Dinosaurs’ origin story just got a rewrite. A newly described 240-million-year-old species from Tanzania suggests that some of the oldest presumed dinosaur fossils in Africa are millions of years younger than believed – and that the first dinosaurs may have appeared later, or elsewhere, than paleontologists assumed.
The species, named Dinodontosaurus isiyavamanda after the land of the Wamanda people of southern Tanzania, is not a dinosaur at all. It belongs to the dicynodonts, tusked and beaked herbivores on the mammal lineage that flourished long before dinosaurs rose to dominance. An international team led by University of Bristol researcher Hady George described it from a skeleton collected by a 1963 British expedition – then stored, partly unstudied, at the Natural History Museum in London for more than 60 years.
Dinodontosaurus was previously known only from South America. Finding it in Tanzania’s Manda Beds links the fossil-bearing rocks of the two continents and shows they are of equivalent age. Combined with new radiometric dates from South America, that means the Tanzanian rocks – which produced fossils once treated as the oldest possible dinosaurs – are up to 10 million years younger than South African deposits long used as the age benchmark.
“Our discovery marks the first confirmed record of the genus Dinodontosaurus outside South America,” George said. “This helps confirm that the oldest dinosaur candidates from Tanzania are probably no older than those from South America, refining the timeline of dinosaur origins.” The study appears in the Journal of Vertebrate Paleontology.
Co-author Nigel Larkin first suspected the skeleton was a new species in a 1994 student thesis and waited nearly 30 years to see it published. The case shows how revisiting old museum collections can change our understanding of the past as much as new fieldwork – a theme echoing other recent paleontological surprises, from the feather preserved in 66-million-year-old dinosaur droppings to the true identity of North America’s so-called American cheetah.
Sources
Journal of Vertebrate Paleontology (study)
Featured image: Dmitry Bogdanov / Wikimedia Commons, CC BY 3.0.