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    Bicornucandona gen. nov., sp nov (crustacea, ostracoda) from finegan springs (Texas, USA)
    (Magnolia Press, 2011) Külköylüoğlu, Okan; Gibson, Randy; Diaz, Peter H.; Colin, Jean-Paul
    A new freshwater ostracod genus, Bicornucandona gen. nov. and its type species (Bicornucandona fineganensis sp. nov.) are described from Finegan Springs, Texas, U. S. A. The new genus differs from the related genera in the presence of two horn-like structures on the dorsal margin of the left valve in both sexes. This is also the diagnostic character of the type species. Differences in the structure of the hemipenes and prehensile palps of the male, and the shapes of some other soft body parts also separate this genus from the related species. Taxonomic status of the new genus and species are compared and discussed with both living and fossil relatives.
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    A new genus, Tuberocandona gen. nov. (Crustacea, Ostracoda, Candonidae) and past to present ostracod species diversity in Texas (USA)
    (Int Soc Subterranean Biol, 2023) Külköylüoğlu, Okan; Ataman, Alper; Gibson, Randy; Diaz, Peter
    A new ostracod genus, Tuberocandona gen. nov., was collected from Honeycut Hollow Springs, Texas, USA Morphological comparisons and cladistic analyses showed that the new genus displays several dif-ferent features (e.g. presence of two tubercules on each of the valves, numbers of A1 segments, shape of A2 claws, shape and presence of two claw-like setae on the clasping organs, absence of d2 and dp setae on T2 and T3, absence of alpha and beta setae on Md, shape of hemipenis) from other genera of the tribe. Including the new species, the number of non-marine ostracods known from inland waters of Texas is now 118 species in 45 genera. With the aim of documenting ostracod biodiversity in Texas (USA) by including fossils, we sought documents published from 1927 to 2022 and were able to list 673 ostracod taxa belonging to 142 genera. Among the fossils, 73 ostracods were the oldest records during the Penn-sylvanian period (ca. 310 mya), while there were only 42 taxa reported from the Holocene. The Eocene had the highest number of ostracods (126 taxa). In comparison, the living species had only 18 of 673 taxa that were considered nonmarine forms. There are only six species in common with the fossils and recent records. These results suggest the potential for relatively high ostracod species richness and diversity in Texas. This is indeed strongly supported by the present study and the described new genus and its type species (Tuberocandona leonidasi sp. nov.).
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    A new Ostracoda (Crustacea) genus, Comalcandona gen. nov., from Texas, USA
    (2018) Külköylüoğlu, Okan; Gibson, Randy
    A new freshwater ostracod genus, Comalcandona gen. nov., and its type species (Comalcandona tressleri sp. nov.) are described from John Knox Ranch, Comal County, Texas, USA. The new genus differs from the related genera in the presence of the shallow pits on the trapezoidal shape of the carapace and presence of one well-developed anterior claw (posterior claw and both anterior and posterior setae are absent) on the uropod, a diagnostic character. Differences in the structure of the hemipenes, length and numbers of setae on the extremities, and shape of some other soft body parts also separate this genus from the other related genera. The taxonomic status of the new genus and species are compared and discussed with other related groups.
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    On Schornikovdona gen. nov (Ostracoda, Candonidae) from rheocrene springs in Texas (USA)
    (Brill Academic Publishers, 2017) Külköylüoğlu, Okan; Yavuzatmaca, Mehmet; Akdemir, Derya; Diaz, Peter H.; Gibson, Randy
    A new candonid genus, Schornikovdona gen. nov., with its type species Schornikovdona bellensis sp. nov., is described from rheocrene springs of Bell County, Texas. It is designated to the tribe Candonini due to the smooth carapace surface, normal pore openings with sensory seta, the presence of a 5-segmented first antenna, two long sexual bristles on the second antenna in males, the narrowly fused terminal segment of the Md palp, a long penultimate segment of the Mxl palp, two long and one short setae on the terminal segment of T3, the absence of an "e" seta on T3, the presence of a posterior seta on the uropod, the presence of 5 + 2 rows of spines on Zenker's organ, and other characteristics found in the tribe. The main diagnostic characteristics separating the new genus from the other genera in the tribe are the shape of the carapace, the reduced numbers of segments in the first antenna, reduction or absence of exopodial setae in the second antenna, asymmetrical clasping organs, the uropod with one rod-shaped claw, the different shape of the hemipenis, and differences in parts of the chaetotaxy. Based on these differences, we propose Schornikovdona gen. nov. as a new genus, with the new species S. bellensis sp. nov., in the subfamily Candoninae in the family Candonidae.