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

Abstract

AbstractBryozoans with calcified frontal shields formed by the fusion of costae, collectively constituting a spinocyst, are traditionally assigned to the family Cribrilinidae. Today, this family is regarded as nonmonophyletic. In the Argentine Cenozoic, cribrilinids were until recently represented by only two fossil species from the Paleocene of Patagonia. This study describes the first fossil representatives ofJolietinaandParafigularia:J. victorian. sp. andP. pigafettain. sp., respectively. A fossil species ofFigularia,F. elcanoin. sp., is also described. The material comes from the early Miocene of the Monte León and Chenque formations (Patagonia, Argentina). For comparison, we also provide redescriptions of the remaining extant species ofJolietina:J. latimarginata(Busk, 1884) andJ. pulchraCanu and Bassler, 1928a. The systematic position of some species previously assigned toFigulariais here discussed.Costafigularian. gen. is erected, withFigularia pulcherrimaTilbrook, Hayward, and Gordon, 2001 as type species. Two species previously assigned toFigulariaare here transferred toCostafigularia, resulting inC. jucundan. comb. andC. tahitiensisn. comb. One species ofFigulariais reassigned toVitrimurella, resulting inV. amplan. comb. The family Vitrimurellidae is here reassigned to the superfamily Cribrilinoidea. The subgenusJuxtacribrilinais elevated to genus rank.Inferusiais regarded as a subjective synonym ofParafigularia.Parafigularia darwiniMoyano, 2011 is synonymized withI. tayloriKuklinski and Barnes, 2009, resulting inParafigularia taylorin. comb. Morphological data suggest that these genera comprise different lineages, and a discussion on the disparities among cribrilinid (sensu lato) spinocysts is provided.UUID:http://zoobank.org/215957d3-064b-47e2-9090-d0309f6c9cd8