Decapodiformes

 ( Neocoleoidea ) 

Decapodiformes is a superorder of Cephalopoda comprising all cephalopod species with ten Cephalopod limb, specifically eight short arms and two long tentacles. It is hypothesized that the ancestral coleoid had five identical pairs of limbs, and that one branch of descendants evolved a modified arm pair IV to become the Decapodiformes, while another branch of descendants evolved and then eventually lost its arm pair II, becoming the Octopodiformes.

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Taxonomy The following orders are recognised in the superorder Decapodiformes:

• Bathyteuthida
• †Belemnitida
• †Diplobelida
• Idiosepida – pygmy squid
• Myopsida – coastal squid
• Oegopsida – neritic squid
• Sepiida – cuttlefish
• Sepiolida – bobtail and bottletail squid
• Spirulida – ram's horn squid

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Phylogeny Genetic testing consistently showed that the order Teuthida is invalid as its two constituent subgroups do not form a clade that did not exclude other decapodiform orders. Thus, Teuthida is presently considered an invalid order due to lack of monophyly.

Maximum Likelihood (ML) cladogram from Uribe & Zardoya 2017, based on complete Mitogenome (protein-coding genes analysed at nucleotide level plus rRNA genes):

The following cladogram is based on a RAxML maximum likelihood phylogram from Anderson & Lindgren 2021:

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Further reading

• abstract

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External links

• The Taxonomicon: Superorder Decapodiformes

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