paleontology
laelaps | April 10, 2009An artist's restoration of Hurdia. From the Science paper.It is not easy working on Cambrian fossils. The petrified treasures are found in only a few places in the world, and even though many exhibit exquisite preservation they come from a time when life on earth would have looked very unfamiliar. One such creature, Anomalocaris, was a three foot long invertebrate that swam by undulating a series of lobes on either side of its body. In front of its mouth were two spiked tendrils that may have helped situate prey items to be processed by its conveyor belt of crushing plates that was its mouth…
laelaps | April 9, 2009
When I first happened upon Sean B. Carroll's new book, Remarkable Creatures my first thought was "Damn! He beat me to it!" For over a year I have been preparing my own pop-sci book about paleontology, evolution, and the history of science, and as I skimmed through Remarkable Creatures I saw that Carroll had already covered a number of the same subjects. I would have been interested in Carroll's book regardless of my own project, but given my goal I knew I had to read it.
Fortunately for me Remarkable Creatures is not as similar to my own project as I had first thought. Instead it is a…
laelaps | April 6, 2009
One of the unwritten rules of creating a good horror yarn is that the location your story takes place in has to be as frightening as your monster. The setting almost has to act an an extension of the bloodthirsty antagonist; a place that can more easily be seen as its lair than a place of human habitation. In Lincoln Child's latest novel Terminal Freeze that place is Fear Base, a rotting military facility shivering the the shadow of Fear Glacier, and it is stalked by something utterly horrifying.
Readers of The Relic, another horror novel penned by Child and his sometimes partner Douglas…
laelaps | April 2, 2009Even if it is only due to repetition almost everyone is familiar with a few geological dates. That the non-avian dinosaurs became extinct about 65 million years ago and the earth is around 4.5 billion years old are figures that are at least familiar to many. (There are a few folks who would prefer to jam the entirety of geologic time into just a few thousand years, of course, but I will not worry over them here.) It truly is wonderful that we have been able to lay out such a detailed map of Deep Time but this was not always so. Today's standard geologic time scale, with all its time…
laelaps | April 1, 2009A model of the skull of Megaladapis From A Guide to the Fossil Mammals and Birds in the Department of Geology and Palaeontology in the British Museum (Natural History).At a meeting of the Royal Society in 1893 the English geologist Henry Woodward read a communication from his Swiss colleague Charles Immanuel Forsyth Major on a new, recently extinct genus of giant lemur from Madagascar. He called it Megaladapis, and it was a lemur with a skull as large a modern gorilla's. Particularly interesting were the thick rims of bone around its eyes which appeared to be oriented slightly upwards.…
laelaps | March 31, 2009A cast of the lower jaw of Dryopithecus available through Ward's Natural Science Establishment.For most of anthropology's history tools had been thought to be the exclusive hallmark of humanity. That only our species could use and manufacture tools was a sign of our superiority, be it the result of evolution or divine fiat, at least until it was discovered that apes could make tools, too. Though anecdotal accounts of tool use by primates had existed for centuries it was Jane Goodall's research at Gombe in Tanzania that truly shattered the "Man the Tool-Maker" image. When told of her discovery…
laelaps | March 30, 2009The "reincarnated" Cohoes Mastodon. You can see him today at the Cohoes Public Library. (From Natural History)For decades we have been hearing of the designs of some ambitious scientists to bring the woolly mammoth back to life. I first heard of such plans in the 1980's when I was a young child but they continue to pop up every now and again. Perhaps we could make a mammoth-like creature through the selective breeding of living elephants or a little developmental engineering, but I doubt that a true Mammuthus primigenius will ever exist again. They are long gone.
It may be that what makes the…
laelaps | March 29, 2009The skull of Dorudon, photographed at the National Museum of Natural History.
clock | March 27, 2009Check out the show's web page:
Fifteen thousand years ago North America was like the Serengeti on steroids, with mega-creatures roaming a continent teeming with incredible wildlife. But then, in a blip of geologic time, somewhere between 15 and 35 magnificent large types of animals went extinct. In a television exclusive, NOVA joins forces with prominent scientists to test a startling theory that may finally explain the Last Extinction, on Tuesday, March 31 at 8pm ET/PT on PBS (check local listings). The program features scientists representing all sides of this debate.
laelaps | March 25, 2009Last week I spent some time writing about Dimetrodon and the various functions paleontologists ascribed to its sail (from a literal sail to a sign of coming extinction). It can be easy to forget that no two sails were exactly alike, though, and paleo-artist Michael Skrepnick (see my interview with him here) was kind enough to remind me of a rather spectacular example of this point.
Two views of a Dimetrodon gigashomogenes with a pathological sail. Courtesy of Michael Skrepnick.Just like any other bones the osteological supports for the sail of Dimetrodon would have been subject to injury and…
laelaps | March 24, 2009Last week I wrote about the shuffling and reshuffling of relationships between whales, hippos, pigs, and an extinct group of mammals called raoellids. One aspect of the paper I did not comment on, however, was the problematic placement of the enormous predator Andrewsarchus.
In November of 1924 Henry Fairfield Osborn described the huge skull of a predatory mammal discovered during a American Museum of Natural History expedition to Mongolia. Unfortunately there was little other than the skull left of the great beast, but Osborn thought it belonged to a gigantic omnivore. Osborn named it…
laelaps | March 21, 2009Maiacetus.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 18, 2009A 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 group…
laelaps | March 17, 2009A 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 creature.…
laelaps | March 16, 2009A 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 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...
gregladen | March 10, 2009 ... has been found. Inside the fish's skull, in fact. This is from a chimaeroid fish, which today are fairly rare but during the Carboniferoius were quite common and diverse. There are really two aspects of this find that are especially interesting. One is the 3D imagery that was obtained of the ancient fossilized brain, and the other is the analysis of the fish's ear canals. The brain is cool just because it is cool (and shows some interesting morphology). The ear canal study is interesting because it shows a pattern different than expected for a fish: This creature was probably…
gregladen | March 10, 2009Dino spoor, that is. A recently reported finding in PLoS ONE clarifies a number of questions about how certain dinosaurs held their front limbs (zombie/Frankenstein-position palm-down vs. huggie-wuggie palms-facing-each-other). This research confirms ...
that early theropods, like later birds, held their palms facing medially, in contrast to ... prints previously attributed to theropods that have forward-pointing digits. Both the symmetrical resting posture and the medially-facing palms therefore evolved by the Early Jurassic, much earlier in the theropod lineage than previously recognized…
laelaps | March 6, 2009The Warren mastodon as originally mounted in the Warren Museum of Natural History. Note the size of the tusks. From The Story of Nineteenth-Century Science.It is rarely crowded in the "Hall of Advanced Mammals" at the American Museum of Natural History. People stroll through on their way to see the dinosaurs and may stop to admire a fossil or two like the striking mount of Amphicyon, but the mammals just cannot compete with the star power of the archosaurs. This is a shame, for not only does the hall hold a weird and wonderful array of extinct creatures, but many people do not realize they…