''Trepassia'' is a 579 million-year-old fossil of

Ediacaran The Ediacaran ( ) is a geological period of the Neoproterozoic geologic era, Era that spans 96 million years from the end of the Cryogenian Period at 635 Million years ago, Mya to the beginning of the Cambrian Period at 538.8 Mya. It is the last ...

rangeomorph The rangeomorphs are a group of Ediacaran Ediacaran biota, fossils. Ediacarans are the oldest large fossil organisms on earth, and many are not self-evidently related to anything else that has ever lived. However, some Ediacarans clearly resemble ...

. It was first discovered by Guy M. Narbonne, a professor at Queen's University in Ontario, Canada and colleagues in 2009. Three years later, Martin D. Brasier added additional description to ''Trepassia.'' The generic name is taken from the French word, trépassés, which translates to "those that have departed forever" (or "corpses") and honors the Trepassey community in Newfoundland. It was originally described as ''

Charnia ''Charnia'' is an extinct genus of frond-like lifeforms belonging to the Ediacaran biota with segmented, leaf-like ridges branching alternately to the right and left from a zig-zag medial suture (thus exhibiting glide reflection, or opposite is ...

wardi''; it was referred under this synonym in a 2016 paper.

Morphology

''Trepassia'' is one of the oldest known rangeomorphs and spanned over one meter in length. Longest specimens of ''T. wardae'' reached .M. LAFLAMME, G. M. NARBONNE, C. GREENTREE & M. M. ANDERSON. 2016. Morphology and taphonomy of an Ediacaran frond: Charnia from the Avalon Peninsula of Newfoundland. Department of Geological Sciences and Geological Engineering, Queen’s University, Kingston, Ontario, Canada K7L 3N6. It is a long and slender rangeomorph, its structure consists of single-sided branches with both primary and secondary branches rising from a central stalk. The primary branches were capable of minor pivoting as shown in the bundles of secondary branches. The adult specimens of ''Trepassia'' had substantial thickness, shown by the cylindrical cross-section of the frond. The suspension-feed strategy of ''Trepassia wardae'' was that it used its long, slender petalodium for continuous feeding at all heights above the sea floor. ''Trepassia'' is believed to have reproduced asexually. Taller organisms were surrounded by large clusters of offspring. It grew by addition of new branches at the tip of the frond. There may be a link between its mode of reproduction and its large body size.

Distribution

''Trepassia'' is found in Spaniard's Bay on the

Avalon Peninsula The Avalon Peninsula () is a large peninsula that makes up the southeast portion of the island of Newfoundland in Canada. It is in size. The peninsula is home to 270,348 people, about 52% of the province's population, according to the 2016 Ca ...

of Newfoundland and in Mistaken Point Ecological Reserve in Newfoundland, Canada. ''Trepassia'' has only been found in

Newfoundland Newfoundland and Labrador is the easternmost province of Canada, in the country's Atlantic region. The province comprises the island of Newfoundland and the continental region of Labrador, having a total size of . As of 2025 the population ...

References

{{Taxonbar, from=Q51077157 Fossils Rangeomorpha