Superfamily PLECTOPYRAMIDOIDEA Haecker, 1908 n. stat.

Plectopyramididae Haecker, 1908: 157 .

Acropyramidoidea – Petrushevskaya 1981: 99-103 [nomen dubium]; 1986: 133-135. — Afanasieva et al. 2005: S293. — Afanasieva & Amon 2006: 140.

Acropyramidoida – Amon 2000: 57-58 [nomen dubium, as an order].

DIAGNOSIS. — Two segments with no, to very weak, constriction between the cephalis and thorax. The cephalis is very small, while the thorax is very long, or very wide resembling a shallow-depth hat. Thoracic pores are systemically distributed throughout the segment.

REMARKS

This superfamily consists of two Cenozoic families:the Lampromitridae (questionably included) and the Plectopyramididae . The inclusion of Lampromitridae in this superfamily is questionable (see remarks in Lampromitridae). It is not necessary to prioritize a questionably assigned family name for a valid superfamily name in order to use “ Plectopyramidoidea ” as a valid name. Sandin et al. (2019) commented the high 28S rDNA gene in deep ocean forms of “ Plectopyramidoidea ” (originally Acropyramidoidea). This contract the idea that the Lampromitridae are generally found in shallow water. The “molecular Plectopyramidoidea ” may not include the Lampromitridae .