The Ancestors of Virtually all Modern Animals

The Burgess Shale was discovered by palaeontologist Charles Doolittle Walcott, in 1909, in western Canada.

The remarkably well-preserved fossils found here, in black shales, are about 508 million years old.

It was not until 1962 that serious investigations began of the strange and diverse remains of creatures from the Cambrian Period (roughly 542 million to 505 million years ago). 

The fossils found in the Burgess Shale include the ancestors of most modern animals.

These animals lived during what we call “The Cambrian Explosion”.

Many of these organisms went extinct. But those that didn't diversified into many more species during the Cambrian period.

The basic body types of the major animal phyla (about three dozen) that exist today were established over a relatively short period of about 10 million years from these Cambrian faunas.

Burgess Shale fossils show exceptional soft-body preservation that are not usually preserved in normal conditions.

Trilobites are very common fossils in the Burgess Shale. These are hard-bodied bug-like creatures that lived on the seafloor for almost 300 million years until they went extinct before the era of dinosaurs.

Olenoides Trilobite Fossil, at the Burgess Shale, Canada, is about 350mm long and 530 million years old

Hallucigenia is a genus of Cambrian animals found in the Burgess Shale. The name reflects its unusual appearance and history. The Hallucigenia was later recognised as part of lobopodians, Paleozoic panarthropods from where velvet worms, water bears and arthropods arose.

Hallucigenia is a genus of Cambrian animal resembling worms, known from articulated fossils in Burgess Shale-type deposits in Canada

A combination of environmental factors probably contributed to this evolutionary burst.

Homeobox genes,  master genes controlling the formation of muscles, nerves, or glands, are similar in all species. The mutations that give rise to these master genes may only be advantageous in the earliest, simplest animals.

The Burgess Shale has contributed greatly to the understanding of the origins of animals on Earth.

At Walcott Quarry, Burgess Shale, Canada

Burgess Shale formation of British Columbia, Canada