Terreneuvian

The Terreneuvian or Early Cambrian is the oldest part of the Cambrian, a time in Earth's history when many new kinds of life appeared. It began about 538.8 million years ago, marked by the first appearance of a special trace fossil called Treptichnus pedum. This fossil shows where an ancient worm moved through the mud on the ocean floor.

The Terreneuvian ended about 521 million years ago, when the first trilobites showed up in the rocks. Trilobites were small sea creatures with hard shells, and they became very common later on.

The name Terreneuvian comes from Terre Neuve, the French name for the island of Newfoundland in Canada. Many important rocks from this time were found there, helping scientists understand this period better. The International Commission on Stratigraphy officially recognized this name in 2007.

GSSP

The Terreneuvian period begins at a special place called Fortune Head, located at the northern edge of the Burin Peninsula in Newfoundland, Canada. This area shows layers of rock that help scientists understand very old Earth history.

Important signs mark the start of this period, like special tracks made by ancient animals called Treptichnus pedum. Later, the first simple animals with shells appeared, followed eventually by the first trilobites, which signal the start of a new series called the Branchian Series.

Major events

The second phase of the Cambrian explosion happened during the Terreneuvian. Many different kinds of animal groups, like lophotrochozoan animals and some early metazoan animals with hard shells, appeared at this time. However, another group called deuterostomes was not present, except maybe one possible animal called Yanjiahella from an earlier time.