Fossils of 540 million years ...

                                 Trilobites
Trilobites
They appeared about 540 million years ago. They lived in the Paleozoic seas and became extinct some 250 million years ago.

Its fossils are very abundant on all continents, especially north of Africa.
Its name means: Trilobulated. Some 4000 species have been described.

Photos of: Felix Collantes