Graptolite Fossils

Description

Graptolite Fossils

Fossil graptolites are thin, often shiny, markings on rock surfaces that look like pencil marks, and their name comes from the Greek for ‘writing in the rocks’. They are the remains of intricate colonies, some of which accommodated up to 5000 individual animals; these individuals lived in a skeleton of collagen, similar to the material from which our fingernails are made. We focus on the two main groups: dendroids and planktonic graptolites.

They lived between the Cambrian and Carboniferous periods, about 520 to 350 million years ago.

Graptolites are excellent geological time-keepers; they can be used to date the rocks in which they are found. They evolved quickly and assumed a wealth of easily recognisable shapes. Many of these evolutionary steps, which can be traced around much of the world, define periods of time. Some of these time-slices are only a few hundred thousand years long, which, to a geologist, amounts to pinpoint accuracy given that all this took place hundreds of millions of years ago!

Single Graptolite Fossil 30mm – 40mm