Bob's Dinosaurs Blog

Appropriately for the July 4th holiday, this last week marked the 100th anniversary of the Tunguska Event--the mysterious explosion over Siberia that (by some estimates) packed the explosive force of hundreds of Hiroshima-sized atom bombs. At the time, in 1908, investigators weren't able to rush to the scene, thanks to the combination of Siberia's remoteness and the paranoia of the beleaguered Russian government (which was less than a decade away from full-scale revolution).

What, exactly, happened in Tunguska? To date, scientists haven't been able to locate a crater, or any other informative residue, so the prime theory points to the detonation of a comet high up in the atmosphere. And why do I bring this up on a dinosaur blog? Well, except for its size, the astronomical body that leveled Tunguska was probably not all that different from the one that wiped out the dinosaurs 65 million years ago. Something to think about before you light that next firecracker!

These days, it seems as if everything is being blamed on astronomical impacts--the extinction of the dinosaurs 65 million years ago, the potential extinction of the human race 10 (or 100, or 10,000) years from now, and (now) the prolongation of the last Ice Age, which wiped out the mammoths as well as the ancient North American Clovis civilization.

According to a new study by researchers at the University of Cincinnati, the earth was just climbing out of its most recent Ice Age 13,000 years ago when a massive comet impact over Canada threw enough dust and ash into the air to block out the sun (and thus lower worldwide temperatures) for another couple of thousand years. The comet is estimated to have been a full mile in diameter, and it would have exploded high up in the atmosphere--which explains the lack of a telltale crater.

Folks in Utah would probably be happier with vast oil deposits, but there's no denying that this state has become one of the world's premier dinosaur destinations--only China has more fossils, and it's not quite as easy to get there. That's why it was interesting to read this opinion piece in The Salt Lake Tribune, in which writer Rebecca Walsh laments the fact that so many of this summer's Utah dinosaur digs will be sponsored by out-of-state institutions (which, naturally, will haul their finds back to museums in New York, Boston, Los Angeles, etc.)

What's to be done? Walsh would like to see more funding for research allocated by the Utah state government, as well as a commitment to a new museum. But, for now, it seems she'd be happy if more native Utah residents went out on digs--and ensured that the bones of as-yet-undiscovered dinos remain within state borders.

Ever since Charles Darwin's day, creationists have tried to cast doubt on the theory of evolution by pointing to the lack of fossil evidence for "intermediate forms"--say, a creature perched halfway between a fish and an amphibian. Well, scientists in Latvia have just pounded another nail into creationism's coffin, with the description of Ventastega, a 370-million-year-old animal that was perched, well, halfway between a fish and an amphibian.

According to the article in Science Daily, Ventastega looked just the way you'd expect for one of the first animals to venture onto land, with its slender, fishlike body and four primitive limbs. Its importance in the evolutionary framework is that it seems to lie midway between an even earlier (and more primitive) tetrapod, Tiktaalik, and the almost contemporary Acanthostega.

Kate Pullen, About.com's guide to rubber stamping, has posted some neat resources for dinosaur stamps. (No, rubber stamping isn't some bureaucratic procedure by which dinosaurs have their immigration papers checked--it's an art form in which intricate designs are etched into rubber, then transferred to paper in colored ink). She's inviting readers to create their own dinosaur stamps, which I'll be glad to feature on this site. So stamp on over and get stamping!

It seems that every one of nature's creatures has its day in the dinosaur-sized record books. I'm not very conversant with beaver paleontology, so I was edified to learn from Discovery.com that beavers the size of black bears prowled North America three million years ago. Apparently, Castoroides ohioensis survived right up to the last Ice Age, when it disappeared along with other plus-sized mammals, like woolly mammoths.

By the way, you'd think these giant beavers would have built Grand Cooley-sized dams, but as far as I know none of these structures (if they existed) have survived down to the present day.

We all know about dinosaurs like T. Rex and Stegosaurus that met their doom 65 million years ago, during the K/T Extinction. But what about the lesser-known dinos that appeared briefly during the Mesozoic Era, only to quickly disperse into the mists of history? I've compiled a Top 10 list of these (completely imaginary) beasties.

By the way, I'd love to have kids draw pictures of these dinosaurs. If you send me a digital file of your child's mythical masterpiece, I'll post it to the site. (Already up: a sketch of the little-known Megalomorphomusometrodon by an eight-year-old girl from Brooklyn.)

Most of the time, paleontology is a lonely, grueling profession, involving long stretches of tedium as researchers painstakingly restore the fragmented tibia of a long-dead dinosaur. Other times, though, it's like going on a paid-for shopping spree at a toy store--as witness the discovery of a huge trove of dinosaur fossils at the Hanksville-Burpee quarry in Utah.

Scientists have yet to take a full accounting of the dinosaur genuses represented in the quarry--a process that may take years--but they've already found the near-complete skeletons of four sauropods, two carnivores, and one Stegosaurus. What's more, all the bones date from a narrow window in the late Jurassic period, which may give paleontologists a detailed view of a typical ecosystem of that time.

Let's face it: Sometimes it can be hard to distinguish a Micropachycephalosaurus ("tiny thick-headed lizard") from a Brachytrachelopan ("short-necked shepherd"), especially if you don't happen to know Greek. For that reason, I've created a list of the Greek words most commonly used to name dinosaurs, along with their English equivalents. As an added bonus, you can use this list to generate your own dinosaur names: be the first kid on your block to lay claim to the rare Megalomorphomusosaurus ("giant mouse-shaped lizard").

Based on its location deep in the southern hemisphere, you'd think Australia would have had lots of dinosaurs in common with South America. In this instance, though, paleontology doesn't follow geology: even though Australia and South America were both once part of the huge southern supercontinent known as Gondwana, investigators have never found the same dinosaur remains on both landmasses.

Until now, that is. According to a story in Science Daily, a research team has caused quite a stir by claiming that an upper arm bone dug up in Australia belongs to a Megaraptor--a carnivore previously thought to have lived only in South America during the Cretaceous period. If this conclusion turns out to be justified, paleontologists will have to do a lot of rethinking about dinosaur migration and evolution Down Under.