''Tannuella'' is a genus of helcionellids known from
Lower Cambrian
The Cambrian Period ( ; sometimes symbolized Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million years ago (m ...
strata.
It has a high, septate shell similar to that of
hypseloconids such as ''
Knightoconus
''Knightoconus antarcticus'' is an extinct species of fossil monoplacophoran from the Cambrian Minaret Formation of Antarctica. It is thought to represent an ancestor to the cephalopods. It had a chambered conical shell, but lacked a siphuncl ...
'' . These genera were once considered ancestral cephalopods,
but are more broadly assigned to the
helconellids (or putatively the
tergomyans); i.e. "Cambrian monoplacophora".
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References
Helcionellidae
Prehistoric cephalopod genera
Cambrian molluscs
Paleozoic invertebrates of Oceania
Paleozoic animals of Asia
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