FAMILY SCALPELLIDAE PILSBRY, 1907

Modified diagnosis

Scalpellomorphs that possess a maximum of 14 plates (carina, rostrum, paired scuta, terga, upper latera, carinolatera, rostrolatera, and inferior median latera), rarely 13, by secondary loss of the rostrum.

Remarks

This definition works effectively for all known living and fossil forms, with the exception of the highly derived Scalpellopsis striatociliata Broch, 1922 . The record of a subcarina in the Cretaceous species Diotascalpellum fossula (Darwin, 1851b) by Hébert (1855) and Withers (1935) is not substantiated by a re-examination of the material. The family appears in the Aptian (Early Cretaceous, about 120 Mya), and is represented by abundant fossil and living forms. In the Cretaceous and the Palaeogene, species were common in shallow and deep marine environments, with palaeodepths of as little as 20– 30 m. Neogene and present-day records are almost exclusively from the deep sea. The present study identifies two groups, which are taken as subfamilies.