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

Sphenothallus
Temporal range: Upper Lower Cambrian–Mississippian[Note 1][1][2][3]
Sphenothallus holdfast from the Kope Formation (Upper Ordovician), Gunpowder Creek, Kentucky.
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Cnidaria
Class: Staurozoa
Order: Conulatae
Clade: Conulariida
Genus: Sphenothallus
Hall, 1847

Occurrence edit

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 edit

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 edit

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

References edit

  1. ^ a b 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. ^ a b Bodenbender, B. E.; Wilson, M. A.; Palmer, T. J. (1989). "Paleoecology of Sphenothallus on an Upper Ordovician hardground". Lethaia. 22 (2): 217–225. doi:10.1111/j.1502-3931.1989.tb01685.x.
  3. ^ a b c d 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 edit