Bairdoppilata comanchensis ( Alexander, 1929 ) Antonietto & Carmo & Viviers & Neto & Hunt, 2016

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 : 13-14

Bairdoppilata comanchensis ( Alexander, 1929) comb. nov.

Fig. 5 N–P

Bairdia comanchensis Alexander, 1929: 63 , figs 2.15, 3.4.

Bairdia comanchensis – Howe & Laurencich 1958: 66, unnumbered figs. — Moysey & Maddocks 1982: 144, figs 1.2a–b, 4.13–4.14.

Bairdia cf. comanchensis –? Grekoff & Deroo 1956: 217, figs 46.9–46.10.

Bairdia aff. comanchensis –? Neufville 1973: 127, fig. 7.4.3a–b. — Reyment 1981: 142, fig. 2a–b. Bairdia spp. – Rosenfeld & Raab 1974 pars: 6, fig. 1.14. Honigstein et al. 1985 pars: 3, figs 9.94, 9.94. Bairdia pseudoseptentrionalis ( Mertens, 1956) – Shahin 1991: 136, figs 1.16–1.17.

Bairdoppilata aff. pseudoseptentrionalis – Andreu & Bilotte 2006: 60, figs 1.15–1.17.

non Bairdia comanchensis – Swain & Brown 1964: 12, fig. 1.5a–c.

non Bairdia spp. – Rosenfeld & Raab 1974 pars: 6, figs. 1.15–1.16.

New material examined

BRAZIL: 1-US-1 well, Laranjeiras Municipality, Sergipe State (depths of 552, 570, 600, 810, 816 and 840 m); Massapê outcrop, Riachuelo Municipality, Sergipe State (samples MP-1514, MP-1516 to MP- 1520, MP-1522, MP-1542, MP-1543 and MP-1546), approximate coordinates 10°06' S, 37°10' W.

Type locality and stratum

“Station 24”, Johnson County, Texas, United States; upper Denton Formation, upper Albian.

Measurements

Hypotype (CP-674): carapace: length = 0.76 mm, height = 0.49 mm, width = 0.38 mm.

Hypotype (CP-675): right valve: length = 0.75 mm, height = 0.42 mm.

Remarks

The new generic identification for Bairdoppilata comanchensis ( Alexander, 1929) comb. nov. follows Maddocks (1969) and Becker et al. (1989). According to both, the genus Bairdia McCoy, 1844 (to which the present species was first assigned) is restricted to the Paleozoic period; the former also mentions that Bairdoppilata is virtually identical in external view to Bairdia , but presents a series of denticles ahead of both extremities of its hinge in internal view, and is confined to the Cretaceous–Recent. The present authors rely on both statements for the generic change herein performed. Several occurrences (including possible ones) of Bairdoppilata pseudoseptentrionalis Mertens, 1956 ( Shahin 1991; Andreu & Bilotte 2006) are transferred to Bairdoppilata comanchensis comb. nov. based on differences in size and overall external shape from these specimens to the ones assigned by Mertens (1956). One of the specimens identified as Bairdoppilata comanchensis in Swain & Brown (1964 : pl. 1, fig. 5a, c) belongs in fact to B. rotunda ( Alexander, 1929) – see the generic review in Howe & Laurencich (1958); the other one is from an unnamed taxon. The specimen in Neufville (1973), also figured in Reyment (1981), might belong to B. comanchensis comb. nov., despite differences in carapace size and dorsal margin morphology, possibly caused, respectively, by environmental and diagenetic factors. One of the specimens of Bairdia spp. figured in Rosenfeld & Raab (1974: pl. 1, fig. 14) also belongs to the same species, but these authors do not specify its range and geographical distribution, instead grouping it with all the others identified as Bairdia ; this problem was partly solved by Honigstein et al. (1985), who restricted the Bairdoppilata comanchensis specimens to the late Cenomanian–Turonian.

Paleoecology and distribution

Bairdoppilata comanchensis comb. nov. is a transitional to marine (shelf to neritic) species occurring in the following localities and stages: Denton, Walnut (middle Albian) and Weno (Albian) Formations, United States ( Alexander 1929; Howe & Laurencich 1958; Moysey & Maddocks 1982); Raha and Abu Qada Formations, Egypt, Cenomanian ( Shahin 1991); Marnes de la Fontaine Salée and Grès de las Sals Formations, Aquitaine Basin, France, Cenomanian–Turonian ( Andreu & Bilotte 2006); possibly Ora shale, upper part of the ‘En Yorqe'am Member and the Avnon Member, Ḥaẕera Formation; Yotvata Member, in the Negba, Moẕa, Bet Hakerem, Kefar Sha'ul, ‘Isfiya, Khureibe and Daliya Formations; Levantine Basin, Israel, upper Cenomanian–Turonian ( Rosenfeld & Raab 1974; Honigstein et al. 1985); and in the present work, Angico, Taquari and Maruim Members, Riachuelo Formation, Sergipe-Alagoas Basin, Brazil, uppermost Albian, Aracajuia antiqua zone (MSA-1).

Figures

Fig. 5. [facing page] Ostracods of the Riachuelo Formation, Sergipe-Alagoas Basin, Albian, Brazil. – A–C. Cytherella besrineensis (Bischoff, 1964) comb. nov. A. CP-669, right lateral view. B–C. CP-668. B. Left lateral view. C. Dorsal view. – D–F. Conchoecia? sp. 1. D, F. LBP 10. D. Right lateral view. F. Dorsal view. E. LBP 11, left lateral view. – G–I. Cytherelloidea btaterensis Bischoff, 1964. G. CP-671, right lateral view. H. CP-672, left lateral view. I. CP-673, dorsal view. – J. Cytherelloidea aff. globosa Kaye, 1964, CP-756, right lateral view. – K. Cytherella sp. 1, CP-670, lateral view. – L. Bairdoppilata pseudoseptentrionalis Mertens, 1956, CP-676, right lateral view. – M. Bairdoppilata sp. 1, CP-678, right lateral view. – N–P. Bairdoppilata comanchensis (Alexander, 1929) comb. nov., CP-674. N. Left lateral view. O. Right lateral view. P. Dorsal view. – Q–S. Bairdoppilata sp. 2, CP-757. Q. Right lateral view. R. Left lateral view. S. Dorsal view. Scale bars = 100 μm.