Ausia fenestrata Temporal range:Ediacaran
Fossil and M. Fedonkin reconstruction ofAusia as sponge-like organism
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Subphylum:	Tunicata
Class:	Ascidiacea
Genus:	†Ausia Hahn and Pflug, 1985
Species:	†A. fenestrata
Binomial name
†Ausia fenestrata Hahn and Pflug, 1985[1]

Ausia fenestrata is a curiousEdiacaran period (635 – 539 million years ago)^[2]fossil represented by only one specimen 5 cm long from theNama Group, aVendian toCambrian group of stratigraphic sequences deposited in the Nama foreland basin in central and southernNamibia.^[1] It has similarity toBurykhia from Ediacaran (Vendian)siliciclastic sediments exposed on the Syuzma River ofArkhangelsk Oblast, northwest Russia.^[3][4][5]This fossil is of the form of an elongate bag-like sandstone cast (Nama-type preservation) tapering to a cone on one end. The surface of the fossil is covered with oval depressions ("windows") regularly spaced over the surface in the manner of concentric/parallel rows. The taxonomic identity ofAusia is unresolved.

• G. Hahn and H. D. Pflug suggested thatAusia is apennatulacean coral from the family Veretillidae, but there are no signs of secondary polyps on the fossil, which are nonetheless represented in Hahn and Pflug's reconstruction.^[1] No veretillids are represented in the fossil record as far as is known.^[6]
• Some researchers have assumed that these depressions are pores and interpretedAusia as an ancestor ofarcheocyathans and other sponge-like organisms^[4] or truesponge.^[7] ButAdolf Seilacher has argued that the "windows" are merely dimples.^[7]
• Ausia may representascidians (sea squirts),^[8] an invertebrate group related to thechordates.^[5][9] Results of a new study of aBurykhia from Russia have shown a possible affinity of these organisms to the ascidians, which areurochordates. 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.^[5] 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.^[5]
• Jerzy Dzik has suggested thatAusia bears some similarity to thehalkieriids, and resembles the body plan that might be expected of halkieriid ancestors under thecoeloscleritophoran hypothesis.^[10][11]

• 
  Hahn and Pflug reconstruction ofAusia as apennatulacean
• 
  Reconstructed as a tunicate

• List of Ediacaran genera
• Yarnemia, another Ediacaran thought to be a tunicate.

• Ediacaran life
• Fossils of Namibia
• Fossil taxa described in 1985

• CS1 errors: missing periodical
• Articles with short description
• Short description matches Wikidata
• Articles with 'species' microformats
• Taxonbars desynced from Wikidata