Class is in session.
During the Paleozoic era (570 – 245 million years ago), life evolved from simple bacteria and algae to invertebrates, vertebrates (primitive fish), the first air-breathing animal (a scorpion), more advanced sea creatures (i.e. sharks), spiders, dragonflies, amphibians, and early reptiles.

It was followed by the Mesozoic era (240 – 65 million years ago), also known as the Age of Reptiles. The Mesozoic is divided into three periods:
In the Triassic period (240 – 205 m.y.a.), small dinosaurs, icthyosaurs, and early mammals appeared, as did the pterosaur, an early relative.
In the Jurassic (205 – 138 m.y.a.), one finds the brontosaurus, tyrannosaurus, stegosaur, plesiosaur, early crocodiles, many insects and shellfish, and the first pterodactyls with wingspan about 4 ft (1.2 m).
In the Cretaceous (138 - 65 m.y.a.) in addition to the earlier dinosaurs came horned dinosaurs, the first snakes lizards and crabs, and early marsupials and placental mammals. Pterodactyls grew much larger, some fossils found in Texas measuring 50 ft (15.5 m) wingspans.

In the early part of the Cenozoic era, the large reptiles mysteriously vanished and the Age of Mammals began.

Word origin: early 19th century from Greek pteron (wing) and daktulos (finger).

Just, y'know, FYI.
- posted by Dactyl @ 11:19 AM