Sphenothallus

{{Short description|Extinct genus of aquatic animals}}

{{Automatic taxobox

| taxon = Sphenothallus

| fossil_range = {{fossil range|Upper Lower Cambrian|Mississippian|ref=Earliest, upper Lower Cambrian (Van Iten et al 2002); latest, not referenced; at least to Mississippian}}

| image = SphenothallidHoldfastOrdovician.jpg

| image_caption = Sphenothallus holdfast from the Kope Formation (Upper Ordovician), Gunpowder Creek, Kentucky.

| authority = Hall, 1847

}}

Sphenothallus is a problematic extinct genus lately attributed to the conulariids. It was widespread in shallow marine environments during the Paleozoic.{{Cite journal| last1 = Bodenbender | first1 = B. E.| last2 = Wilson | first2 = M. A.| last3 = Palmer | first3 = T. J.| title = Paleoecology of Sphenothallus on an Upper Ordovician hardground| journal = Lethaia| volume = 22| pages = 217–225| year = 1989| issue = 2| doi = 10.1111/j.1502-3931.1989.tb01685.x}}{{cite journal

| doi = 10.4202/app.00049.2013

| title = Alleged cnidarian Sphenothallus in the Late Ordovician of Baltica, its mineral composition and microstructure

| year = 2015

| author = Vinn, O.

| author2 = Kirsimäe, K.

| journal = Acta Palaeontologica Polonica

| volume = 60

| pages = 1001–1008

| url = https://www.app.pan.pl/article/item/app000492013.html

| accessdate = 2014-06-11| doi-access = free

}}

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.{{Cite journal| last1 = Van Iten | first1 = H.| last2 = Zhu | first2 = M. Y.| last3 = Collins | first3 = D.| title = First Report of Sphenothallus Hall, 1847 in the Middle Cambrian| jstor = 1307202| journal = Journal of Paleontology| volume = 76| issue = 5| pages = 902–905| year = 2002| issn = 0022-3360| doi = 10.1666/0022-3360(2002)076<0902:FROSHI>2.0.CO;2| s2cid = 131018299}} It is known in younger strata in Canada and the US, surviving at least until the Mississippian.{{Cite journal| last1 = Neal | first1 = M. L.| last2 = Hannibal | first2 = J. T.| title = Paleoecologic and Taxonomic Implications Ofsphenothallusandsphenothallus-Like Specimens from Ohio and Areas Adjacent to Ohio| journal = Journal of Paleontology| volume = 74| issue = 3| pages = 369| year = 2000| issn = 0022-3360| doi = 10.1666/0022-3360(2000)074<0369:PATIOS>2.0.CO;2| s2cid = 130829810}}

Ecology

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

Notes

{{Reflist|group=Note}}

References

{{Reflist}}