There are plenty of underappreciated dinosaur families. I’ve never once heard someone get excited about the svelte little hypsilophodonts, for example, and snappy coelophysoids usually only get fame for their relevance to the evolution of later, larger, toothier carnivores. Sauropodomorphs have suffered a similar fate.
Encompassing the largest land animals of all time, sauropodomorphs are incredibly varied. You undoubtedly know some of the later forms in the pillar-legged, long-necked sauropod subdivision – Brachiosaurus, Diplodocus, Apatosaurus, and the rest. But usually when we talk about sauropodomorphs proper, we mean the earlier relatives of these giants. The mostly-herbivorous dinosaurs with strange, boxy skulls, long necks, huge hand claws, and – most of the time – a bipedal posture that made them look incredibly gawky.
Sauropodomorphs don’t present a straight-line progression from omnivorous, bipedal ancestors to four-on-the-floor, herbivorous descendants. That transition undoubtedly occurred, but focusing on that point alone would miss the grand variety of the sauropodomorph family. Some were the first large dinosaurs to evolve. Others stayed small. Many tottered around on two legs. Some evolved a four-legged posture, anticipating the true giants of the Jurassic. And even though their paleobiology is still somewhat hazy, sauropodomorphs were apparently varied enough that parts of the world like Late Triassic and Early Jurassic South Africa boasted multiple overlapping species. In fact, paleontologists have just named another.
Described by Kimberley Chapelle and colleagues, the new dinosaur was once known by another name. The skull and partial skeleton BP/1/4779 was labeled to be Massospondylus carinatus, a species of a well-known sauropodomorph named back in 1854. But according to the new analysis by Chapelle and coauthors, the fossil is a previously-unknown dinosaur. They’ve named the creature Ngwevu intloko. Pronounced “Ng-g’where-voo in-tloh-koh,” the name is a Xhosa translation of the fossil’s nickname “grey skull.”
Other sauropodomorphs have been found in equivalent layers of the Elliot Formation, which spans about five million years, but none seem closely related to Ngweyu. Nor does the dinosaur seem to be part of a straight-line evolutionary march from older ancestors in the area. Perhaps Ngweyu migrated from elsewhere, represents a split lineage that rapidly evolved from local ancestors, or its predecessors have yet to be found. Chapelle and colleagues also note that Ngweyu probably isn’t a juvenile of another, previously-known species. BP/1/4779 was an adult animal, about 10 years old when it died.
For forty years, BP/1/4779 was thought to be another example of a common dinosaur. Now it seems to be something new. This goes beyond adding another dinosaur to the ever-growing list. How Ngweyu evolved and the details of the dinosaur’s ecology may help us understand the early days of when dinosaurs truly started to rule terrestrial ecosystems. The dinosaur is another fossil piece that helps change the context of other finds around it, and is changed in turn. And at a purely simple level, Ngweyu is further proof that sauropodomorphs rock.