Trepassia is a distinct Ediacaran frond fossil with complex branches that highlight a repeating, modular pattern allowing it to grow to great lengths, often well over a meter long! This modular branching pattern is typical of Ediacaran fossils from Mistaken Point in Newfoundland, Canada; however it is unknown from any Cambrian or younger assemblages, implying that Trepassia represents an extinct lineage (much like the trilobites) that lack any modern representatives. However, in the Ediacaran Period some 580 million years ago, Trepassia was a dominant fixture in these ancient ecosystems and likely survived by absorbing dissolved organic nutrients directly from the water column.
Trepassia is particularly important because it represents one of the oldest examples of large (greater than a centimeter two), morphologically complex organisms in the fossil record. The name is derived from the French word “trespasses” implying those who have departed forever.