Wednesday, January 18, 2012

Southern California Research Trip, Part 1: San Diego Museum of Natural History

After a ten day visit with my wife's family for Christmas in Billings, Montana, my wife and I flew back to California, and had two days to get ready for a research trip to southern California with our friend and colleague Morgan Churchill. Except that we both got sick with a nasty two day cold - we got back on a thursday night around midnight, and were supposed to leave on sunday morning (which also happened to be January 1st). Needless to say, neither of us really were able to get ready for the trip on account of how crappy we both felt, and miraculously, waking up on sunday morning for the trip, I finally felt okay to drive, and the trip was a go (only we still had to pack, and didn't get out of town until close to 1pm). It's an 8 hour drive from San Francisco to San Diego (without traffic), so we were looking at a pretty late arrival. That being said, we had just driven up to Montana a couple weeks prior, and 8 hours seemed miniscule compared to two 10 hour days across the American west. We got to Los Angeles around 7pm, and stopped in for a couple hours to visit our best friend, Lee Hall, and his awesome girlfriend Ashley Fragomeni, which was refreshing (and far too brief). We finally pulled into east San Diego to pick up Morgan at about 12:30am (after driving through the densest coastal fog I've ever seen - and that's coming from a San Francisco native!). We pulled up to the house of our gracious host (and my coauthor) Joe El Adli, who also hosted me during the SATLW meeting in June at SDSU.
Morgan measuring a skull of Valenictus chulavistensis, the "toothless" walrus from the Pliocene San Diego Formation.

We had several goals for our visit - Morgan and I are studying a new specimen of the middle Miocene walrus Pelagiarctos, which Larry Barnes descibed in 1988 from the "chin" end of a pair of mandibles and some teeth, and suggested some interesting hypotheses regarding its paleoecology. At San Diego in particular, Morgan needed to spend some time photographing and measuring every pinniped skull and jaw he could (and it took up nearly the entire time of our visit). When not helping Morgan with measurements, I was chatting with Tom Demere (paleontology curator at the SDNHM) and Joe El Adli (lead preparator of the paleo department at SDNHM) about the fossil mysticete Herpetocetus, as well as photographing some earbones and crania of balaenopterids that occur in both the Purisima and San Diego Formations.

A mounted skeleton of Allodesmus (kernensis? gracilis? depends on who you talk to) at the SDNHM, while the tail and claspers of a giant Carcharocles megalodon loom ominously above.

A closeup of the business end of Allodesmus.

A skull of Desmatophoca oregonensis, a smaller and earlier relative of Allodesmus from the Astoria Formation of coastal Oregon. This specimen was collected by Douglas Emlong, and described by Tom Demere and Annalisa Berta in 2002.

Two pinniped skulls in particular that we definitely needed to see are on display in a huge cabinet out in the Fossil Mysteries hall. During my 2007 visit, I had been let into the cetacean display case to examine and photograph a porpoise skull, but that case actually had an entire door and you could walk around in it; this display case with the walruses had a 150 pound sheet of glass that required four of us (Morgan, Joe, myself, and the SDNHM collections manager, Kesler Randall) to use large suction cups to lift the ~7 foot tall sheet off of the case (which required Joe and Kesler to go up on ladders on either side). It was quite the performance, all done prior to the museum opening.

Joe (left) and Kesler (right) brainstorming about removing the sheet of glass from the walrus exhibit.

Joe placing the suction cups on the glass. The two walrus skulls in
- Dusignathus seftoni on the left, and Valenictus chulavistensis on the
right - can be
seen at the bottom of the case.

We needed to see two specimens in particular - one is the nearly complete and well preserved paratype skull of Valenictus chulavistensis, and the other is a referred skull of the dusignathine "double tusked" walrus Dusignathus seftoni. I had really ought to blog about each of these taxa, as they are truly wonderful and bizarre creatures. The new skull of Dusignathus was collected about 6 or 7 years after Tom Demere described and named the species in 1994, and is in much better shape than the holotype specimen, which is substantially smaller, and is missing the palate (although this new larger male specimen is missing the top of the skull). Although I've seen this display several times before, I must admit I was very surpised with 1) how small the Valenictus paratype is in comparison to other skulls, 2) how light the paratype is (Tom stated that it was very poorly mineralized and held together primarily with consolidant), and 3) how damn huge the Dusignathus skull is in comparison to other skulls in collections.

Joe (in brown) and Kesler (left) set the walrus crania down onto foam, while Morgan (right) and I (gray) watch.

While Morgan was taking photos, I decided to get a different angle on some of the fossils while I had a ladder available. Here I am shooting the Allodesmus photos seen above.

Here's a nice shot I got from the ladder of a new species of balaenopterid mysticete from the Pliocene San Diego Formation (this taxon is being studied by SDSU student Jessica Martin). So far as I can tell, I've not yet seen this animal from the Purisima Formation.

A neat mount of a fossilized wing of an albatross, Diomedea sp. (but should probably be identified as Phoebastria sp.). Albatrosses are definitely huge birds - but the partial humerus of Pelagornis sp. I recently published, which was only 1/2 complete, was the same length as the complete humerus of this specimen.

My wife always makes friends on research trips.

By the end of the San Diego visit, we had each taken several gigabytes of photos, and dozens of measurements for our research. My wife had spent a fair amount of time next door at the San Diego Zoo, and at the Museum of Man. We spent wednesday morning at the SDNHM to wrap up everything before driving to LA, where we would spend our first afternoon of research at the Natural History Museum of Los Angeles County (NHMLAC), but known to paleontologists simply as "LACM" - which will be the subject of the next post.

1 comment:

Doug said...

great post. Love hearing about your research, even if I'm throwing in the towel: