be the parietals. Since it was getting late and the skull was so big, we would have to come back another day to finish excavating it and collect it. We dug a drainage ditch and covered it with a plastic bag. We'd be back.

Week 8
A metoposaur clavical with many other small bones.

Many of the small bones I found at Zuni Well Mound.
On Monday, we found out that we would have to leave the skull where we had found it for a little while. We would have to return to the skull to bury it and mark it in a way that would protect it and make it easy to return to in a few months. With that disappointment, we decided to take a slightly different approach to our field work that week. We headed out to a spot called Zuni Well Mound to quarry. It was a very productive microvertebrate site, but the bones were very fragile. It seemed like even looking at them would make them disintegrate. Despite that we were still able to collect a lot of material including metoposaurs, Vancleavea, fish, and even a partial dinosaur pes. It was mid week when we were finally able to go back out to bury the phytosaur. As we were leaving we decided to stop at a location that Berkley (in the 1980s) had nicknamed "Angry Man Flats" after a rancher had yelled at them for being there (even tho the land was technically BLM land and Berkley had a permit). Bill located an area that had a lot of surface bone. It seemed to be all coming from a single layer. A bonebed? We had to call in Kenny to bring us more supplies, but by the time he arrived we had found that a lot of the bone too weathered and did not go far under the surface. Kenny was not happy that he had been pulled out of the lab for this (leading to the new nickname of "Angry Kenny Flats"). We were still able to leave with several small jackets with the intention of returning.

Week 9
Prospecting on state land. Left to right: me, Zach, Sarah, Rachel, Matt, and Chuck (Photo by Andrea Thomer).
Most of the park employees had mandatory training for several days, but luckily we had some visitors to keep us busy. Matt Brown, former PEFO collections manager and current UT Austin collections manager, was in the area to do reconnaissance for next year's field season. Sarah Werning with assistant Zach Morris were in the area collecting herps for Berkley. We spent several days out prospecting on state land - the interns, our visitors, and Andrea (summer intern in the PEFO collections). We found enough bone to make it a good field site for UT Austin. Unfortunately we kept getting chased out by the monsoons. 

One more week to come (including Ghost Ranch), so stay tuned.

And check out Andrea's blog on digitization!

1 comment:

  1. Phytosaurs and nimravids definitely are interesting, and I don’t think they get the popular attention they deserve. They are every bit as weird and wonderful as their more well-known counterparts, but I think part of that problem deals with historical science.