Tsintaosaurus The Prehistoric Unicorn

The Tsintaosaurus has always been a strange hadrosaur. This is partly what has made the shovel-billed herbivore a favourite in dinosaur books and model collections. Instead of the domes or tubes found in other crested hadrosaurs, such as the famous Corythosaurus and Parasaurolophus, the strange Tsintaosaurus seemed to have nothing more than a point with a small fork at the end.

It was a unicorn with the head of a duck. And as some artists thought this cranial decoration was a bit dull, they often added round, inflatable bags at the base of the point. But that’s bullshit.

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The mystery of what Tsintaosaurus really looked like goes back to the Upper Cretaceous fossils of China that paleontologists have discovered. An old-fashioned restoration of the Tsintaosaurus by ДиБгд, with inflatable bags at the base of the spike. Image from Wikimedia Commons.

The mystery of what tsintaosaurus actually looked like dates back to the Upper Cretaceous fossils of China that paleontologist Yang Zhongjian (also known as C.C. Young) described in 1958. In his reconstruction, Yang imagined a tubular spike made of nasal bones protruding from the dinosaur’s skull. But this ornament was so different from that of other crested hadrosaurs that other researchers wondered if the spike was a real feature. Paleontologist Philippe Taquet, for his part, suggested that the peak of Tsintaosaurus might simply be a nasal bone that was torn off by deformation after the hadrosaur died.

But the skull described by Yang was not the only one. Another partial skull, previously studied by Eric Buffetaut and Haiyan Tong, had cranial bones in similar positions to support a crest, and the new study also attributes a pair of forgotten cranial bones to the Tsintaosaurus. The spiky nasal bone was a real feature and close to its actual location. And with this material in hand, Prieto-Márquez and Wagner argue that this hadrosaur had a hollow, bulging crest that more closely resembled those of the dinosaur’s later relatives.

A new reconstruction of the skull of the Tsintaosaurus.ILLUSTRATION BY PRIETO-MÁRQUEZ AND WAGNER, 2013.

Rather than pointing forward, as is the case in many artistic representations, Prieto-Márquez and Wagner hypothesized that the spike-shaped nasal bone was connected to the prefrontal bone above the orbit and inclined backwards, thus forming part of the rear edge of the crest. The main body of the crest itself, which is still missing, would have consisted of premaxillary bones that connected the front of the snout to the rear nasal tip. The Skull Of The Tsintaosaurus was probably more dino than unicorn.

The crest of the tsintaosaurus was not just for show, however. Like other crested hadrosaurs, which belong to a group called lambeosaurines, the Tsintaosaurus must have had nasal passages that passed through these enlarged premaxillary bones. This circuit would have allowed the tsintaosaurus to emit unique low-frequency calls, similar to those reconstructed on the basis of the crests and inner ears of the better known hadrosaurs. Dinosaurs like Tsintaosaurus were probably among the most vocal of all non-avian forms.

For the moment, however, the route that the dinosaur’s nasal passage would have taken is speculative. The bones involved have not been discovered and, despite its name, the nasal bone itself had little to do with the internal plumbing of the skull of the tsintaosaurus. Future discoveries will fill in what is missing. The test of the hypothesis lies in the undiscovered bones. This will give artists some leeway to imagine what the tsintaosaurus looked like, but fortunately for the dinosaur’s legacy, the hadrosaur will no longer have a suggestive tip.

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