Reptiles have shown great evolutionary progress. They first appeared in the Late Carboniferous Period (320 million years ago). However, from the end of the Triassic Period they began to rapidly evolve and develop. Dinosaurs evolved to inhabit the land and pterosaurs spread their giant wings into the skies. Also, creatures such as fish-shaped ichthyosaurs, spindle-shaped plesiosaurs, and sea lizards swam in the seas. The great variety of reptiles that included dinosaurs thrived for 160 million years until the end of the Mesozoic Era 66 million years ago.