205 million years ago, gigantic pterosaurs roamed the prehistoric seas. The ichthyosaurs were up to 26 meters long and about as big as a blue whale, reports an international research team after the investigation of a fossil mandible bone from the UK in the journal “Plos One”.
Their research also shows that this and similar bones found in the UK were not dinosaurs. This has long been suspected because of the size of the bones.
The researchers led by Dean Lomax from the University of Manchester (Great Britain) had already found the remnants of the lower jawbone in Lilstock, UK in 2016. The almost one meter long bone is broken into five parts and not complete. By comparing them with bones of other ichthyosaurs, the researchers drew conclusions about the body size of primeval animals.
Ichthyosaurs lived about 200 million to 90 million years ago. They were fully adapted to life in the water and lived exclusively in the sea. In total, about 80 species of fish dinosaurs have been described so far. Fish dinosaurs had a similar body shape to today’s dolphins and many small pointed teeth in the beak-like snout. They descend from lizard-like land animals and had to show up for breath.
The ichthyosaurs disappeared about 30 million years before the great mass extinction at the end of the Cretaceous, in which, among other things, the dinosaurs died out and the heyday of mammals began. The extinction of the fish dinosaurs about 93 million years ago is probably related to climate changes during this time. The diversity of the different types of ichthyosaurs gradually declined, as well as the evolutionary development of the group, the researchers reported in March 2016.