In 1978, a complete dinosaur skull and partial skeleton were discovered on a farm in the Free State province of South Africa. Paleontologists believed that the remains belonged to a member of Massospondylus carinatus, a long-necked species that frequently appears in southern Africa’s Lower Jurassic geologic formations. The fossil was ultimately sent to the University of Witwatersrand, Johannesburg, where it has been stored for the past 30 years.
But from the start, it was clear that something wasn’t quite right with the specimen, which was catalogued as BP/1/4779. Its skull, for one, was boxier than that of Massospondylus, prompting some researchers to assume that it had been distorted during the fossilization process. As Ian Sample reports for the Guardian, BP/1/4779 was also smaller than adults of the Massospondylus species, which could reach a length of around 20 feet, leading to the theory that the fossil represented a juvenile.
Now, a re-analysis of the remains has brought experts to a different conclusion. The fossil, according to a study published in the journal Peer J, belongs not to Massospondylus carinatus but to an entirely new species—one that had been “hiding in plain sight,” study co-author Paul Barrett tells Josh Davis of London’s Natural History Museum.
In order to determine that the fossil was not a Massospondylus, the researchers had to compare it to known Massospondylus specimens of different ages. That would have been hard to do with many other dinosaurs, “because it is rare to have a complete age series of fossils from a single species,” Kimberley Chapelle, lead study author and doctoral researcher at the Natural History Museum, tells Davis.
“Luckily,” she adds, “the most common South African dinosaur Massospondylus has specimens ranging from embryo to adult.”
The researchers were therefore able to perform CT scans on a series of Massospondylus skulls, some of them tiny, some of them fully grown adults. And when they scanned the BP/1/4779 skull, they observed more than 20 features that set it apart from all other sauropodomorphs, the group to which both Massospondylus and the mystery fossil belong. The team thus concluded that BP/1/4779 is a previously undocumented species, which they have dubbed Ngwevu intloko, meaning “grey skull” in Xhosa, one of South Africa’s official languages.
Ngwevu intloko was a bipedal creature, with a long neck and broad head. It was a plant eater, though it likely also preyed on small animals when it got the chance. Sample reports that the dinosaur measured around 13 feet in length and may have weighed up to 660 pounds.
The new species’ skull did not align with growth patterns observed in the range of Massospondylus specimens, leading the researchers to reject the hypothesis that it was a juvenile Massospondylus. In fact, according to the study authors, Ngwevu intloko was around 10 years old when it died and had reached nearly adult size. The team also found that the differences between Ngwevu intloko and Massospondylus could not be chalked up to crushing or compression during the fossilization period; the Ngwevu intloko bones simply did not display the sorts of breaks that one would expect had its remains been seriously disrupted.
This new study is particularly intriguing because it adds further nuance to our understanding of life after the “Great Dying”—a mass extinction event that occurred 250 million years ago, wiping out some 90 percent of the planet’s species in a span of 20,000 years. It was in the wake of this natural disaster that dinosaurs emerged, among them Massospondylus. Researchers used to believe that Massospondylus was the only sauropodomorph thundering through southern Africa in its time, managing to thrive in a depleted landscape. But recent research has shown that there “were actually six or seven sauropodomorph dinosaurs in this area, as well as variety of dinosaurs from other, less common groups,” Barrett tells Davis.
The study’s identification of Ngwevu intloko thus bolsters the notion that Massospondylus lived in a more complex ecosystem that scientists previously thought. It also highlights the importance of using advanced technologies to take a fresh look at very old fossils. As Barrett points, according to Sample, “[M]useum collections, even those that are heavily studied, often have the potential to surprise us with finds of brand new species.”