|Outdated restoration of a Protoceratops andrewsi nesting|
ground. Painting by Charles R. Knight, 1922.
We often look back with hindsight and, somewhat smugly, judge outdated hypotheses as inferior to those of today. We do this because, presumably, our modern notions about how prehistoric animals looked, moved, and behaved are closer to reality. However, 'The Truth' is a tricky concept when it comes to science, and its easy to forget that more than a quest for 'Truth', science is actually a long process of ever-refining hypotheses.
|Inaccurate(?) reconstruction of Spinosaurus aegyptiacus as a partially quadrupedal allosauroid-like animal. Painting by Giovanni Caselli, from the book The Evolution of Ecology of the Dinosaurs by L.B. Halstead. Originally posted by Marc Vincent here.|
So is it really fair to laugh at those silly old scientists in the 1930s who thought Oviraptor was an egg thief that preyed on Protoceratops nests just because it was found near eggs? Just like us and our Spinosaurus, that was actually a reasonable explanation at the time. The eggs were attributed to Protoceratops primarily because there were lots of both. Protoceratops was the most common dinosaur found in the area, so it made sense to attribute the numerous eggs to that genus. The fact that the Oviraptor, known only from the one skeleton, was found associated with one nest seemed likely to be a fluke, which could reasonably be written off as a chance association due to other factors like predation. The scientists who labelled Oviraptor an egg thief were drawing the most logical conclusion they could given the current evidence. The fact that later evidence proved this conclusion wrong doesn't make them foolish--that's how all science is supposed to work. Assuming right off the bat that the Oviraptor was the parent brooding its own eggs would have been an extraordinary claim lacking extraordinary supporting evidence (e.g. embryos or a clearly preserved brooding posture) and therefore could not be considered justifiable until the discoveries of really extraordinary specimens in the 1990s.
We can take this view all the way back to the earliest reconstructions of dinosaurs. It's well known that those silly Victorians reconstructed theropods and ornithopods as plodding, four-legged, lizard-like beasts. It's easy to overlook the fact that this was actually an entirely reasonable interpretation given the evidence at the time. Bipedal reptiles were unheard of, and anatomical evidence in the early days of dinosaur paleontology led many researchers to conclude that these animals were indeed lizard-like or crocodile-like, if not actual giant squamates. Anyone who suggested to William Buckland that the bones of Megalosaurus may in fact have come from a bipedal animal would rightly have been ignored. They would have been right, of course, but it would have been a position based on a lucky guess rather than good science. Given the scrappy material Victorian scientists had to work with and almost complete lack of closely related forms outside lizards and crocodiles, concluding that Megalosaurus was a basically lizard- or croc-like quadruped with some odd mammal- or bird-like features was the most reasonable thing to do.
|Citipati osmolskae embryo in egg. |
Photo by Jordi Paya, licensed.
So, the next time somebody claims Spinosaurus was a lumbering quadruped mistakenly given the head of a crocodile, you should feel justified in ridiculing the idea as pure fantasy, but don't be too disappointed if it later turns out to have been an incredibly lucky guess.