Jeopardy! category: DINOSAURS (21-07-2014)
$1600 clue: Scientists classify dinosaurs by dividing them into two groups based on this body part. Some, like the T-Rex, had the lizard type, while the Stegosaurus had the bird type
The gist: OK, this might get a little bit confusing. You know how modern birds are evolutionary descendants of dinosaurs?
Well, they’re not actually descended from the order of dinosaurs called the Ornithischia, meaning “bird-pelvised” (or “bird-hipped,” as we’ll call it here) – birds are actually the descendants of (as well as being modern members of) the order Saurischia, meaning “lizard-hipped.” That’s right. No animal that exists today is “bird-hipped,” taxonomically speaking. Even birds. But of course, that’s just the result of the fact that back when scientists were giving all these orders names, palaeontologists didn’t know very much about what they were looking at – H.G. Seeley first coined the names for the two orders way back in 1888. They were just describing what they say when they unearthed all these humongous hip bones, and to them, the hips of the two-legged carnivores from which modern birds descended looked more lizardy (“sauros” is Greek for lizard, just like in the second part of “dinosaur” itself) than birdy, and today we’re stuck with that backwards naming convention.
The main difference, I should add, between the two types of hips are the direction in which the pubis bone points. In Ornithischians, the pelvic bone points backwards towards the tail, while in the Saurischians it points forward – for more details, you can see this handy page courtesy of UC Berkeley’s Museum of Paleontology.
Luckily, though , it’s not so hard to remember which types of dinosaurs go in which group. Among the Saurischians, you’ll find the two-legged meat eaters like T. Rex and Velociraptor, as well as the gigantic four-legged long-necked herbivores like Brachiosaurus and Diplodocus (plus their lesser known ancestors that were able to walk on two legs, albeit quite hunched over). In the Ornithischia are most of the smallish four-legged herbivores – the horned and frilled ceratopsians, the armoured dinosaurs like stegosaurus and ankylosaurus, and the hunched-over, not-quite-four-legged ornithopds, of which the most famous is the Iguanodon, with its fierce-looking thumb spike.
The clue: Like the last clue, this one benefited quite a bit from the visual element, where the hip bone could be plainly seen (although it of course still needed to be correctly identified). This clue is getting pretty deep in dinosaur morphology, which I love to see anywhere on TV, and especially on Jeopardy!. I can’t imagine anyone would be able to divine the correct response just from knowing there’s a “lizard” and a “bird” type. But of course, no one is supposed to anyway – hence the visuals.
In Jeopardy!: “Pelvis” shows up in 24 clues in the J!Archive, although this is the only one that’s about dinosaurs pelvises. The pelvis is a nice, central part of your body, and so clues about it can go in many directions, but there are some common themes that pop up. One, of course, is mentioning the hip, often used as an informal synonym for pelvis – but the hip can mean more than that, so it’s definitely not a sure thing if hips are mentioned. Aside from that, many clues are about the parts of the leg that attach to the pelvis – the hamstrings, of which there are three, the femur, aka the thighbone (plus its femoral artery), and in one clue the sciatic nerve, also the largest nerve in the human body. More surprising, perhaps, is that Georgia O’Keeffe shows up in four clues about pelvises – she painted Pelvis with Moon in 1943.