Updates from the Vertebrate Paleontology Lab

Happy New Year, and more from the collections

Fri, 2 Jan 2009 14:23:33 -0500

I hope everyone has had a pleasant holiday season. I’m still on vacation, but return to work for a very busy period next week. The museum’s annual Dino Day festival is scheduled for January 10, which is also the day that the Boxley stromatolite goes on exhibit. I also have to start some of the detailed planning for upcoming excavations at Carmel Church and Wyoming, and for the 2009 meeting of the Southeastern Association of Vertebrate Paleontology (there is a link to the meeting information on the blog home page, but the site is still under construction).

In the interim, here’s another specimen from the collections. This one’s from Carmel Church, and was collected by Paul Murdoch in 2003. This is a partial dentition of the eagle ray Myliobatis, like these modern examples of M. californica at Sea World:

Fossil Myliobatis teeth are fairly common on the Atlantic Coastal Plain. The remarkable thing about this specimen is that it remains the only definite Myliobatis specimen ever found at Carmel Church, even though the rays Aetobatus and Aetomylaeus are fairly common.

Red Mountain

Tue, 23 Dec 2008 22:20:20 -0500

Tim and I spent last night in Birmingham, Alabama, and we had to get an early start this morning. But when I found out that our hotel was only 3 miles from the statue of Vulcan, I couldn’t help but make a brief stop.

Birmingham was founded in 1871 specifically as a center for steel production. In recognition of the city’s history, for the 1904 World’s Fair Birmingham Steel and Iron Company produced a 56-foot-tall cast iron statue of Vulcan, Roman god of the forge. After long periods of abuse and neglect, the statue was eventually restored and now stands atop a stone pedestal in Vulcan Park on Red Mountain in Birmingham.

Being a geologist, I couldn’t help noticing the bright red bricks that form Vulcan’s pedestal, visible at the bottom of the photo below:

That started me looking at the stone paths and stairs leading to the statue. These turned out to be blocks of heavily-rippled sandstone:

There is quite a lot of variation in these blocks, but many of them are deep brown to red, due to high concentrations of iron. In fact, these are part of the Red Mountain Formation, a fossiliferous Silurian unit. Among the species known from the unit is the large brachiopod Pentamerus, such as these specimens on exhibit at the Smithsonian:

The Red Mountain Formation is actually so high in iron that it can be used as an ore; it was the source of the iron used to cast Vulcan. The presence of this rock was the reason Birmingham was founded in the first place, making it the inspiration for the statue of Vulcan, the source of the iron used to build him, and the source of his sandstone pedestal.

More aviation, and cephalopods

Mon, 22 Dec 2008 22:49:54 -0500

Sunday we spent the day at the National Museum of Naval Aviation in Pensacola. The Navy has a long history of research in geology, meteorology, and oceanography, all of which have an important influence on naval operations. One of the aircraft in open storage behind the museum is the prototype Lockheed P-3 Orion. During the 1970s NASA used this aircraft for various geophysical research, including magnetic mapping of the Arctic Ocean.

Below is a Lockheed WV-2, which was used by the Navy as a hurricane hunter in the 1950s and ’60s. This role is now performed mainly by National Oceanographic and Atmospheric Administration P-3s. The prototype of the WV-2 was (not surprisingly) the WV-1; my grandfather was a mechanic on the WV-1 when it was undergoing testing at Patuxent River Naval Air Station in the early 1950s.

And now, back to critters. I think cephalopods are possibly the most intriguing invertebrates out there (no offense to all those folks working on other invertebrate groups). Besides their intelligence, they have remarkable camouflage abilities. This cuttlefish at the Georgia Aquarium seemed content to try to intimidate me through the glass (although it does seem to change color at one point):

This octopus at the Dauphin Island Estuarium, on the other hand, decided to try to hide from me, matching both the background color and texture:

This octopus was either inexperienced, or wasn’t trying very hard, because when they want to octopuses can disappear (there are several YouTube videos showing this). Besides being able to match its colors to the background, an octopus can also change its shape to match textures, as the only hard part of its body is the beak. Of course, this means that the octopus has no fossil record, as far as I know.

Given their impressive abilities, it’s no wonder that cephalopods were the subject of Monday’s xkcd comic:

Aquariums

Sat, 20 Dec 2008 20:15:52 -0500

Tim and I have visited several aquariums on our road trip. A few days ago we stopped at the Georgia Aquarium, which is best known for its huge main tank that holds four whale sharks, as well as a manta and several thousand other fish. Whale shark teeth are known from the Calvert Formation, although we’ve never identified them at Carmel Church (so far). Even as large as whale sharks are, as filter feeders their teeth are tiny. We spent the day at the aquarium, and were able to see a whale shark feeding late in the afternoon:

This afternoon we stopped at the Dauphin Island Sea Lab Estuarium. Dauphin Island is a small barrier island at the mouth of Mobile Bay in Alabama. The Sea Lab does a lot of oceanographic work in Mobile Bay and the Gulf of Mexico, and includes the Estuarium as part of their educational effort. I have to say it was probably the finest small aquarium I have ever visited, with a huge amount of both fish and information packed into a tiny space. We stayed several hours, but I could have easily spent a day there. Two of the more interesting specimens (at least to me) included a black drum (Pogonias, top), and a red drum (Sciaenops, bottom), both of which are known from Carmel Church:

As a final bonus, while on Dauphin Island we stopped briefly at Fort Gaines, a Confederate fort that guarded Mobile during the Battle of Mobile Bay. I mention it here because parts of the original fort walls were built of indurated shell beds that are most likely Pleistocene in age:

U. S. Space and Rocket Center

Wed, 17 Dec 2008 20:48:19 -0500

OK, it’s not paleontology, but it is relevant to the study of Earth’s natural history. After a brief stop yesterday at the Gray Fossil Museum (the site of the 2008 SeAVP Meeting), Tim and I continued our road trip today by heading to Huntsville, AL, to visit the U. S. Space and Rocket Center (incidentally, you get free admission with VMNH membership, which saved us $35).

It’s easy to forget how critical the space program is to understanding Earth systems, although I received a gentle reminder as I used the GPS on my iPhone to navigate across northern Alabama. Satellites have only been around for 50 years or so, and there have only been significant numbers of them for around 30 years. When I was an undergraduate GPS was the exciting technology on the horizon, and it has since revolutionized mapping.

Satellites are the primary means of studying ocean productivity patterns, which are so important to marine mammal evolution (among other things). Our knowledge of ocean and atmospheric circulation was sketchy at best prior to satellite observations. As recently as World War II, three U.S. Navy destroyers were lost in a single night when they plowed through a typhoon; it’s impossible to imagine such a thing happening today.

The connections between the space program and earth science goes on and on. Current hypotheses about the early (pre-Archean) history of the Earth are partly based on the geochemistry of rocks recovered from the moon; ancient river courses can often be seen directly in satellite photos; features such as past wave-cut benches that could previously only be identified through painstaking mapping can be spotted easily by satellite. In my introductory geology classes students do five different lab activities that require Google Earth. In fact, last summer before I headed to Wyoming I used Google Earth to help me remember the exact path to the Two Sisters site, by locating and following the tracks from our previous excavations.

Visits like this serve as a nice reminder of the interconnectedness of science. All of us really are working on a web of knowledge to explain the history of the universe and how it works, and there are an infinite number of places where our branches of study are linked together. One of the attractions of paleontology, at least for me, is that it is a kind of science crossroads where numerous specialities meet; that makes for exciting and intellectually stimulating work.

After leaving Huntsville, Tim and I drove to Atlanta in constant rain; but I knew it was coming, because I had seen the satellite images of the storm clouds at the Space Center.

Virginia Living Museum

Tue, 16 Dec 2008 09:06:19 -0500

The last stop on my swing through eastern Virginia was the Virginia Living Museum in Newport News, which had requested help identifying some of the vertebrate fossil remains donated to them over the years. The highlight of their collection is the complete walrus skull shown above, which was pulled up from the seafloor by a scalloper off the coast of Virginia. VLM actually have quite a few walrus remains (mostly tusks) in their collection.

Some other goodies:

Isolated periotics from a small odontocete, apparently both from the same taxon (they have periotics from several different species):

Tympanic bullae from a right whale (left) and a balaenopterid (right):

A possible tooth from the giant beaver, Castoroides ohioensis (I’m not as sure about this one):

A mystery fossil; feel free to speculate. I’m leaning toward a seal humerus, but I’m far from convinced:

Tim and I are going on a road-trip vacation for the next week, but I will be posting updates from the natural history parts of our trip.

William and Mary

Sun, 14 Dec 2008 20:49:53 -0500

I spent Sunday in Williamsburg at William and Mary, helping to identify a number of bones found along the James River. The deposits along the James are mostly late Miocene Eastover Formation, and early Pliocene Sunken Meadow Member of the Yorktown Formation. Isolated bones (mostly whales) are frequently found along the river banks.

The specimen at the top of the page is part of the base of a baleen whale skull (mostly the basioccipital); this is a ventral view, with the front of the skull toward the top. The two knobs of bone are called the basioccipital crests.

The bone below is also from a baleen whale. These are the first two cervical (neck) vertebrae, fused together, seen from the front in the first image and from the top in the second:

This is a rather unusual pattern. Normally, baleen whales do not show any fusion of the cervical vertebrae. The main exceptions are the balaenids (right whales), which are known from the Sunken Meadow, but in balaenids all seven cervical vertebrae are fused together. I suspect this is more likely from a balaenopterid whale, with a pathological fusion of the two vertebrae.

Garber Facility

Fri, 12 Dec 2008 19:36:03 -0500

After giving a lecture at the Caroline County Visitor Center last night, I drove to Suitland, Maryland. This morning I was joined by Brian Beatty from NYCOM, and we headed over to the Smithsonian’s Garber Facility, where the whales (among many other things) are stored. Both the modern and fossil whales are stored in two warehouses, and the number of specimens is stunning. One of the most impressive is an enormous blue whale. Here’s the skull (with Brian for scale):

The lower jaws:

Here’s a right whale skull (the arched rostrum is typical of the right whales):

 Charlie Potter, John Ososky, and Erich Fitzgerald from the Smithsonian were also there, helping us find specimens and pointing us to things we weren’t aware of (that’s Erich holding the whale, with Charlie in the background):

The whale Erich’s holding is a pygmy right whale, Caperea marginata. Caperea is the smallest living baleen whale, and is a very strange animal that is rather dramatically different from any other known baleen whale.

Brian is a crazy man who runs around sticking his fingers into the back end of any whale skull he sees, no matter how juicy they are. He claims that there’s a scientific reason for this, but there are limits to what I’ll do for science.

We were actually there to work on the Carmel Church baleen whale. One goal was to compare it to the type material of Diorocetus hiatus. Here is our skull, mostly complete:

And here’s the type Diorocetus hiatus:

One feature of the Carmel Church specimen that I had believed was fairly unique was the expansion of the tip of the lower jaw...

...but it turns out that Diorocetus has the same feature, strengthening our initial assignment of the Carmel Church whale to this species.

It turns out that Diorocetus also has the dense ribs that are found in the Carmel Church specimen:

We spent a productive eight hours at the Garber Facility. Tomorrow Brian heads back to New York, while I’ll drive to Williamsburg to look at more whales.