laelaps | March 23, 2009
A Cuban crocodile (Crocodylus rhombifer), photographed at the National Zoo.
laelaps | March 21, 2009Hi, everyone. I noticed that many of the people who originally expressed interest in meeting up at the National Zoo tomorrow will not, in fact, be able to make it. As such I have decided to cancel the meet-up tomorrow. Don't fret, though. I hope to be back in the area sometime later this year and I will provide a little more notice about it.
I just hope I will be capable of walking around at all tomorrow. After 9 hours of shuffling around the museums and memorials I don't know if I'll be standing up again anytime soon.
laelaps | March 21, 2009
Maiacetus.
I am having a lot of fun visiting the various museums and landmarks in Washington, D.C. this weekend, and while I don't have much time for blogging I wanted to share a photo from my brief stop at the National Museum of Natural History. Even though I spent most of the day talking to paleobiologists behind the scenes (watch Dinosaur Tracking for details) I did have the chance to briefly check out the new ocean gallery. Pictured above is the skull of the suspended mount of Maiacetus on display in that exhibit.
laelaps | March 21, 2009
The Capitol building, photographed around 7:30 AM.
An earlier attempt at the same photo, taken while crossing the street.
laelaps | March 19, 2009The big news in this week's issue of Nature was the discovery of a small ornithischian dinosaur covered in bristles, but there was another, shorter paper that caught my eye. In December 2007 Nature printed a short communication on Indohyus, a small artiodactyl that seemed like a good candidate for the type of creature that whales evolved from. Paleontologists Hans Thewissen and Lisa Noelle Cooper explain the significance of Indohyus to whale evolution in this video;
There was something that bothered me about the systematic analysis of Indohyus, however. In the paper's phylogenetic tree…
laelaps | March 18, 2009
A very unusual reconstruction of Dimetrodon from the textbook Geology, based on a reconstruction by E.C. Case. Dimetrodon and other sail-backed creatures were once considered to have become too "spiny" to survive.
According to the old, if inaccurate, aphorism ontogeny recapitulates phylogeny, or the development of an individual organism replays its evolutionary history. This idea was seen in the work of various scholars, from Ernst Haeckel to Sigmund Freud, but at the turn of the 20th century some paleontologists thought it could hold true stated the other way. Might the evolution of a…
laelaps | March 18, 2009
Sasha the Amur tiger (Panthera tigris altaica), photographed at the Bronx zoo.
laelaps | March 17, 2009
A mount of Dimetrodon at the AMNH. From the Bulletin of the AMNH.
The predatory pelycosaur Dimetrodon has always been a favorite of mine. Though not a dinosaur it has an appearance as bizarre as any dinosaur you care to name, and the function of the huge sail on its back is remains an enigma. What could such an impressive structure be used for?
Slight differences in the bony back struts of a similar animal that inhabited the same habitat as Dimetrodon provided paleontologist E.D. Cope with a clue. Where Dimetrodon was a large apex predator "Naosaurus" appeared to be a more peaceful…
laelaps | March 17, 2009
A white-tailed deer (Odocoileus virginianus), photographed in suburban New Jersey.
laelaps | March 16, 2009
A visual summary of horse evolution published in 1921 (derived from an earlier diagram by W.D. Matthew). From An Introduction to the Study of Fossils.
When Charles Darwin published On the Origin of Species by Means of Natural Selection in 1859 he faced a substantial problem. His evolutionary mechanism predicted that the fossil record would contain finely-graded transitions revealing what G.G. Simpson would later term the "tempo and mode" of evolution, yet such transitional creatures proved elusive. This was a major problem for paleontologists who believed that studies of European geology…
laelaps | March 15, 2009
Ancestors are important. We like to know where we came from and what sort of legacy our forebears left, but it has only been recently that we have been able to trace the concept of "ancestor" through the depths of geological strata. I may not know the detailed history of my family during the last hundred years or so, but I do know that a number of hominins figure into my family tree.
I am not proud or ashamed of this deeper ancestry which I share with every other Homo sapiens on the planet. It is simply historical fact, but I have to wonder what my education would have been like if earlier…
laelaps | March 14, 2009As I mentioned earlier this month I will be heading down to Washington DC next weekend. On Sunday (March 22) I will be visiting the National Zoo and would love to meet anyone who would like to come by. Let's meet at 11 AM at the dining hall right near the giant panda exhibit (map here).
I apologize if this is not the best time/place for everyone interested in coming by, but it seemed to be the best option (it's going to be a busy weekend!). Just let me know if you plan on coming in the comments and I'll see you next week!
laelaps | March 13, 2009An adult woolly mammoth and offspring, brought to you by the National Film Board of Canada (1979);
I love stop-motion animation, but I have to say the style of this short made me wonder if Rudolph the red-nosed reindeer or the Heat Miser were suddenly going to show up...
laelaps | March 13, 2009I am no fan of the "March of Progress", but I know it isn't going anywhere. It is too readily recognizable as an evolutionary image for its use to be discontinued. That is why I wasn't surprised to see it in a new commercial for Extra spearmint gum. What I was surprised by, however, was that the creators of the commercial think that sloths figured in our evolution somewhere between tarsiers and chimpanzees;
[facepalm]
Creationists don't like the commercial either, but for entirely different reasons. This chap, for instance, is so fervent in his belief in creationism that he feels deeply…