Bairdoppilata martyni Coryell, Sample and Jennings, 1935

Maddocks, Rosalie F., 2022, Taxonomic applications of the esophageal flapper valve in Bairdoppilata and Glyptobairdia (Bairdiidae, Ostracoda), with comments on anatomy, ontogeny, and geography, Zootaxa 5175 (3), pp. 301-342 : 325-327

Bairdoppilata martyni Coryell, Sample and Jennings, 1935

( Figures 15J–L )

1935 Bairdoppilata martyni Coryell, Sample and Jennings : 3, text-figs. 1, 2.

? 1942 Bairdoppilata cf. B. martyni Coryell, Sample and Jennings. —Vernon, p. 60–66.

?1964 Bairdoppilata margini [sic] Coryell, Sample and Jennings.—Puri & Vernon, p. 114.

1974 Bairdoppilata martyni Coryell, Sample and Jennings. —Poag, p. 346.

Material Examined: Several fossil valves (including RV specimen 1018 RV, LV specimen 1019LV) in UH 0083, collected from the type locality .

Dimensions: LV specimen 1019LV: LVL 1.057 mm, LVH 0.675 mm; RV specimen 1018RV: RVL 1.060 mm, RVH 0.647mm. Coryell, Sample & Jennings (1935) reported carapace length 1.030 mm, carapace height 0.68 mm.

Anatomical Remarks. The valves are smooth, lacking puncta. In lateral outline the LV is rounded-subtriangular, with the greatest height being located at about one-third of length ( Fig. 16L ). The posterior angle is located rather low, at about one-quarter of height. Supplemental dentition is well developed in these specimens. Nothing is known of the flapper valve or other soft anatomy in this fossil species.

A distinctive patch pattern is preserved ( Figs. 15J–L ), which does not resemble any modern species of the Gulf Coast and Caribbean. It features a shield-shaped, central opaque spot, which is connected by three or more narrow bridges to a broad opaque expanse covering the dorsal margin and the posterior region. Numerous clear, circular islands are located within this posterior opaque region. A familiar spot is present at the anterior corner, but the crescentic vertical streak in the central-anterior region has no analogue among the living Caribbean species.

Taxonomic Remarks: Photographs of topotype specimens of this species are offered here, to supplement the drawings that accompanied the original published description.

Howe & Law (1936, p. 28) compared their new species B. taxodonta to B. martyni , stating: “The closely related B. martyni of the Lower Chickasawhay may not be separated easily from B. taxodonta in exterior view, but from the interior it shows a more delicate carapace with thinner, narrower margins and a more delicate hinge. Translucent specimens usually show three vertical cloudy areas instead of one, and the inner edge of the hinge line is decidedly angulate instead of being broadly rounded.”

Poag (1974) reported that B. martyni occurs consistently but in low numbers at six exposures of the Chickasawhay Formation and the overlying Paynes Hammock Formation, in southeastern Mississippi and Alabama. These units belong to the Chickasawhayan Local Stage of early Late Oligocene age. He did not find it in the underlying Byram Marl and Bucatunna Formations. The species has also been reported from the Suwannee Limestone of the Florida Panhandle ( Vernon 1942, Puri & Vernon 1964).

Figures

FIGURE 15. A–I, Bairdoppilata sp. 2 [of Morais & Coimbra 2017, Brazil]. A–D, female specimen 3991F: A, right exterior of whole animal before dissection, in transmitted light, with median eye in anterodorsal region, immature eggs in posterodorsal region; B, LV exterior, damaged, showing AMS and sensilla; C, LV exterior, with AMS and sensilla; D, A2 distal claws. E–G, female specimen 3987F: E, A2 distal claws; F, left side of soft body before dissection, with large median eyes, food balls in gut, and eggs in oviducts; G, genital lobe. H–I, female specimen 3988F: H, LV interior, torn, with AMS and sensilla; I, LV interior, showing AMS and texture of smooth valve. J–L, Bairdoppilata martyni Coryell, Sample and Jennings [Oligocene, Mississippi]: J–K, specimen 1018RV: J, RV exterior in reflected light, showing patch pattern, note occasional clear circles around largest NPC; K, RV exterior in transmitted light, showing patch pattern and NPC. L, specimen 1019LV: LV exterior in transmitted light, showing patch pattern, note occasional clear circles around largest NPC. Scale bar = 50 µm.

FIGURE 16. A, B, Bairdoppilata scaura Maddocks [Hawaii]: A, male specimen 3860M: esophageal plate. B, male specimen 3864M: left lateral view of mouth region, with upper and lower lips, atrium, esophagus, U–shaped strut of upper lip, ciliate hemispherical mound of lower lip, flagellate seta projecting into atrium, and setules of forehead and sternum. C, Bairdoppilata sp. 2 [of Maddocks 2015, Hawaii]: female specimen 3969F: esophageal valve with ring, collar, belt and plate. D, Bairdoppilata sp. 3 [of Maddocks 2015, Hawaii]: female specimen 3923F: esophageal valve with collar, plate, bracket, and basal ends of braces. E, Bairdoppilata sp. 4 [of Maddocks 2015, Hawaii]: female specimen 3963F: esophageal plate with bracket. F–I, Bairdoppilata sp. 2 [of Morais & Coimbra 2017, Brazil], female specimen 817F: F, A2 claws; G, esophageal plate and bracket; H, both braces; I, genital lobe. Scale bar = 50 µm.