Sunday, January 23, 2011
Anyway, sometime in the next week or two, the February issue of Palaios will be published, which includes one of my first published articles: Mammalian bite marks on juvenile fur seal bones from the late Neogene Purisima Formation of Central California, by myself and Frank Perry of the Santa Cruz Museum of Natural History.
To view the abstract of the forthcoming article, go here. Once the article comes out, I'll have a less technical summary of it posted here at coastal paleo.
Tuesday, January 4, 2011
Chris takes burlap strips back to the excavation. I quite like this photo.
A beautiful sunset (and advancing rainclouds) heralded our completion of the excavation.
The odontocete skull is halfway jacketed, and as the temperature begins to drop, our hands were beginning to go numb.
Chris cuts more burlap strips for the second half of the jacket.
Monday, January 3, 2011
By the middle of the afternoon, we had excavated a ring shaped hole around a cylinder of rock which contains the skull. A few pieces broken off (and glued back on) indicated that the skull was very well preserved. However, given the remaining amount of rock, I was concerned that we would not be able to finish before 5pm. Additionally, while excavating on the left side of the hole, I split off a piece of rock which contained a fragment of the rostrum. This indicated the rostrum was relatively long - a scary prospect, perhaps meaning I would have to return and finish the excavation the following day.
Here's the posterior braincase exposed: the right side of the skull is exposed, and the skull is upside down. The right squamosal, and occipital condyle are clearly visible in this photo.
After continued trenching around the cylinder of rock, at about 4pm, the base of the pedestal snapped unexpectedly, and the whole thing came out in one fifty pound piece. The anterior end of the pedestal terminated against an oblique fracture surface; I was nervous that the rostrum may have continued through this fracture. I carved off a half-inch from this surface, and found no bone; additionally, I found no bone in the end of the pedestal. Fortunately, this means the entire skull is preserved within the block.
Saturday, January 1, 2011
Here's a closeup view of the specimens.
Chris Pirrone applies vinac to the fossil vertebrae.
We collected these three vertebrae, but it was too cold to stay and dig through the sediment for more bones. I'm sure there are more; some forelimb or cranial elements would be great. I'll return to the locality once some more storm activity cleans off the cliff exposures.
During the course of my taphonomic research of fossil vertebrates in the Purisima Formation, I've found that associated vertebrate remains (two or more elements which in life are only joined by soft tissue) are extremely rare in the shallow marine fossil record (if the Purisima Formation is taken to be a representative shallow marine deposit). Indeed, this is one of a couple dozen specimens showing any degree of association or articulation.