Bairdianella cuspis Buschmina 1970

• Main Authors: Guillam, Elvis, Forel, Marie-Béatrice, Song, Junjun, Crasquin, Sylvie
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2022
• Subjects: Biodiversity; Taxonomy; Animalia; Arthropoda; Ostracoda; Podocopida; Bairdiidae; Bairdianella; Bairdianella cuspis; Pechora
• Online Access: https://doi.org/10.5281/zenodo.6369147; http://treatment.plazi.org/id/03C687C56413FFBCFD9DF3C24D3AC388

Bairdianella cuspis Buschmina, 1970 Fig. 11P Bairdianella cuspis Buschmina, 1970: 73, pl. V fig. 2. Bairdianella cuspis – Kotschetkova & Janbulatova 1987: pl. 24 fig. 1. — Zhuravlev & Sobolev 2019: figs 4i–j. – Sobolev 2020: figs 5–10. Material examined CHINA • 1 complete carapace (Fig. 11P); Blue Snake section, Tangbagou Formation, sample 19BAI 03; P6M 3973 • 25 complete carapaces; Blue Snake section, Tangbagou Formation, samples 19BAI 01-03, 19BAI 05, 19BAI 37, 19BAI 39, 19BAI 44. All from the Tournaisian, early Carboniferous. Dimensions RV: L = 460–575µm, H = 188–247µm, H/L = 0.37–0.45. LV: L = 460–587 µm, H = 201–255 µm, H/L = 0.38–0.48. Remarks Our material is smaller than the holotype shown in Buschmina (1970: pl: 5 fig. 2) with L = 625µm, H = 325 µm, H/L = 0.52. Specimens shown in Kotschetkova & Janbulatova (1987: pl. 24 fig. 1) from Mugodzhary, Western Kazakhstan and Sobolev (2020: figs 5, 9–10)) from Pechora Uplift, Russia, have a similar size to our material with respectively L = 532µm, H = 250 µm and H/L = 0.47 and L = 580µm, H = 280 µm, H/L = 0.48. However, the specimen shown in Zhuravlev & Sobolev (2019) from North Ural is slightly larger than the present material with L = 580µm, H = 275µm and H/L = 0.47 but still smaller than the holotype in Buschmina (1970). The size variations in our material indicate that at least two stages are present and may correspond to juveniles, compare to the holotype in Buschmina (1970), but the wide distribution of the dimensions of the specimens does not allow to clearly discriminate them. Five species have been mentioned as Bairdianella aff. cuspis in papers discussing Devonian– Carboniferous ostracod faunas, they are summarized in Table 3. Based on specimens shown in these different contributions, the main differences between these species and Bairdianella cuspis Buschmina, 1970 seem to be weak variations of the length of the carapace, concavity at VB, degree of postero-dorsal angulation, posterior end more or less rounded and AVB sometimes truncated ...