An international team of paleontologists led by Virginia Tech has recently discovered, named, and described a new sauropodomorph – a long-necked dinosaur – which is, thus far, the oldest dinosaur skeleton ever found in Africa. The almost intact skeleton of Mbiresaurus raathi was found in northern Zimbabwe over the course of two digging operations, in 2017 and 2019. The creature is estimated to have been six feet long and to weigh between 20 and 65 pounds.
“The discovery of Mbiresaurus raathi fills in a critical geographic gap in the fossil record of the oldest dinosaurs and shows the power of hypothesis-driven fieldwork for testing predictions about the ancient past,” said study lead author Christopher Griffin, a former PhD student in Geology at Virginia Tech.
“These are Africa’s oldest-known definitive dinosaurs, roughly equivalent in age to the oldest dinosaurs found anywhere in the world. The oldest known dinosaurs — from roughly 230 million years ago, the Carnian Stage of the Late Triassic period — are extremely rare and have been recovered from only a few places worldwide, mainly northern Argentina, southern Brazil, and India.”
“Early dinosaurs like Mbiresaurus raathi show that the early evolution of dinosaurs is still being written with each new find and the rise of dinosaurs was far more complicated than previously predicted,” added study co-author Sterling Nesbitt, an associate professor of Geosciences at Virginia Tech.
The discovery of M. raathi – alongside a larger assortment of Carnian-aged fossils – sheds new light on dinosaur migration. Like all continents, Africa was once part of the supercontinent called Pangea, characterized by a climate divided into strong humid and arid latitudinal belts, with more temperate belts spanning higher attitudes and vast deserts extending across the lower tropics.
“Because dinosaurs initially dispersed under this climatic pattern, the early dispersal of dinosaurs should therefore have been controlled by latitude,” Dr. Griffin explained. “The oldest dinosaurs are known from roughly the same ancient latitudes along the southern temperate climate belt what was at the time, approximately 50 degrees south.” Zimbabwe – where M. raathi was discovered – falls along this climate belt, bridging a geographical gap between southern Brazil and India during the Late Triassic Age.
At the beginning, these dinosaurs were restricted by climatic belts to southern Pangea, and only later in history dispersed worldwide, during a period of intense worldwide humidity known as the Carnian Pluvial Event. After these migrations, barriers returned, mooring the dinosaurs in distinct provinces across Pangea for the remainder of the Triassic Period. Further research is needed to clarify the behavioral and migration patterns of M. raathi, as well as the role it played among the early dinosaurs.
The study is published in the journal Nature.
Image Credit: Virginia Tech