Anoigmaichnus is an ichnogenus of bioclaustrations (a type of trace fossil). Anoigmaichnus includes shafts perpendicular to their hosts' growth surfaces or tilted (up to 45°); conical to cylindrical; circular to oval cross-sections; lacking separate wall. Their apertures are elevated above their hosts' growth surfaces, forming short chimney-like structures. Anoigmaichnus is the world's earliest known macroscopic endobiotic symbiont and it may have been a parasite. It occurs in the Middle Ordovician bryozoans of Osmussaar Island, Estonia.[1]
Wisshak, Knaust and Bertling (2019) state that Anoigmaichnus odinsholmensis resembles Trypanites weisei, which occasionally shows elevated apertures in its type material, and therefore they regard Anoigmaichnus as a junior synonym of Trypanites.[2]
References
- ^ Vinn, O.; Wilson, M.A.; Mõtus, M.-A. & Toom, U. (2014). "The earliest bryozoan parasite: Middle Ordovician (Darriwilian) of Osmussaar Island, Estonia". Palaeogeography, Palaeoclimatology, Palaeoecology. 414: 129–132. Bibcode:2014PPP...414..129V. doi:10.1016/j.palaeo.2014.08.021. Retrieved 2014-01-09.
- ^ Wisshak, M.; Knaust, D.; Bertling, M. (2019). "Bioerosion ichnotaxa: review and annotated list". Facies. 65 (2): 24. doi:10.1007/s10347-019-0561-8.
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