Bairdoppilata sp. 2

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 : 328-329

Bairdoppilata sp. 2 [of Morais & Coimbra 2017, Brazil]

( Figures 15A–I , 16F–I )

2017 Bairdoppilata sp. 2 : Morais & Coimbra, fig. 3E.

Material Examined. Five specimens from Saco do Francisco, Brazil.

Dimensions: Specimen 3991F, LVL 0.974 mm, LVH 0.672 mm. Specimen 3988F, RVL 0.91, RVH 0.509.

Esophageal Valve: The plate is flat, broadly wedge-shaped, and furnished with about 14 evenly spaced triangular teeth ( Fig. 16G ). The scroll-like indentations on the anterior edges are well marked. The bracket consists of two curving triangular walls arranged in a V, with conspicuous tubercles along their anterior ends. The braces have thick shafts and rather short, blunt aprons ( Fig. 16H ).

Anatomical Remarks: In lateral view the dorsal margin of the carapace arches to unusually great height, the posterior end is not caudate, and the surface is entirely smooth ( Figs. 15A–B, H ).

The distal antennal claws are short, saber-like and sharply pointed, with the anterodistal claw being slightly thinner than the main claw ( Figs 15D–E ). The fused claw is smooth. The eye is unusually large and dark red ( Fig. 15A, F ).

Taxonomic Remarks: Morais and Coimbra (2017) collected empty valves (interpreted as allochthonous) of B. sp. 2 in turf algae of rocky shores immediately below low tide (1–3m) in Santa Catarina State, southern Brazil. They pointed out, correctly, that the taxonomic composition of phytal assemblages of rocky shores is poorly known, echoing similar comments by Maddocks (2013). Then, they characterized Bairdoppilata as a “shelf genus, which lives mainly on sandy sediments,” and they expressed surprise at finding these valves captured by algal turf. This illustrates a familiar paleoecological dilemma: It is easy to equate the site of collection with the habitat in life, forgetting that most species are known only from subfossil valves collected in sea-floor sediments, after post-mortem transport and mixing by sedimentary and taphonomic processes.

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.