Page "Neoproterozoic" Paragraph 5

The idea of the Neoproterozoic Era came on the scene relatively recently — after about 1960.

Nineteenth century paleontologists set the start of multicelled life at the first appearance of hard-shelled animals called trilobites and archeocyathids.

This set the beginning of the Cambrian period.

In the early 20th century, paleontologists started finding fossils of multicellular animals that predated the Cambrian boundary.

A complex fauna was found in South West Africa in the 1920s but was misdated.

Another was found in South Australia in the 1940s but was not thoroughly examined until the late 1950s.

Other possible early fossils were found in Russia, England, Canada, and elsewhere ( see Ediacaran biota ).

Some were determined to be pseudofossils, but others were revealed to be members of rather complex biotas that are still poorly understood.

At least 25 regions worldwide yielded metazoan fossils prior to the classical Cambrian boundary.