Paibian

The Paibian is an important time in Earth's history. It is a "stage" used to study rocks and fossils. It is the lowest stage of the Furongian Series, which is part of the Cambrian System. The Cambrian Period was when many of the first complex animals appeared in the oceans.

The Paibian follows a stage called the Guzhangian and comes before the Jiangshanian Stage. Scientists mark the start of the Paibian about 497 million years ago by looking for a special trilobite called Glyptagnostus reticulatus. This tiny sea creature helps them know when they are looking at rocks from this time.

By studying rock layers and fossils, scientists learn about life in the ancient seas during the Paibian. The end of the Paibian, around 494.2 million years ago, is marked by another trilobite, Agnostotes orientalis, which signals the start of the next stage, the Jiangshanian.

GSSP

The name Paibian comes from the village of Paibi in Hunan, China. The Global Boundary Stratotype Section and Point (GSSP) is found in the Paibi section in the Wuling Mountains, near Huayuan County. This spot marks the start of the Paibian stage. It is where the fossil Glyptagnostus reticulatus first appears.

Major events

At the turn of the Guzhangian and Paibian ages, many species disappeared. After this, life returned to normal levels.

The Steptoean positive carbon isotope excursion (SPICE) began around the Guzhangian-Paibian boundary. This changed the carbon cycle and affected trilobites.

Paleontology

The Paibian stage of the Cambrian period is known for fossils of small sea creatures. One group of these creatures is called agnostoids. Well-known types include Glyptagnostus, Homagnostus, Pseudagnostus, and Acmarhachis. These fossils help scientists learn about the ancient oceans and life from that time.