Ediacaran biota

The Ediacaran biota is an assemblage of mostly soft-bodied organisms known from fossils dating to the Ediacaran Period, roughly 635–539 million years ago. Its distinctive forms include organisms with no clear counterparts among living animals.

Ediacaran Period: The geological period from about 635 to 539 million years ago, preceding the Cambrian Period. The biota is defined by fossils from this interval.
Ediacara Member: A fossil-rich geological unit in South Australia's Rawnsley Quartzite, named for the Ediacara Hills. Its exceptionally preserved fossils gave the biota its name.
Dickinsonia: An oval, segmented Ediacaran fossil with a distinctive quilted appearance. Its fossils are among the best-known examples of the biota's unusual body forms.
Ediacaran–Cambrian extinction event: The major decline of characteristic Ediacaran organisms near the transition to the Cambrian Period. It marks the disappearance of many familiar forms from the fossil record.
Reginald Sprigg: An Australian geologist who reported fossils from the Ediacara Hills in 1947. His discovery brought the distinctive Australian fossils to scientific attention.
Fossil: Preserved remains, traces, or other evidence of past life. Most knowledge of the biota comes from fossil impressions and traces.
Avalon assemblage: An Ediacaran fossil assemblage, about 575–565 million years old, known especially from Newfoundland. Its deep-water communities show an early, distinctive phase of Ediacaran life.
Rangeomorpha: A group of frond-like Ediacaran organisms built from repeated branching units. Their fractal-like construction exemplifies a body plan unlike those of most living animals.
Cambrian explosion: A geologically rapid diversification of animal life beginning around 539 million years ago. Its expanding animal diversity contrasts with the distinctive forms that largely vanished beforehand.
Precambrian: The span of geological time before the Cambrian Period, encompassing most of Earth's history. Ediacaran fossils demonstrate that complex organisms lived within this vast earlier interval.

Linked from 16 pages