Three new cribrimorph bryozoans (order Cheilostomatida) from the early Miocene of Argentina, with a discussion on spinocystal shield morphologies

LÓPEZ-GAPPA, JUAN; PÉREZ, LEANDRO M.; ALMEIDA, ANA C.S.; ITURRA, DÉBORA; GORDON, DENNIS P.; VIEIRA, LEANDRO M.

JOURNAL OF PALEONTOLOGY

PALEONTOLOGICAL SOC INC

Año: 2021 vol. 95 p. 1 - 15

0022-3360

Bryozoans with calcified frontal shields formed by the fusion of costae, collectivelyconstituting a spinocyst, are traditionally assigned to the familyCribrilinidae. Today, this family is regarded as nonmonophyletic. In theArgentine Cenozoic, cribrilinids were until recently represented by only twofossil species from the Paleocene of Patagonia. This study describes the first fossil representatives of Jolietina and Parafigularia: J. victoria n. sp. and P. pigafettai n. sp., respectively. A fossil species of Figularia, F. elcanoi n. sp., is also described. The material comes from the early Miocene ofthe Monte León and Chenque formations (Patagonia, Argentina). For comparison,we also provide redescriptions of the remaining extant species of Jolietina: J. latimarginata (Busk, 1884) and J. pulchra Canu and Bassler, 1928a. The systematic position of some species previouslyassigned to Figularia is here discussed. Costafigularia n. gen. is erected, with Figularia pulcherrima Tilbrook, Hayward, and Gordon, 2001 as type species. Twospecies previously assigned to Figularia are here transferredto Costafigularia, resulting in C. jucunda n. comb. and C. tahitiensis n. comb. One species of Figularia is reassigned to Vitrimurella, resulting in V. ampla n. comb. The familyVitrimurellidae is here reassigned to the superfamily Cribrilinoidea. Thesubgenus Juxtacribrilina is elevated to genus rank. Inferusia is regarded as a subjective synonym of Parafigularia. Parafigularia darwini Moyano, 2011 is synonymized with I. taylori Kuklinski and Barnes,2009, resulting in Parafigularia taylori n. comb. Morphological data suggest that these genera comprise differentlineages, and a discussion on the disparities among cribrilinid (sensu lato) spinocystsis provided.