Xestoleberis, Sars, 1866

Antonietto, Lucas Silveira, Carmo, Dermeval Aparecido do, Viviers, Marta Claudia, Neto, João Villar Queiroz & Hunt, Gene, 2016, Ostracoda (Arthropoda, Crustacea) from the Riachuelo Formation, Sergipe-Alagoas Basin, Brazil, Upper Aptian-Albian, European Journal of Taxonomy 244, pp. 1-57 : 27-28

Xestoleberis ? sp. 1

Fig. 6U

Material examined

BRAZIL: 1-US-1 well, Laranjeiras Municipality, Sergipe State (depths of 480, 552, 554.5, 1080 and 1086 m); Massapê outcrop, Riachuelo Municipality, Sergipe State (samples MP-1518, MP-1534, MP- 1544, MP-1545 and MP-1547), approximate coordinates 10°06' S, 37°10' W.

Measurements

Hypotype (CP-761): carapace: length = 0.37 mm, height = 0.17 mm.

Remarks

The present specimens share the typical morphology of Xestoleberis Sars, 1928 : a small and smooth carapace, with greatest width at the postero-dorsal region. None of the specimens collected are disarticulated, and thus none of their internal features can be observed. According to Kempf (1986), more than 300 taxa have been described and assigned to this genus, despite its quite conservative shell morphology and the fact that it was originally described based on soft part morphology ( Puckett et al. 2012). Many papers describe, identify or partially identify Xestoleberis species in the Cretaceous ( Veen 1936; Bonnema 1941; Schmidt 1948; Benson & Tatro 1964; van den Bold 1964; Holden 1964; Crane 1965; Herrig 1966; Rosenfeld & Raab 1974; Dingle 1980; Weaver 1982; Damotte & Fleury 1987; Ismail & Soliman 1997; Gebhardt 1999; Morsi et al. 2008; Piovesan et al. 2009, 2013; Tesakova 2010; Babinot & Colin 2011; Puckett et al. 2012). For these reasons, the species observed from the Riachuelo Formation is left in open nomenclature, as Xestoleberis ? sp. 1.

Paleoecology and distribution

Xestoleberis ? sp. 1 is a marine, shelf species occurring in the Maruim Member, Riachuelo Formation, Sergipe-Alagoas Basin, Brazil, uppermost Albian, Aracajuia antiqua zone (MSA-1).