Assorted Paleo News of the Day

I may or may not be able to get to all this stuff in detail today, but here's a smattering of some paleo news to start your day with;

• Paleontologists have known for a number of years that the Chicxulub crater in the Yucatan peninsula is likely the "smoking gun" for the end-Cretaceous meteor impact, but new research suggests that the bolide struck the earth in water deeper than originally thought. This would modify ecological effects in the wake of the impact, and it was good to read that a variety of short-term and long-term effects of the event were considered in the new research;

[Sean] Gulick says the mass extinction event was probably not caused by just one mechanism, but rather a combination of environmental changes acting on different time scales, in different locations. For example, many large land animals might have been baked to death within hours or days of the impact as ejected material fell from the sky, heating the atmosphere and setting off firestorms. More gradual changes in climate and acidity might have had a larger impact in the oceans.

The research has been published in the new journal Nature Geoscience ("Importance of pre-impact crustal structure for the asymmetry of the Chicxulub impact crater," by Gulick, et al.)

• In case you missed it, news of medullary bone in dinosaurs has been causing quite a stir as of late (Darren covered it here). This sort of research opens up all sorts of new questions, especially since there now seems to be a good marker for determining the sex of dinosaurs (medullary bone is a consequence of egg formation, the presence of this type of bone signaling that the dinosaur was probably female). I'm sure we'll be hearing more and more about this research as new specimens come to light and old specimens are re-evaluated, but for now you can check out the press release and the PNAS paper.

• Remember that mammalian supertree published last year in Nature that suggested placental mammals emerged during the Cretaceous before the K/T extinction and then diversified later? A new paper published in PLoS by Kitzoe, et al. refutes this view by suggesting that increased rates of evolution have thrown off molecular time estimates for the origin of placentals, the new research appearing to reconcile molecular data and paleontological evidence. [Hat-tip to Will and Michael]

• Someone was asleep at the switch over at Yahoo!News. While the basic fact that a number of fossils are going up for auction in Paris in April, I don't know whether to laugh or cry about some of the mistakes made in the short piece. A mosasaur skull is said to belong to a "Mosasaure," the Triceratops is said to be a "four-legged triceratops" (you know, because there are all those two- and three-legged species out there), sabercat skulls are "sabre-toothed tiger" skulls, Edmontosaurus is a "duck-beaked dinosaur," and the article cites a "tyrannosaurus egg, mineralized in agate," which has been valued for the low, low price of "20,000 and 25,000 euros."

• It's the 2nd blogiversary of Tetrapod Zoology! If you're not already reading Darren's well-researched and highly-informative posts, you should be.

• What's a collection of links without a shameless plug or two? The next edition of The Boneyard will be up tomorrow over at The Dragon's Tales, so get those links to me or Will soon!