I really don’t know what it is about dinosaurs with sails. Ever since I was a kid, they’ve been paleo stars. No book about dinosaurs seemed complete without a Spinosaurus, and the appeal of finbacked saurians was so great that even Dimetrodon – a distant protomammal cousin of ours – has often been erroneously thrown into the Mesozoic mix. Maybe it’s simply because they’re flashy. Those big sails are basically organic billboards, and, just as flowers evolved to look attractive, maybe there’s something similar is going on with those ludicrous neural spines. They stand out because they evolved to.

Spinosaurus, of course, is a major celebrity. Jurassic Park III, crummy as it was, saw to that. But there is another sail-backed dinosaur that I used to see in plenty in pop paleo that has subsequently fallen into the spinosaur’s shadow. I’m talking about Ouranosaurus.

This sail-bearing herbivore is still pretty new as dinosaurs go. Paleontologist Philippe Taquet described the dinosaur in 1976 from a bones found in the 125-112 million year old rock of Niger. Even now, the dinosaur is an oddity. While an early cousin of the duck-billed hadrosaurs, Ouranosaurus had a mishmash of features – including thumb spikes, a prominent and perhaps decorative bump on its skull, and, of course, the sail – that would make it stand out in any crowd.

Despite the dinosaur’s relative fame, though, its scientific backstory is a little bit tangled. Taquet based his description on two skeletons and a few additional bones. But as paleontologist Filippo Bertozzo and colleagues point out, there’s another skeleton that has stood in the Natural History Museum of Venice since 1975. Was this the second skeleton Taquet mentioned in his work? Or a third, previously-unreported dinosaur? Who is this Venice dinosaur, really?

This isn’t just paleo bookkeeping. When studying a dinosaur skeleton, it’s important to know where it came from and what it actually is. Pretty as mounted skeletons are, they often include casts or bones from multiple individuals in order to present museum visitors with a complete animal. So if a paleontologist is going to study a composite, they need to know which bones come from a single individual – representing one actual animal – and which were added from various sources if they’re going to do anything from analyze body size to evolutionary relationships.

Ouranosaurus
Quarry map of bones included in the Venice Ouranosaurus. Credit: Bertozzo et al 2017

In the case of the Venice Ouranosaurus, Bertozzo and colleagues found out that the specimen was uncovered in 1972 during a French-led expedition to Niger. This was one of many Ouranosaurus specimens discovered over several French, Italian, and collaborative expeditions since the 60s. But as confirmed by Taquet and an unpublished field map from the expedition, the Venice Ouranosaurus contains at least part of what paleontologists call a paratype – the second skeleton that was used to initially name the dinosaur. 

But there’s a catch. After going through the skeleton bone by bone, Bertozzo and coauthors didn’t find an exact match the quarry map they were provided. There’s some discrepancy between the records and the actual bones. It could be that only some of the bones on the map were used in the mount, with the rest going to another museum in Niger. Then again, it might be that the skeleton was supplemented with bones of another specimen. Or both could be true. The mount contains at least some bones from the paratype, but there could be others in the mix. Apparently no one kept notes as to what was what.

Paleo paperwork doesn’t seem very exciting. Having to do some of it myself, in fact, I can say the feeling is pretty much the opposite of the joy at finding a shiny fossil in the field. But when I’ve stalked up and down museum collection cabinets, sheaf of notes in my hand as I search for a lost bone, I’m often privately cursing the previous paleontologists who didn’t number specimens, record where they came from, or paid much attention at all to their notes.

Paleontology isn’t ripping fossils out of the ground and putting them on a shelf. It’s a science, and that requires the careful collection of maps, notes, and data. Otherwise how are we to know what’s what? A beautiful dinosaur mount is practically useless if you can’t be sure where it came from or where all the fossils in that reconstruction came from. The dedicated work of Bertozzo and colleagues has made sense of a mysterious Ouranosaurus, but, as much of an anatomical redescription, their paper is a reminder to take damn good notes.

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Reference:

Bertozzo, F., Dalla Vecchia, F., Fabbri, M. 2017. The Venice specimen of Ouranosaurus nigerensis (Dinosauria, Ornithopoda). PeerJ. doi: 10.7717/peerj.3404