Cyrtonellida is a group of "
monoplacophora
Monoplacophora , meaning "bearing one plate", is a polyphyletic superclass of molluscs with a cap-like shell inhabiting deep sea environments . Extant representatives were not recognized as such until 1952; previously they were known only from ...
", representing either a sister
taxon
In biology, a taxon ( back-formation from '' taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular n ...
to, or a
polyphyletic assemblage
A polyphyletic group is an assemblage of organisms or other evolving elements that is of mixed evolutionary origin. The term is often applied to groups that share similar features known as homoplasies, which are explained as a result of converg ...
including, the
Trybliida.
Subtaxa
*
Carcassonnellidae
*
Cyrtolitidae
Cyrtolitidae is an extinct family of monoplacophorans in the order Cyrtonellida.
Genera
* '' Cloudia''
* '' Cyclocyrtonella''
* '' Cyrtolites''
* '' Cyrtonellopsis''
* '' Kolihadiscus''
* '' Neocyrtolites''
* '' Paracyrtolites''
* '' Quasisin ...
*
Cyrtonelloidea
*
Pollicinidae
; Genera
* ''
Aremellia''
* ''
Hamusella''
* ''
Tetamocornu''
* ''
Yangtzeconus''
* ''
Yochelsonia''
References
External links
*
Prehistoric monoplacophorans
Mollusc orders
{{Paleo-mollusc-stub