''Yarnemia ascidiformis'' is a fossil tentatively classified as a

tunicate A tunicate is a marine invertebrate animal, a member of the subphylum Tunicata (). It is part of the Chordata, a phylum which includes all animals with dorsal nerve cords and notochords (including vertebrates). The subphylum was at one time ca ...

. While ''Y. ascidiformis'' looks similar to tunicates, the oldest unequivocal tunicate, ''

Shankouclava ''Shankouclava'' is an extinct genus of tunicate. It represents the oldest, unequivocal genus of tunicates, from 520 million years ago. It has been found in the Lower Cambrian Maotianshan Shale at Shankou village, Anning, near Kunming (South Chi ...

'' dates to the

Cambrian The Cambrian Period ( ; sometimes symbolized C with bar, Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million ...

period, while ''Y. ascidiformis'' is

Ediacaran The Ediacaran Period ( ) is a geological period that spans 96 million years from the end of the Cryogenian Period 635 million years ago (Mya), to the beginning of the Cambrian Period 538.8 Mya. It marks the end of the Proterozoic Eon, and th ...

in age.University of California Museum of Paleontology Berkeley
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Etymology

The generic name ''Yarnemia'' comes from the village of Yarnema near which the first specimens were found. The specific epithet, ''ascidiformis'', refers to the likeness to

ascidians Ascidiacea, commonly known as the ascidians, tunicates (in part), and sea squirts (in part), is a polyphyletic class in the subphylum Tunicata of sac-like marine invertebrate filter feeders. Ascidians are characterized by a tough outer "tunic" ...

References

Ediacaran life Tunicate genera Prehistoric chordate genera Fossil taxa described in 1984 {{paleo-deuterostome-stub

Etymology

See also

References