Researchers have discovered a new prehistoric animal species from Tanzania dating back to nearly 240 million years, during the Triassic period. The new species – “dinodontosaurus isiyavamanda” – could help researchers reshape the timelines of early dinosaur evolution by refining the age of one of the world’s “most significant” fossil sites, a press release by the University of Bristol said. According to the study published Tuesday in the Journal of Vertebrate Palaeontology, some of the potentially earliest known dinosaur fossils found in Tanzania may have been younger than previously known. The discovery During a British expedition in 1963 to what is now called Tanzania, an “extensive” collection of “synapsid” fossils – tetrapod vertebrates of the mammal lineage that existed before dinosaurs – was discovered. The fossils found during this expedition were brought to the Natural History Museum in London, U.K. However, they were only “partly studied,” the news release stated. The identity of some of the fossils remained a mystery, along with the knowledge about the ecosystems they came from. Researchers examined one of the “undescribed” skeletons from this batch, belonging to a herbivorous group of synapsids called “dicynodonts,” and a more recently discovered fragmented skull. According to the news release, they discovered that the fossils in question belonged to the genus – a taxonomic rank above species – called dinodontosaurus. This was a surprise for the team, since dinodontosaurus was known to be exclusively from South America. Further testing and anatomic study confirmed it was a previously unknown species that was later named dinodontosaurus isiyavamanda, a reference to the land of the Wamanda people from the region of Tanzania, where the fossils were found. “The discovery has important implications beyond the identification of a new species,” the press release said. ‘Refining the timeline of dinosaur origins’ According to the study, the rocks in Tanzania where the dinodontosaurus isiyavamanda fossils were found are the same geological deposits where fossils known to represent the earliest dinosaurs were discovered. Earlier, these rocks were thought to share some “fossil genera” – taxonomic groups of extinct organisms – with rocks found in South America, which were classified as Middle Triassic, meaning between 237 million to 247 million years old. “As dinodontosaurus is now known to exist in both Tanzania and South America, it provides a new link between rock sequences in both countries and indicates that they are of equivalent age,” the release said. “New radiometric dates from South America suggest that these early dinosaur-bearing rock sequences are up to 10 million years younger than that of South Africa.” The findings have led to questions about when and where dinosaurs first evolved, since the evidence showed that the Triassic rocks found in Tanzania may not hold the potentially oldest-known dinosaur fossils. “The finding links the Tanzanian and South American fossil-bearing rocks, showing they are of equivalent age,” Hady George, a PhD student in the School of Earth Sciences at the University of Bristol and lead author of the study, said in the news release. “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,” he said. “Forthcoming research projects will examine the remaining fossil material and explore the biomechanics and ecology of Triassic dicynodonts.” According to the news release, the new discovery has shed light on further research required since a large amount of the Tanzanian dinodontosaurus material “remains to be examined.”
