The Age of Dinosaurs officially began in the Triassic Period more than 225 million years ago, but dinosaurs were not the only things roaming the Earth. Most of the creatures in those times were small reptiles and shrews roaming about a semi-arid wasteland. Just before the Triassic Period began, the Permian extinction killed around 90 percent of all life in the sea and 70 percent of all life on land. Among those land-dwellers were the ancestors of humanity – mammal-like reptiles. The majority of those large transitional species were believed to be extinct until the discovery of Lisowicia bojani.
Named after the Polish village in which it was discovered, Lisowicia bojani was a toothless mammal-like reptile roughly the size of an elephant with a weight of 9,000 kg. It was the largest quadrupedal creature to rule over the Triassic landscape which was not officially considered a dinosaur.
Instead of teeth, this creature had a beak, giving it the appearance of being a hybrid of a modern-day hippo and a massive turtle. Up until the discovery of this creature, animals of its size and classification were not thought to have lived side-by-side with dinosaurs.
Animals such as Lisowicia bojani are part of a group believed to be the ancient ancestors of modern-day humans called dicynodonts, which translates to “two dog teeth.” Despite being named after the meat-getting parts of a modern-day carnivore, dicynodonts were herbivorous. They developed near the end of the Permian Period around 250 million years ago, and were thought to have become extinct before the Age of Dinosaurs.
This new discovery could change that method of thinking, however, if mammal-like reptiles such as Lisowicia bojani did in fact live into the age of dinosaurs, the picture of the Triassic Period would have a bit more biological diversity.
A large portion of scientists believe the Permian extinction was a direct result of the explosion of the Siberian Traps volcanic system located in modern-day Russia. The eruption of this cluster of super-volcanoes would have not only blocked sunlight with a blanket of sulfate aerosols, but also would have released toxic methane gas into the sea, which is why a larger portion of sea animals perished than land.
Mammal-like reptiles may have survived this extinction simply by not requiring as much water to live. They laid eggs or gave live birth, and would therefore not be as dramatically affected by the seas becoming toxic.