WASHINGTON (Reuters) – A relatively complete skeleton of a long-necked, long-tailed herbivore dug out of a rocky cliff above a Tanzanian river provides insight into the early development of a group of dinosaurs that later became the largest group on earth. Land animals ever.
The Cretaceous dinosaur Mnyamawamtuka in its vicinity is shown in this image, which was published on February 13, 2019 in Athens, Ohio. Mark Witton / Handout on REUTERS
Scientists announced on Wednesday the discovery of dinosaur fossils called Mnyamawamtuka moyowamkia, which had a length of about 8 meters (8 feet), had a weight of about one ton, lived 110 to 100 million years ago and an early and comparatively small member of the group called titanosaurs.
Titanosaurs, which ran on four columnar legs, appeared for the first time in the Cretaceous, perhaps 125 million years ago. At the time when an asteroid impact caused mass extinction that had doomed dinosaurs to failure 66 million years ago, titanosaurs had reached astonishing proportions. For example, the Patagotitan in Argentina was about 37 meters long and weighed 70 tons.
"Mnyamawamtuka is important because it is a relatively complete animal from the early part of titanosaur diversification. Therefore, it provides a critical view of the group before diversification takes place around the world, "said Ohio University Professor of Anatomy, Patrick O & Connor.
Mnyamawamtuka means "animal of Mtuka" because it was dug up near the riverbed of Mtuka in southwestern Tanzania.
"This excavation was rather complicated when it was discovered that the fossils were being eroded about 6 meters above the dry river bed by a vertical cliff surface," said O'Neo Connor.
"At first we worked only to stabilize the falling rocks and fossils, later climbing ropes and experienced excavator teams were used. It's a fantastic backdrop with monkeys, a variety of hornbills and other birds, any kind of insect under the sun, complete with a very cool dinosaur skeleton, "added O & Connor.
Some of the approximately 60 identified titanosaur species are known only from waste. Scientists have 45 percent of the Mnyamawamtuka skeleton – pretty good, as dinosaur fossils are used – including numerous vertebrae, bones of the fore and hind leg musculature, ribs and teeth, but not the skull.
A characteristic feature was the light heart shape of Mnyamawamtuka's caudal vertebra, which "perhaps played a role in stiffening the tail from side to side," said O'Neo Connor.
"It had not fully grown, which is evidenced by unfused parts of the skeleton. Therefore, we are currently not sure how big the adult size should be, "said O'Neo Connor.
Mnyamawamtuka lived in a warm, semi-arid environment in today's southern central Africa.
The research supported by the US National Science Foundation was published in the journal PLOS ONE.
A related video: youtu.be/fMESVALpmwY
Will Dunham coverage; Cut by Sandra Maler