Saturday, April 7, 2012

New Zealand Eomysticetidae - first look

Starting in the late 1970's and early 1980's, Dr. R. Ewan Fordyce received a grant from National Geographic to start conducting extensive fieldwork on the South Island of New Zealand in search of Oligocene cetaceans and other marine vertebrates. Incidentally, non-cetaceans such as abundant penguins, sharks, and bony fish were collected as well. This fieldwork was not limited to the Oligocene, but also included forays into Paleocene, Eocene, and Miocene localities. Over the past 30 years, Ewan has established a massive collection with an astonishing number of beautiful cetaceans. Not only are these fossils beautiful in terms of their preservation, but many of them are extremely bizarre, and the assemblage as a whole includes squalodontid, squalodelphinid, ?dalpiazinid, kentriodontid, and waipatiid odontocetes, as well as several types of baleen whales (toothed mysticetes, Mauicetus and similar "cetotheres", eomysticetids, and others), and even late surviving archaeocetes. Some of these cetaceans have been described, including Waipatia and an eocene archaeocete (Zygorhiza sp.), and several other taxa are on their way to being described.

I first met Ewan in 2005 at the SVP meeting in Arizona, and I vividly remember watching him discuss how to excavate fossil whales with a chainsaw, of all things; I immediately thought it was too extreme of an excavation method for me, but after I saw it in action last monday in the field (ironically, at the same quarry the photographs from the 2005 presentation), I immediately decided I would bring this method back to the United States. In fact, it was quite funny after watching him rev up the chainsaw - an adrenaline-inducing activity in and of itself - and afterwards stating in a polite Kiwi accent "that should clean up quite nicely".

But I digress - prior to graduation from Montana State University last spring, I contacted Ewan about a Ph.D. project, and he suggested studying the large collection of eomysticetid baleen whales from the Kokoamu Greensand and Otekaike Limestone that he had established. I remembered his talk from the 2006 SVP meeting in Ottawa, part of which included a slideshow of beautiful new fossil eomysticetids. I was pretty shocked to have been offered such a beautiful (and large!) collection of fossils to study. The family Eomysticetidae was named by Al Sanders and Larry Barnes in 2002 to accommodate the new taxon Eomysticetus, which is the most primitive described toothless baleen whale (i.e. baleen-bearing baleen whale, if that makes any sense, as opposed to a toothed baleen whale). Previously, the most primitive toothless mysticetes were some of the "cetothere" whales described by Remington Kellogg from the Chesapeake Group on the east coast, AKA "Kelloggitheres"; these however were much younger than any toothed mysticete (such as aetiocetids), and there was an apparently substantial morphological gap between toothed mysticetes and Kelloggitheres. My job is to fill a bit more of this gap in with more eomysticetids from the southern hemisphere- and so far, none of them seem to be identifiable as Eomysticetus, and there are probably several new genera and species represented.

Ewan Fordyce also took on another student recently, which was a total surprise for me. Even when I first got here, it sound like it would be several months away; instead, the new student arrived only two weeks after I did, and even stayed in the same temporary apartment my wife and I stayed in the first week we were here. Cheng-Hsiu Tsai, who goes by just 'Tsai', will be studying the other big group of fossil mysticetes from the Oligocene of New Zealand: Mauicetus and Mauicetus-like mysticetes, which may be the earliest Kelloggitheres. Tsai can be seen inspecting the ventral side of one of the eomysticetid skulls in the above photo.

This specimen, for example, is one of my dissertation specimens: a new taxon, with an extremely narrow rostrum, elongate dentaries, enormous temporal fossae with a long intertemporal region, and really weird squamosals.
Yours truly, examining the extraordinarily freaky squamosals of the specimen.

Tsai, demonstrating the proper way to photograph a mysticete skull.

Yours truly, demonstrating how to use yourself as a scale bar. I am 5'8" tall.
The beautiful skull in oblique view.

Tsai examining the skull. The brass seam on the floor is actually a joint where the floor opens for a small elevator used to bring large fossils up from the basement. On thursday, I spent most of the afternoon lifting a really really heavy plaster jacket a total of about eight feet - this ordeal took about an hour and a half, three other students, Ewan, and our preparator, Sophie. Fortunately, when the jacket is prepared, it will hopefully be a lot lighter when it goes back downstairs.

3 comments:

Rick Ross said...

Looks like you are in early whale heaven!!

Wiki The Great said...

Ewan is one of my lecturers (Basins and sedimentology, 2nd year) and he led the feild trip to the Arthur's Pass region we went on on the 4th of may. Tsai was a demonstrator. Ewan found a monotis fossil and several trace fossils of burrowing animals during the three days, he certainly has a knack for finding old dead things :D And he does have a wicked sense of humor, despite the way he speaks and appears; and Tsai is nice!

Robert Boessenecker said...

I was invited to go along on that trip as I'm still learning local geology; I decided to stay in Dunedin and get a manuscript submitted instead. Ewan does have quite the sense of humor - it's different from what most Americans are used to - but if there's one thing I appreciate in a professor (or adviser), it is a sense of humor.