ORDER BATHYTEUTH IDA LINDGREN, 2010

(NINE SPECIES)

Diagnosis: Small adult-sized muscular squids without a cornea covering the eyes; with suckers on the buccal membrane; without circularis muscles in the arm and tentacle suckers; tentacles usually without carpal locking apparatus; tentacle club not divided into manus and dactylus, club suckers in more than seven series; straight funnel–mantle locking apparatus, reaching the anterior margin of the mantle; gladius with a spoon-like conus; oviducts paired; without accessory nidamental glands; gills with branchial canal; with duplications of the mitochondrial genes atp6, atp8, cox1, cox2, cox3 and trnD.

Remarks: The clade formed by the families Bathyteuthidae and Chtenopterygidae is commonly referred at the superfamily level ( Bathyteuthoidea Pfeffer, 1900; e.g., Young & Vecchione, 2016b; Strugnell et al., 2017) or at the order level, usually referred as order Bathyteuthida (e.g. Allcock et al., 2015; MolluscaBase eds. 2021c). Lindgren (2010) confirmed the sister-taxon relationship of this clade with the order Oegopsida and designated it as the order Bathyteuthoidea . We agree with the treatment of this group at the ordinal level, but we have changed the ordinal suffix from ‘-oidea’ to ‘-ida’. Although Article 29.2 of the International Code of Zoological Nomenclature (ICZN, 1999) states that the suffix for the superfamily level is ‘-oidea’, the code does not regulate ordinal level names. We decided to change the original spelling of Lindgren (2010) by adjusting it to ‘-ida’, the conventional cephalopod ordinal level ending, to avoid further confusion regarding the rank at which this clade should be treated.