Shimanskya

Shimanskya
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Cephalopoda
Subclass:	Coleoidea
Superorder:	Decapodiformes
Order:	Spirulida?
Family:	Shimanskyidae Doguzhaeva, Mapes & Mutvei, 1999
Genus:	Shimanskya Doguzhaeva, Mapes & Mutvei, 1999
Species
Shimanskya postremus (Miller, 1930)
Synonyms
Bactrites postremus Miller, 1930

Shimanskya is a late Carboniferous fossil tentatively interpreted as an early spirulid.^[1] However it lacks any clearly diagnostic characters and its affinity is best considered to lie in an unresolved stem group.^[2]

References

↑ Strugnell, J.; Jackson, J.; Drummond, A. J.; Cooper, A. (2006). "Divergence time estimates for major cephalopod groups: evidence from multiple genes". Cladistics 22: 89–96. doi:10.1111/j.1096-0031.2006.00086.x.
↑ Warnke, K; Plötner, J; Santana, JI; Rueda, MJ; Llinas, O (2003). "Reflections on the phylogenetic position of Spirula (Cephalopoda): preliminary evidence from the 18S ribosomal RNA gene" (PDF). Berliner Paläobiologische Abhandlungen 3: 253–260.

Notable fossil cephalopods (listed by first occurrence)

Cenozoic

The belemnite-cuttlefish-like Belosaepia

Evolutionary history of cephalopods

Mesozoic

Advanced nautiloids Nautilaceae True ammonites

Early coleoids Proteroctopus Styletoctopus Keuppia Palaeoctopus Paleocirroteuthis

Ceratitid ammonoids late Nautilida

Advanced belemnoids Diplobelids: Diplobelus Belemnites: Belemnites Belemnopsis Belemnotheutis

Palaeozoic

First appearance of long-lasting lineages Goniatite and ceratite ammonoids Probable coleoid ancestor Bactritida Earliest belemnoids: Aulacocerids: Aulacoceras Phragmoteuthids: Phragmoteuthis

Early forms the earliest cephalopod group Ellesmerocerida Orthocones: Endocerida, Orthocerida, Actinocerida Brevicones: Ascocerida, Oncocerida Earliest coiled cephalopods: Tarphycerida Spirulid?: Shimanskya

Octopus Pohlsepia

Cambrian

Earliest unambiguous cephalopods: Plectronocerida
- Plectronoceras
Monoplacophoran-like ancestral forms: Knightoconus
Possible, nude, "stem-group cephalopods": Nectocarididae

This article is issued from Wikipedia - version of the Saturday, October 17, 2015. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.