Genus Perissocytheridea Stephenson, 1938

Type species: Perissocytheridea matsoni Stephenson, 1938

Remarks: Specimens attributed to the genus Perissocytheridea found in Cretaceous strata have been reported by several authors (Swain & Brown, 1964; Piovesan et al. 2014a, b; Piovesan et al. 2015; Trabelsi et al. 2021). Nogueira & Ramos (2016), showed the distribution of Perissocytheridea over geological time according to the global record and emphasized the need for studies that prove the relationship between species attributed to the Cretaceous and species found in the present. Specimens analyzed in the present study were attributed to this genus since the morphological characteristics related to the carapace are similar, that is, they have small and fragile carapaces, are subpiriform, with a straight but angled dorsal margin, have a slightly convex ventral margin, a broadly rounded anterior margin, a posterior margin presenting a posterodorsal caudal process, and a reticular surface (with pits and ridges), but are sometimes smooth. The ocular tubercle is small but visible.