Petrolacosaurs

The Father of all reptiles

In the Carboniferous period, 354 to 290 million years ago, a tropical climate prevailed on Earth from the North Pole to the South Pole.

The lowland areas were covered with gigantic tropical forests where tree-sized ferns, horsetails and lycopods, up to 50 metres high, formed a thick vegetation. It is assumed that due to the extensive tropical forests, the oxygen content in the Earth's atmosphere was 30 percent higher in the Carboniferous than it is today.

Among other things, this meant that not only plants could reach gigantic proportions. Giant insects dominated the earth. And the first reptiles appeared on the scene as well, among them Petrolacosaurus.

Petrolacosaurus was already much more agile than most amphibians of its time. And although it was downright tiny compared to later reptilian giants like the dinosaurs, there is an amazing parallel:

When well-preserved fossils of Petrolacosaurs were found in the 1970s, palaeontologists were able to prove, based on the easily recognisable skeletons, that the small reptiles were almost certainly the ancestors of the dinosaurs and crocodiles.