Wednesday, 5 November 2014

A Dinosaur Mystery: The Case of the Freakish Forearms

Paleontology is an art as much as it is a science. When the animals you study mostly died out around 65 million years ago it can often be tricky to understand the most basic things about them. For that reason, paleontologists can be prone to some of the most imaginative theories in all of science. That is to say, sometimes they just make stuff up. Not that you can blame them. Dinosaurs especially are just one of those things that people are really excited to learn about. In the world of science, when you’ve got everyone’s attention, it is tempting to come up with a good story to tell, even if it isn’t always supported by the facts.

A few famous and notable mistakes made since the study of dinosaurs began include the Iguanadon’s spiked thumb being placed on its nose as a horn; the discovery and unfortunate naming of the BasiloSAURUS, which is actually an ancestor of whales and not even close to a dinosaur; and the idea that Brachiosauruses spent most of their time underwater with their heads poking out of the surface to breath. 

To be fair to modern paleontologists, most of the really big goofs happened in the early years of bone hunting and things are a little more reserved and a little more open to debate these days… Most of the time, anyway. One exception is the dinosaur known, inconveniently, as Deinocheirus mirificus (we will stick with DM for short). The problem with old DM is that when it was discovered in the 1960’s all that scientists could find were its two front limbs, but oh what front limbs they were. Muscular and measuring 2.4 meters (8 feet) long, ending in three mean looking claws they were unlike anything ever before seen on a dinosaur. Since the arms were all they had to go on, DM’s name literally means “unusual, horrible hands.”
Since it was unearthed, paleontologists have been theorizing what DM could have possibly looked like. Some of the more fun ideas include A) a T-rex-like predator with freakishly long arms to grab fleeing prey and B) something like a reptilian sloth that used its strong arms to hang from tree branches. The ideas were so imaginative and so varied that it was clear to even the casual observer that the people involved really had no idea what they were talking about, which is why DM has spent the last half century in the dusty storage closet paleontology reserves for its cold cases.
And in that closet DM stayed until August of this year when researchers published a paper reporting that, at long last, they had discovered a complete DM skeleton. Finally, crazy notions could be set aside and DM could be marveled at and respected for the impressive, chiseled work of nature it was. Unfortunately for DM, when asked to describe the discovery, lead researcher Yuong-Name Lee said “It turned out to be one of the weirdest dinosaurs. It’s weird beyond our imagination.” Other researchers have commented that “… it’s just so freaking weird – we never would have expected this animal to look so bizarre.” Maybe it’s time to change the name to Rodney Dangersourus.

It turns out that DM was huge. Something like 11 meters (36 feet) long and weighed as much as 6 tonnes. It had a hump on its back, a beak, and hooved feet. Scientists now believe DM lived in wetlands and the contents of its stomach suggest it ate mostly plants and fish. And the arms? It is now thought that they were used to dig through the prehistoric muck in search of good plant-matter to munch on. So much for snagging fleeing prey at high speeds.

So what is the lesson in all of this? Something we thought might have been the baddest predator of it’s time turned out to be a muddy swamp-monster. Yeah, that might be one way to look at it. The other, much cooler lesson is that dinosaurs still have the ability to surprise the best minds in the business. When you can shock a profession as imaginative and outlandish as paleontology (did I mention they used to think stegosaurus had a second brain in its butt?) you are certainly from a ilk worthy of our attention. In the end, it goes back to a great quote from geneticist J.B.S. Haldane: “My own suspicion is that the Universe is not only queerer than we suppose, but queerer than we can suppose.” Or, if you prefer, another quote from the fictional scientist Dr. Ian Malcolm: Just when you think that nature can’t get any more screwy, “life finds a way.”