dinosaurs
laelaps | January 14, 2008
The trailer for the film The Land That Time Forgot.My first impression of what a dinosaur was conjured up images of creatures impossibly big and toothy, real-life monsters with names that sounded like they could very well have been out of mythology rather than science. I didn't know that they weren't supposed to drag their tails or that they had been moved out of the swamp by the Dinosaur Renaissance; all I needed to know was that they were creatures that lived and died a long, long time before I was born, even though my imagination didn't let them rest soundly. I know a lot more about…
laelaps | January 14, 2008
According to USA Today, a number of dinosaur tracks have been found in the Washington, D.C. area by amateur paleontologist Ray Stanford. Stanford has also found including a potentially new species that he will announce with Johns Hopkins paleontologist David Weishampel in the near future, although for now all that is being said of the find is that it's a kind of "Cretaceous Roadkill."Greg has the scoop on potential evidence for the "island effect" in Thecodontosaurus. He was kind enough to send me to paper ("The age, fauna and palaeoenvironment of the Late Triassic fissure deposits of…
laelaps | January 11, 2008A lot has been said as of late about reconstructions of dinosaurs and other prehistoric creatures on various blogs, and I'm not one to keep my mouth shut on the issue. I'll put up my own take on the issue tomorrow, but for now here's some Tyrannosaurus Alan spots that'll help set the stage;
laelaps | January 11, 2008A female gharial (Gavialis gangeticus).
Ever since Baryonyx walkeri was announced to the scientific community in 1986, spinosaurid dinosaurs have often been compared to crocodylians (at least as far as the construction of their skulls are concerned), the similarity going so far as to result in one African spinosaurid receiving the name Suchomimus ("crocodile mimic"). In the latest issue of the Journal of Vertebrate Paleontology, however, Rayfield et al. put such comparisons to the test to see if spinosaurid dinosaurs had bites that were functionally similar to living crocodylians.
The snout…
laelaps | January 9, 2008The skull of Psittacosaurus. From Osborn 1923.Despite the large amount of evidence that birds are the direct descendants of a group of theropod dinosaurs some researchers continue to protest the association, one of the most vocal opponents of the idea being Theagarten Lingham-Soliar. Working with Alan Feduccia and Xiaolin Wang (two other outspoken critics of the same topic), Lingham-Soliar published a paper last year proposing that the "protofeathers" on the fossil Sinosauropteryx were collagen fibers and not feathers at all. I didn't buy the hypothesis (see this summary for an excellent take…
laelaps | January 4, 2008Non Sequitur replays the evolutionary tape with interesting results...
[Hat-Tip to Michael]
laelaps | January 3, 2008Sometimes I feel like I'm watching scientists concerned with the end-Cretaceous extinction (the one that killed off all those nifty non-avian dinosaurs and other animals) engage in a more formal version of the Monty Python "Argument Clinic" Sketch. Some that favor the impact of a comet or meteor of being the "smoking gun" accuse their opponents of being grumpy old uniformitarian fundamentalists, while some that favor a more gradual extinction that was mostly over by time the extraterrestrial body hit the earth say that the other side is made up a bunch of catastrophists that wouldn't know a…
laelaps | December 31, 2007
When I was a kid nearly every dinosaur book and documentary had at least one common phrase that was uttered over and over again; "Dinosaurs have been found on every continent, except Antarctica." By 1986, though, this could not longer be stated as the ankylosaur Antarctopelta oliveroi was discovered, with the large theropod Cryolophosaurus ellioti being uncovered in 1991 (subsequently named in 1994). While its phylogenetic position is still undergoing scrutiny (at present it appears to be the oldest known tetanuran theropod), Cryolophosaurus is impressive as it was a very large (about 20-26…
laelaps | December 30, 2007
As much as I love the mount of Barnum Brown's famous Tyrannosaurus skeleton at the AMNH, one of my absolute favorite reconstructions is the one pictured above from the Maryland Science Museum in Baltimore. While many Tyrannosaurus mounts have their heads high up in the air, perhaps even with jaws agape looking down at visitors, this skeleton's skull is close to the ground and allows for an excellent look at the marvelous osteology of the great head of this dinosaur (as well as giving me the impression that the skeleton is just as curious about me as I am about it, were it alive that is).
laelaps | December 24, 2007
For those of you who haven't seen the Barosaurus mount at the AMNH, the adult skeleton is rearing to protect a juvenile from an Allosaurus, and this is the skull of that juvenile. I don't know how much material from it was actually found (not yet, anyway), but as you can see it's a bit dusty. Strangely enough, most of the exhibits at the museum were infested with dust bunnies or otherwise coated with a fuzzy covering of gray. Maybe I should try to get in on the ground floor in the style of Roy Chapman Andrews (who started at the museum as a janitor) by offering to dust the mounts...
laelaps | December 23, 2007
A light in the ceiling illuminates the holes in the skull of the towering Barosaurus mount in the Grand Rotunda of the AMNH. The trip into the city yesterday was tiring, but it was definitely a lot of fun, especially since I got to hang out with my fellow dino-nerd Amanda (and her boyfriend) in one of the best museums in the world. Amanda and I also got to chat with one of the "Fossil Interpreters" at the museum for a while, and it was definitely nice to chat with someone who knew a lot about the exhibits (Here's a tip if you visit the museum yourself; look carefully at the ribs on the left…
laelaps | December 17, 2007
A beautiful Barosaurus lentus by Michael Skrepnick. Click the image to see it full size.A little over a month ago I shared a beautiful black & white drawing paleo-artist Michael Skrepnick created for the unveiling of "Gordo," a long-lost Barosaurus lentus that has now gone on display at the Royal Ontario Museum in Canada. Now Mike has graciously allowed me to post his absolutely gorgeous colored version of Barosaurus, an very wonderful reconstruction, indeed. Unfortunately for those in the area of the ROM I wasn't able to post this sooner as there was a big event this past weekend, but…
laelaps | December 16, 2007
Camarasaurus is a bit of an under-appreciated sauropod, not being nearly as famous as Apatosaurus, Brachiosaurus, Diplodocus, or a number of others. Still, during a recent visit to the AMNH I was struck by something about its skull that I hadn't noticed before; it has some very big holes. While it might be difficult to tell from this angle, the skull of Camarasaurus has a very large orbit and a very large nasal area, the bony struts running between the holes being relatively thin. While I'm not suggesting a direct evolutionary relationship, it did remind me of the skull construction of the…
laelaps | December 13, 2007Over the past two decades there has been an explosion in the number of large theropods that have been discovered (or as we shall see, rediscovered) in Africa and South America, the predatory dinosaurs of what was once Gondwana being just as large and terrifying as their more famous Northern Hemisphere counterparts. Abelisaurids (i.e. Carnotaurus, Rugops, Majungasaurus), Spinosaurids (i.e. Baryonyx, Suchomimus, Irritator, and Spinosaurus), and Carcharodontosaurids (i.e. Giganotosaurus, Tyrannotitan, Mapusaurus, and Carcharodontosaurus) have all emerged from the rock at an alarming rate,…
laelaps | December 13, 2007
I've already written something up about the infamous "Dinosauroid" previously, but it is funny how we're told that if the non-avian dinosaurs didn't become extinct 65 million years ago (preventing mammals as we know them from evolving, the clip says) humans would still have been around to take advantage of a warm Protoceratops omelettes, the dinosaurs themselves being essentially unchanged. Indeed, it seems that it's hard for us to imagine a world without something like ourselves in it, the dinosauroid being an extension of the somewhat teleological or vitalistic premise that humans are "…
laelaps | December 11, 2007A mount of Plateosaurus. [Source]When I was first becoming acquainted with dinosaurs, the origin of the gigantic Jurassic sauropods seemed pretty straightforward. There was Plateosaurus (see above) from the Late Triassic of Europe, and it almost seemed certain that it was the ancestor to behemoths like Diplodocus and Brachiosaurus that were present in every dinosaur book I owned. What has become apparent, however, is that the evolution of sauropodmorph dinosaurs is not nearly so simple, and the animals once considered to be the ancestors of the later "earth shakers" are more likely a sister…
laelaps | December 7, 2007Paleontologist Jack Horner has proposed that the pachycephalosaurs Dracorex (upper left) and Stygimoloch (upper right) are really growth stages in the species Pachycephalosaurus (lower center), as presented in the November 23rd, 2007 issue of SciencePachycephalosaurus was always introduced to me as the ancient equivalent of a Bighorn Sheep (Ovis canadensis), always looking for some excuse to bang their heads together. As I grew older I didn't really buy the head-to-head butting hypothesis, especially since the heads of these dinosaurs were domed and did not provide a wide, flat space to…
mikethemadbiologist | December 5, 2007No, it doesn't eat brains: that would be a fossil zombie dinosaur. From The Washington Post:
A high school student hunting fossils in the badlands of his native North Dakota discovered an extremely rare mummified dinosaur that includes not just bones but also seldom seen fossilized soft tissue such as skin and muscles, scientists will announce today.
...."He looks like a blow-up dinosaur in some parts," said Phillip Manning, a paleontologist at the University of Manchester in England who is leading the inquiry. "When you actually look at the detail of the skin, the scales themselves are…
laelaps | December 4, 2007George and Charles H. Sternberg's "Trachodon" (=Edmontosaurus) mummy, discovered in Wyoming in 1908. Image from Osborn, H.F. (1912) "Integument of the iguanodont dinosaur Trachodon", Memoirs of the AMNH ; new ser., v. 1, pt. 1-2.Dinosaur "mummies," specimens that have undergone unusual preservation and retain some skin impressions along with the bones, are always exciting when announced, one of the most famous being the "teenage" Brachylophosaurus dubbed "Leonardo." (See here for information from Kodak on Leonardo, as well as this page from the Judith River Dinosaur Institute) This particular…