Taxonomic applications of the esophageal flapper valve in Bairdoppilata and Glyptobairdia (Bairdiidae, Ostracoda), with comments on anatomy, ontogeny, and geography.

The esophageal valve follows a uniform design in species of Bairdoppilata and Glyptobairdia, having a thin, wedge-shaped plate with 1016 small teeth along the posterior edge. This structure may be added to the list of diagnostic anatomical traits, including the scissors-like antennal claws and complex distal appendages of the hemipenis, for identification of living species of these genera. These soft anatomical characters are invariably associated with bairdoppilatan supplemental dentition on the carapace, which supports the reliability of that trait for identification of fossils.

Taxonomic applications of the esophageal flapper valve in the Genus Neonesidea (Bairdioidea, Podocopida, Ostracoda), including descriptions of new and poorly known species from the Caribbean and Gulf of Mexico.

Species and genera of Bairdiidae can be difficult to discriminate, because of the somewhat limited morphological range of the carapace and limbs and the prevalence of homeomorphy. Attention to the esophageal flapper valve, an uncalcified but relatively well sclerotized structure, may contribute to more reliable identifications. Living species of Neonesidea exhibit sufficient variability in the architecture of this structure to suggest that it may have taxonomic value.

Flapper Valve and Hayfork: Functional anatomy and taxonomic potential of the Gastric Mill of Bairdioidea (Ostracoda, Podocopida).

The chewing apparatus of the Bairdioidea has been described just once and is rarely illustrated, but it might have more taxonomic significance than commonly supposed. It is constructed as a flapper valve (hinged check valve), which is unique among Ostracoda and unusual among animals. It projects into the midgut and is substantially enveloped by it.

New and poorly known species of Bairdoppilata and Paranesidea (Bairdiidae, Ostracoda) from French Frigate Shoals and O'ahu, the Hawaiian Islands.

Bairdoppilata scaura, n. sp. and five species of Bairdoppilata and Paranesidea in open nomenclature are described from encrusting communities on French Frigate Shoals and Kane'ohe Bay, Oahu, Hawaiian Islands.

New and poorly known species of Neonesidea (Bairdiidae, Ostracoda, Crustacea) from French Frigate Shoals, the Hawaiian Islands.

Neonesidea tenera and four new species (N. plumulosa, N. holdeni, N.