Sphenothallus

Sphenothallus Temporal range: Upper Lower Cambrian–Mississippian [Note 1] [1] [2] [3] PreꞒ Ꞓ O S D C P T J K Pg N
Sphenothallus holdfast from the Kope Formation (Upper Ordovician), Gunpowder Creek, Kentucky.
Scientific classification
Kingdom:	Animalia
Phylum:	Cnidaria
Order:	† Conulatae
Clade:	† Conulariida
Genus:	† Sphenothallus Hall, 1847

Sphenothallus is a problematic extinct genus lately attributed to the conulariids. It was widespread in shallow marine environments during the Paleozoic. ^{[2] [4]}

Occurrence

Sphenothallus is represented in the Cambrian period in the Kaili biota and the Mount Stephen trilobite beds, where it co-occurs with the similar organisms Cambrorhythium and Byronia . ^[1] It is known in younger strata in Canada and the US, surviving at least until the Mississippian. ^[3]

Ecology

Sphenothallus lived in groups as an opportunist in environments from hardgrounds to soft mud, even if depleted in oxygen. ^[3] It probably dispersed via larvae. ^[3]

Notes

1. Earliest, upper Lower Cambrian (Van Iten et al 2002); latest, not referenced; at least to Mississippian

References

1. Van Iten, H.; Zhu, M. Y.; Collins, D. (2002). "First Report of Sphenothallus Hall, 1847 in the Middle Cambrian". Journal of Paleontology. 76 (5): 902–905. doi:10.1666/0022-3360(2002)076<0902:FROSHI>2.0.CO;2. ISSN   0022-3360. JSTOR   1307202. S2CID   131018299.
2. Bodenbender, B. E.; Wilson, M. A.; Palmer, T. J. (1989). "Paleoecology of Sphenothallus on an Upper Ordovician hardground". Lethaia. 22 (2): 217–225. Bibcode:1989Letha..22..217B. doi:10.1111/j.1502-3931.1989.tb01685.x.
3. Neal, M. L.; Hannibal, J. T. (2000). "Paleoecologic and Taxonomic Implications Ofsphenothallusandsphenothallus-Like Specimens from Ohio and Areas Adjacent to Ohio". Journal of Paleontology. 74 (3): 369. doi:10.1666/0022-3360(2000)074<0369:PATIOS>2.0.CO;2. ISSN   0022-3360. S2CID   130829810.
4. Vinn, O.; Kirsimäe, K. (2015). "Alleged cnidarian Sphenothallus in the Late Ordovician of Baltica, its mineral composition and microstructure". Acta Palaeontologica Polonica. 60: 1001–1008. doi: 10.4202/app.00049.2013 . Retrieved 2014-06-11.

External links

• "Sphenothallus sp.". Burgess Shale Fossil Gallery. Virtual Museum of Canada. 2011. Archived from the original on 2020-11-12.