Thursday, February 24, 2011

Return to the thanksgiving odontocete locality

Over winter break Chris Pirrone and I returned to the locality where, a month prior, we had excavated a complete odontocete skull. If you recall, when we collected the specimen we had to excavate and pedestal the skull sideways, rather than the normal way (downwards) that most paleontologists are used to. When I had seen the skull at the end of the summer, it was only a few feet above the sand. I knew that over thanksgiving, there would be a very good chance that the sand would all be gone due to the rough weather which tends to erode away the beaches.

Luckily, at thanksgiving there was a three foot-wide 'rim' of the summer beach left, and closer to the ocean, the beach sand was about 8 feet lower. Fortunately, we had just enough time to collect the fossil. When we returned in January, this sliver had been completely eroded away, leaving the excavation pit about 9 feet above the beach and well out of reach. In the above photo, you can see it about left center.

And here I am pointing to it. It would still have been accessible by ladder, but that would have been a real pain, and I'm pretty sure after standing on a ladder for five hours, it's almost a guarantee that you'd fall off.

Comparison between Thanksgiving 2010 and January 2011. The two photos are taken from nearly the same position (note the rock in the foreground) but the more recent photo is taken from further away from the cliff.

Otherwise, after initial preparation, the fossil appears to be a juvenile Parapontoporia, with a partial dentary, and both tympanoperiotics. The tympanoperiotics are now fully prepared, and were articulated, and sitting above the bony nares and the vertex of the skull (i.e. in contact with the dorsal surface). As the skull was upside down, the earbones must have fallen out, and then the skull rolled over on top of them. I'll have pictures soon.

No comments: