''Sphenothallus'' is a problematic extinct genus lately attributed to the conulariids. It was widespread in shallow marine environments during the

Paleozoic The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon. The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838 by combining the Greek words ''palaiós'' (, "old") and ' ...

Occurrence

''Sphenothallus'' is represented in the Cambrian period in the Kaili biota and the

Mount Stephen trilobite beds The Mount Stephen trilobite beds (UNSM locality 14s) are a series of fossil strata on Mount Stephen, British Columbia that contain exceptionally preserved fossil material. Part of the same stratigraphic unit as the Burgess Shale deposit, many non- ...

, where it co-occurs with the similar organisms '' Cambrorhythium'' and '' Byronia''. It is known in younger strata in Canada and the US, surviving at least until the Mississippian.

Ecology

''Sphenothallus'' lived in groups as an opportunist in environments from

hardground Carbonate hardgrounds are surfaces of synsedimentarily cemented carbonate layers that have been exposed on the seafloor (Wilson and Palmer, 1992). A hardground is essentially, then, a lithified seafloor. Ancient hardgrounds are found in limestone ...

Occurrence

Ecology

Notes

References

External links