Scientists from Swedish and Polish universities have discovered fossils of a massive 'mammal-like' reptile, which was about the size of an elephant and roamed Earth in the Triassic era (252-201 million years ago).
During the Triassic period, Earth had only one massive continent called Pangea, in place of the separate continents that exist today. The first dinosaurs, as well as the ancestors to mammals, crocodiles, lizards and frogs, evolved during this period.
The Triassic era also featured mammal-like reptiles called therapsids. One group of therapsids was the plant-eating dicynodonts, which were mostly toothless. These creatures became the dominant herbivores during the Middle and Late Triassic era, and even managed to survive the Permian mass extinction event (aka the Great Dying) around 250 million years ago, during which it is believed that approximately 90 per cent of the species on Earth were killed.
Dicynodonts likely died out before the emergence of dinosaurs as dominant tetrapods on land.
Now for the first time, scientists have discovered a new species of dicynodont that was a distant cousin to today's mammals. Called Lisowicia bojani, this creature was about 4.5 metres long, 2.6 metres high and weighed about 10 tonnes. It lived between 210 and 205 million years ago, in the Late Triassic era.
Dr. Grzegorz Niedzwiedzki, from Uppsala University, made the discovery of the new species, in collaboration with Dr. Tomasz Sulej from the Polish Academy of Sciences (Warsaw). They unearthed evidence of Lisowicia bojani from Lisowice village in Poland, a site rich in fossils.
The first fossils at Lisowice were discovered in 2005, and since then researchers have unearthed hundreds of bones and bone fragments in this area.
In 2008, Dr. Niedzwiedzki and Dr. Sulej discovered a 56-centimetre-long femur bone of a dicynodont at Lisowice. However, the latest skeleton is much larger and features an 80-centimeter-long femur bone. When unearthed, the skeleton was preserved in siltstone deposits.
Dicynodonts fossils have also been uncovered in other continents including Asia, Africa and North and South America, but they were smaller in size compared to the fossils discovered in Poland.
The latest finding shows that animals other than dinosaurs had managed to attain massive sizes during this stage of evolutionary history.
"The discovery of Lisowicia changes our ideas about the latest history of dicynodonts, mammal Triassic relatives," said Dr. Sulej.
He described it as "once in a lifetime discovery."
The findings of the study are published in journal Science.
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