Behold the fearsome Manospondylus: one of the largest, fiercest predators the world has ever seen. With a skull the size of a wrecking ball and teeth like scimitars it terrorized the Cretaceous fens, eviscerating plump vegetarians and kicking around the skinny ones like discarded soda cans. What's that you say? Sounds an awful lot like a T. rex? That's because Manospondylus was T. rex's original name - coined in 1892 before the monster acquired its rather more striking name (in 1905) and started getting into showbusiness.
The mixup is an example of a very basic problem in paleontology: How many species of dinosaurs were there, and how do we know we haven't named something twice? Scientists have named about 1,400 dinosaur species, but slightly fewer than half of those actually merited their classification upon closer inspection. Fortunately, a new study by British paleontologist Michael Benton suggests that we're getting better at catching these mistakes.
According to the study, the modern rate of discovering new dinosaur species is a breakneck 30 species per year, about double the previous peak of dinosaur-naming, in the so-called "Bone Wars" of the late nineteenth century. But because paleontologists have discovered very high quality fossil beds - especially in North America and Asia - they're now working with much more complete material. If you've ever had trouble figuring out how many kinds of ducks you're feeding at your local city park, you might relate to the problem paleontologists face. They're usually trying to differentiate species based on characteristic bumps, fissures, and cavities they find on whichever bones someone has managed to dig up.
Imagine trying to tell a mallard from a pintail based only on the shape of its kneecap, and you get an idea what they're up against. Manospondylus was named from two large but shattered vertebrae, while the first Tyrannosaurus was named, 13 years later, from a partial skeleton. It wasn't until 1917 that the similarity between the vertebrae in the two separate finds was recognized. As a result of the recent flurry of advances, Benton reports, we may be honing in on a guess of how many dinosaur species there really were. At the start of the nineties we guessed there might be 1,200 species, but after a decade of discoveries and some 300 new species, that figure has risen to perhaps 2,200. With only about 675 "valid" species on the books right now, that leaves some 1,500 entirely unknown dinosaur species to discover. Ladies and gentlemen, grab your rock hammers.
(Image: Wikipedia/David Monniaux) ***Kind of incredibly, Benton suggests that whatever naming mistakes might be happening nowadays are partly the fault of - you guessed it - the media. From the paper:
The aims of this study are to explore the recent burst of dinosaur work and to resolve whether the new phase is illusory or not. It could be that palaeontologists are producing poor-quality work, perhaps fuelled in part by excessive interest from museums and the media worldwide
****We also recommend obtaining a Ph.D. in paleontology.