Taxonomy and Zoogeography of the Mesozoic Cytherurid Ostracoda From West‐central Argentina

Abstract

The status of thirty four species of the cytheroidean ostracod family Cytheruridae from the Neuquén Basin, west-central Argentina is reviewed. These species belong to the following nine genera: Eucytherura Müller, ranging in this study from Pliensbachian to Valanginian and represented by fourteen species; Kangarina Coryell and Fields, Aalenian-Bajocian, with a single species; Acrocythere Neale, Hauterivian, one species; Paranotacythere Bassiouni, Berriasian, two species; Procytherura Whatley, Pliensbachian to Hauterivian, twelve species; Cytheropteron Sars, Aalenian-Bajocian, one species: Eocytheropteron Alexander, Hauterivian, one species; Paradoxorhyncha Chapman, Aalenian-Bajocian, one species; and Paracytheridea Müller, Berriasian, one species. Of the three subfamilies of the Cytheruridae, the Cytherurinae, with thirty species are by far the most numerous and abundant throughout the study. The other two subfamilies, the Cytheropterinae are represented by three species and the Paracytherideinae by a single species of the nominative genus. Several of the species are very widely distributed geographically and have, for example, also been recorded from Europe; others indicate close links with South Africa and Australia. The stratigraphical ranges of certain genera have been extended as a result of this study. For example, Kangarina has not previously been recorded below the Cretaceous. The Cytheruridae are clearly the most diverse cytheroidean ostracodes in the Mesozoic of the Neuquén Basin and are more diverse than all other groups of ostracodes combined. Four new species, Eucytherura tessae, Eucytherura yunga, Procytherura amygdala and Eocytheropteron immodicus are described. Eucytherura guillaumeae nom. nov. for Eucytherura tuberculata Brenner and Oertli and Eucytherura paranuda nom. nov. for Eucytherura nuda (Brand) are proposed.

Past emergent phase of Shatsky Rise deep-marine igneous plateau

“…2d ). Following are the key features that support reconstruction of such nearshore marine environment: (i) assemblage composition dominated by the Family Cytheruridae and with Cytherelloidea , resembling a Jurassic Argentine inner shelf biofacies 15 , 16 ; (ii) abundant occurrence of known seaweed-associated intertidal taxa, Semicytherura and Hemicytherura 17– 19 ; (iii) generally low species-diversity 20 ; and (iv) absence of typical outer neritic or deeper taxa such as Cytheropteron , Argilloecia , trachyleberidids and thaerocytherids (their absence is indicative of shallow [<20 m] depth in specific examples of modern western Pacific coasts) 21 – 23 .…”

Ostracoda and foraminifera from Paleocene (Olinda well), Paraíba Basin, Brazilian Northeast

“…and Eocytheropteron sp.). The Cytheruridae is a diverse and abundant family of marine/brackish water cytheracean Ostracoda (Ramos et al 1999), and in the Mesozoic they seem to have been confined to shelfal depths, with many species also in marginal marine habitats (Ballent and Whatley 2009), a behavior that may have been extended to the Paleocene. Shallower waters in this interval could be inferred not only by the dominance of the benthic ostracods and reduction in plancktonic foraminifera, but also by the increase of SiO 2 and Al 2 O 3 (Nascimento et al 2011).…”

Rhaetian (Late Triassic) ostracods (Crustacea, Ostracoda) from the offshore prolongation of the North Dobrogean Orogen into the Romanian Black Sea shelf

“…This molecular analysis furthermore highlights the basal position of Xylocythere sarrazinae, supporting the hypothesis of an ancient origin of Eucytherurinae. In their revision, Whatley & Boomer (2000) considered a number of Early Mesozoic Cytheruridae as junior synonyms of the extant genus Eucytherura Müller, 1894 and classified this genus within the Cytherurinae, in line with contributions on extent Cytheruridae (e.g., Ayress et al 1995;Ballent & Whatley 2009).…”