Through the late Triassic period, once the terrestrial world was an individual sprawling land mass called Pangaea, a dog-size plant-eating dinosaur perished near a river in the southern section of the continent. Once the river flooded, its body was buried by sediment, with some bones still articulated as in life.
About 230 million years later, paleontologist Chris Griffin, a doctoral student at the Virginia Polytechnic Institute and State University, spotted a thigh bone protruding of a hill in the Cabora Bassa River Basin in what’s now Zimbabwe. Ive got a dinosaur! he called to his team.
The moment I dug that out, I knew that I was holding Africas oldest dinosaur, says Griffin, now a postdoc at Yale University. I had to sit back and breathe for one minute, because I thought, There may be much more [bones] within.
In the weeks that followed, Griffin and paleontologists Darlington Munyikwa and Michel Zondo of the Natural History Museum of Zimbabwe in Bulawayo unearthed a nearly complete skeleton. It proved to become a new species of early dinosaur: Mbiresaurus raathi, that they describe today in Nature.
Though small by dinosaur standards at 1.8 meters long, the find has outsize implications for the first spread of dinosaurs, says Stephen Brusatte, a vertebrate paleontologist at the University of Edinburgh who was simply not mixed up in study. Weve known close to nothing concerning the earliest dinosaurs in Africa, Brusatte says. It really is probably the most important recent dinosaur discoveries all over the world.
As yet, the initial known dinosaurs, also dating to about 230 million years back, were within Argentina and Brazil, with several partial specimens from India. Once the continents were gathered together to create Pangaea, the websites all lay at about 50 south, explains Diego Pol, a paleontologist at the Egidio Feruglio Paleontology Museum in Argentina who was simply not portion of the team. Earth was warmer at that time, lacking icecaps, and climate models claim that latitude on Pangaea had a wet, temperate climate with hot summers and cool, rainy winters. Researchers have suspected the initial dinosaurs needed this kind of climate, and that limited their spread over the supercontinent. But to verify that idea, they needed dinosaur fossils from other areas of exactly the same climate belt.
Griffins team began its hunt with a geological map, tracing a Pangaean-era latitude type of 50. They zeroed in on a shallow drainage in northern Zimbabwe where Munyikwa and Zondo knew other fossils have been found. If dinosaurs are third , climate, then we have to have the ability to find a few of the oldest dinosaurs the following in southern Africa, Griffin says they reasoned. And we did.
The M. raathi find, that was almost complete save for portions of the skull and forelimbs, was just very amazing and exciting, Munyikwa says. No larger than a collie, M. raathi is known as after Mbire, because the region was called through the 16th century Shona Empire, and a pioneering researcher who found fossils nearby. The dinosaur had an extended tail, a smallish head, and small, triangular teeth, suggesting it favored plants.
The team also found fragments of bones from the large carnivorous dinosaur called a herrerasaurid, the initial discovered in Africa. Also it unearthed a range of other animal fossils, too: cynodonts, which are mammal relatives; armored crocodilian relatives called aetosaurs; and archaic reptiles called rhynchosaurs. Paleontologists have discovered similar creatures across the same climate band in SOUTH USA and India.
Taken together, the fossils will be the strongest evidence yet that the initial dinosaurs and their relatives were constrained to a temperate climate belt bordered by arid ones, Pol says. The assemblage was nearly the same as that of SOUTH USA, he says. Dinosaurs were limited to their semihumid oasis for some million years, before arid regions to the north and south started to become wetter.
The rare find offers a welcome boost to Zimbabwes science that Munyikwa hopes can help attract more research funding. This new species [shows] we’ve essential deposits, he says. The fossils are actually on display at the Natural History Museum of Zimbabwe and so are a spot of pride for the city and nation, he says.
The analysis notes that other specimens likely await discovery over the same Pangaean climate belt, supplying a road map of sorts for other paleontologists on the search for early dinosaurs, says Kristi Curry Rogers, a vertebrate paleontologist at Macalester College. Now its time for all your rest folks employed in dinosaur paleobiology to access work and find out even more early dinosaurs.