Matgrounds are strong surface layers of seabed-hardening bacterial fauna preserved in the

Proterozoic The Proterozoic ( ) is the third of the four geologic eons of Earth's history, spanning the time interval from 2500 to 538.8 Mya, and is the longest eon of Earth's geologic time scale. It is preceded by the Archean and followed by the Phanerozo ...

and lower

Cambrian The Cambrian ( ) is the first geological period of the Paleozoic Era, and the Phanerozoic Eon. The Cambrian lasted 51.95 million years from the end of the preceding Ediacaran period 538.8 Ma (million years ago) to the beginning of the Ordov ...

. Wrinkled matgrounds are informally named "elephant skin" because of its wrinkled surface in the fossil record. Matgrounds supported themselves until early burrowing worms were ubiquitous enough to unharden them. Burrowing animals broke down the hardy mats to further penetrate the underlying sediment for protection and feeding. Once matgrounds disappeared, exceptional preservation of lagerstätten such as the

Burgess Shale The Burgess Shale is a fossil-bearing deposit exposed in the Canadian Rockies of British Columbia, Canada. It is famous for the exceptional preservation of the soft parts of its fossils. At old (middle Cambrian), it is one of the earliest fos ...

Ediacara Hills Ediacara Hills ( ), also known as Ediacaran Hills, are a range of low hills in the northern part of the Flinders Ranges of South Australia, around north of the state capital of Adelaide city centre, Adelaide. They are within the Nilpena Ediaca ...

also did so too.

Trace fossils A trace fossil, also called an ichnofossil (; ), is a fossil record of biological activity by lifeforms, but not the preserved remains of the organism itself. Trace fossils contrast with body fossils, which are the fossilized remains of part ...

such as '' Treptichnus'' are evidence for soft-bodied burrowers more anatomically complex than the Ediacaran biota that also caused the matgrounds disappearance.

References

Proterozoic life Microbiology Evolutionary biology Precambrian {{paleo-stub

See also

References