Ausia fenestrata is an Ediacaran fossil represented by only one specimen 5 cm long from the Nama Group, a Vendian to Cambrian group of stratigraphic sequences deposited in the Nama foreland basin in central and southern Namibia.
- Some researchers have assumed that these depressions are pores and interpreted Ausia as an ancestor of archeocyathans and other sponge-like organisms or true sponge. But Adolf Seilacher has argued that the "windows" are merely dimples. an invertebrate group related to the chordates. Results of a new study of a Burykhia from Russia have shown a possible affinity of these organisms to the ascidians, which are urochordates. The Russian species is more than 90 mm across, and the rows of oval depressions are separated by structures which were probably grooves in the internal wall surface of the living organism. The study's authors interpret these fossils as the internal sand casts of a vast bag-like cavity, possibly a pharynx or branchial basket. The animals represented by these two genera were thought to live in the shallow waters of an epicontinental sea, slightly more than 555-548 million years ago, and the authors feel this is probably the oldest evidence of the chordate lineage of metazoans.
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Ausia3.jpg|Hahn and Pflug reconstruction of Ausia as a pennatulacean
Ausia fenestra.jpg|Reconstructed as a tunicate
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See also
- List of Ediacaran genera
- Yarnemia, another Ediacaran thought to be a tunicate.