Middle Permian ostracods (Crustacea) from the Guadalupe Mountains, West Texas, USA Author Tarnac, Anaëlle D9FF2E72-B3F0-4EC7-ADC2-3F04D27E7E1E Centre de Recherches en Paléontologie - Paris, MNHN - SU - CNRS, 8 rue Buffon, 75005 Paris, France. tarnac.anaelle@gmail.com Author Forel, Marie-Béatrice 063C1F7E-6D26-48F9-A8B1-2AFA496B5FB8 Centre de Recherches en Paléontologie - Paris, MNHN - SU - CNRS, 8 rue Buffon, 75005 Paris, France. marie-beatrice.forel@mnhn.fr Author Nestell, Galina 4343960A-89AF-47A7-8418-6B715A7ED791 Department of Earth and Environmental Sciences, University of Texas at Arlington, Arlington, TX 76019, USA. gnestell@uta.edu Author Nestell, Merlynd 544B3992-191B-4427-B1F7-7A19A9CBCB63 Department of Earth and Environmental Sciences, University of Texas at Arlington, Arlington, TX 76019, USA. nestell@uta.edu Author Crasquin, Sylvie 6FDDD550-8522-404D-B3A2-D30BFAA86927 Centre de Recherches en Paléontologie - Paris, MNHN - SU - CNRS, 8 rue Buffon, 75005 Paris, France. sylvie.crasquin@mnhn.fr text European Journal of Taxonomy 2021 2021-09-22 770 1 60 http://dx.doi.org/10.5852/ejt.2021.770.1499 journal article 4088 10.5852/ejt.2021.770.1499 003a15e3-4b3f-423c-b40b-7f08fa1b1a75 2118-9773 5536263 33F92DB8-3122-4F8E-995B-DBF260B3E390 Geisina culbersonensis Crasquin sp. nov. urn:lsid:zoobank.org:act: FA68573E-E0FA-4DC1-B82E-6F860628863F Fig. 6N–P Diagnosis A species of Geisina with a pustulose carapace, two large spines in the posterior part of the carapace and free margins bordered with small spines. Etymology From Culberson County, West Texas , USA , where the studied samples have been collected. Material examined Holotype USA • complete carapace, ( Fig. 6N ); Guadalupe Mountains , West Texas , Williams Ranch Member , Cutoff Formation , Quarry section, sample GM1; Roadian , Middle Permian ; MNHN.F. F63396 . Paratype USA • 1 complete carapace , ( Fig. 6O ); Guadalupe Mountains , West Texas , Williams Ranch Member , Cutoff Formation , Quarry section, sample GM1; Roadian , Middle Permian ; MNHN.F. F63397 . Additional material USA • 1 complete carapace ; Guadalupe Mountains , West Texas , Williams Ranch Member , Cutoff Formation , Quarry section, sample GM2; Roadian , Middle Permian ; MNHN.F. F63398 • 1 complete carapace , 4 valves ; Guadalupe Mountains , West Texas , Williams Ranch Member , Cutoff Formation , Quarry section, samples GM1, GM2, GM4; Roadian , Middle Permian ; MNHN.F. F63483 . Dimensions L= 602–676 μm; H =430–548 μm; H/L=0.53–0.64. Description Carapace sub-rectangular in lateral view with Hmax in anterior ⅓rd of L and Lmax slightly below mid-H; DB long and straight; ACA=115°–130°, PCA=105°–115°; AB with large radius of curvature with maximum at lower ⅓ rd H; VB nearly straight; PB laterally compressed, large with maximum of curvature located at mid-H; free margins bordered by small spines; L 2 not well visible; S 2 round and clearly marked; L 3 underlined by two large spines, one dorsal and one medio-ventral, pointing upward; surface completely covered with pustules. Occurrence Samples GM1, GM2, GM4, Quarry section, Williams Ranch Member, Cutoff Formation, Guadalupe Mountains, Western Texas , USA , Roadian, Middle Permian (this work). Remarks Geisina culbersonensis sp. nov. has a very particular shape and primary ornamentation. It can be compared with Geisina sp. in Chitnarin et al. 2012 from the Asselian–Sakmarian, Early Permian of Thailand ( Chitnarin et al. 2012 ), which has a smaller PB and a smooth surface.