New Ostracod Species Research Articles

Новый вид остракод рода Leperditia из силурийских отложений западного склона Приполярного Урала

The article describes a new species of ostracods of the genus Leperditia from the Upper Silurian deposits of the western slope of the Subpolar Urals (Shchugor River basin). Leperditia unituber Saldin sp. nov. differs from all other species of Leperditia by the presence of a tubercle near the ventral margin of the right valve, a stable diagnostic character.
 The shell is truncated-oval, elongated, widening towards the posterior end. The ventral margin is gently and asymmetrically arched. Longitudinal axis at a slight angle to the length. A narrow marginal border is observed along the ends of the shell. The posterior dorsal swelling on the left valve is pronounced. On the right valve near the ventral part, where the greatest height of the shell is observed, there is a tubercle or spiny outgrowth.

Three new species of the genera Loxoconcha and Xestoleberis (Crustacea, Ostracoda, Podocopida) from central and southern Vietnam

The present study reports three new species of Ostracoda, Loxoconcha damensis sp. nov., Xestoleberis vietnamensis sp. nov. and X. munensis sp. nov., from Phu Quoc Island, southwest Vietnam and Nha Trang Bay, central Vietnam. These species inhabit the coral reefs around isolated islands and can be easily distinguished from other known species based on their morphological differences, mainly in the male copulatory organ. Loxoconcha damensis sp. nov. belongs to Loxoconcha Group A, based on the distributional pattern of their pore system below the eye tubercle. Similarly, based on a combination of morphological types of pore systems, the two new Xestoleberis species belong to Xestoleberis Group A, because these species have two types of pore systems, i.e., sieve-type and lip-type. To the best of our knowledge, this study is the first report on Xestoleberididae and the second on Loxoconchidae from the Recent of Vietnam.

Detailed biostratigraphic scales as based on the palaeobiogenetical approach (an example of the Upper Bajocian – Lower Bathonian ostracod scale of the Russian Platform)

Two new species of ostracods of the family Progonocytheridae Sylvester-Bradley Camptocythere (C.) lateres Tesakova et Shurupova, sp. nov. and C. (C.) angustius Tesakova et Shurupova, sp. nov. from the Michalskii and Besnosovi ammonite zones (Upper Bajocian – Lower Bathonian, Middle Jurassic) of the Sokur section (Saratov) are described. The changes in ontogenesis in the phylogeny of Camptocythere (C.) lateres Tesakova et Shurupova in the stratigraphical interval corresponding to the Palaeocytheridea kalandadzei ostracod Zone, and especially to the beds with C. (C.) lateres, have been studied. The levels of the change in the predominant type of sculpture (corresponding to evolutionary boundaries) are recognized in the sculpture development among the adult representatives of the species in its phylogeny. This palaeobiogenetic (heterochrony) approach allows subdivision of the beds with C. (C.) lateres into three stratigrapical intervals characterized by changes in the type of sculpture.

New Upper Cretaceous Limnocytheridae (Ostracoda, Crustacea) from Argentina

Five new species of ostracods, Paralimnocythere musacchioi n. sp., Paralimnocythere aucamahuevoensis n. sp., Wolburgiopsis ballentae n. sp., Looneyellopsis multiornata n. sp. and Vecticypris punctata n. sp. are described. The significant number of Limnocytheridae taxa shows the importance of the family in brackish to freshwater Campanian-Maastrichtian sediments of the Allen and Loncoche Formations (Neuquén Basin, Argentina) and provide new paleogeographic and biostratigraphic data of each genera. Our results extend the paleogeographic and biostratigraphic range of the genera. Looneyellopsis has a widespread geographic range through Late Cretaceous, and documents affinities with associations from Southern Europe of the same age. Vecticypris is the only genus of Timiriaseviinae which is represented, so far, in the uppermost Cretaceous deposits of the Neuquén Basin.Anew species of Wolburgiopsis confirms the great significance of this genus in the Upper Cretaceous.

Three new species of the genus Loxoconcha (Crustacea, Ostracoda, Podocopida) from the Okinawa Islands, southern Japan.

Three new species of Ostracoda, Loxoconcha noharai sp. nov., L. santosi sp. nov. and L. sesokoensis sp. nov., are described from the Okinawa Islands, southern Japan. The two species Loxoconcha noharai sp. nov. and L. santosi sp. nov. live in estuaries, whereas the species L. sesokoensis sp. nov. lives in coral reefs. These species can be easily distinguished from other previously described Loxoconcha species by their morphological differences, mainly in the male copulatory organ, and distribution pattern of their pore systems. In addition, L. sesokoensis sp. nov. is suggested to be phylogenetically apart from any other Loxoconcha species which have been reported so far from Japan and the adjacent seas.

New cytheracean ostracod fossils from the Plio-Pleistocene Seogwipo Formation of the Jeju Island, Korea

A new genus and two new species of ostracods are described from the Plio-Pleistocene Seogwipo Formation of the Jeju Island, Korea. In this study, Tamnacythere is erected as a new genus, and Tamnacythere seogwipoensis and Kotoracythere paiki are erected as new species. These two new species are the extinct cryophilic ostracods occurring only from the late Pliocene and early Pleistocene strata which are distributed around the Seogwipo area of the Jeju Island, Korea as well as the coastal areas on the East Sea (Sea of Japan) side of central and northern Honshu and southern Hokkaido, Japan.

New ostracodes of the families Loxoconchidae and Trachyleberididae from the Barremian-Albian of southwestern Crimea

New species of ostracodes of the families Loxoconchidae Sars, 1925 and Trachyleberididae Sylvester-Bradley, 1948 are described from the Upper Barremian-Albian sediments of southwestern Crimea. Loxoella? macrofoveata sp. nov. and L.? microfoveata sp. nov. belong to the family Loxoconchidae. Exophthal-mocythere posteropilosa sp. nov. belongs to the family Trachyleberididae.

Description of two new species of ostracods from the Strait of Messina (central Mediterranean)

ABSTRACT More than 100 years after the studies of G. Seguenza, sediment samples from the Strait of Messina (central Mediterranean) were examined in order to study their ostracod faunas. Two new species, Anchistrocheles seguenzai n. sp. and Phlyctocythere sicula n. sp., were found, both in thanatocoenoses from the Bathyal zone, at a depth of 545 m. Anchistrocheles seguenzai n. sp. is distinguishable from A. tenera (Breman, 1975), the only living species of the genus in Recent Mediterranean, and from the other species of the genus because of the more reniform-subquadrangular outline of its carapace and the different height/length ratio values. In the same way, Phlyctocythere sicula n. sp. can be distinguished from P. pellucida (Muller, 1894) the only living species of the genus in Recent Mediterranean, because of its more rounded outline, less marked caudal process which is more obtuse and more shifted to the median side of the posterior end, the inflated postero-ventral area, the more acute anterior margin...

First Middle Ordovician ostracods from western Avalonia: paleogeographical and paleoenvironmental significance

Two new species of ostracods, Conchoprimitia cassidula n. sp. and Sorornanopsis avalonensis n. gen. n. sp., represent the first described Middle Ordovician ostracods from western Avalonia. They were recovered as phosphatized carapaces dissolved out of a late early Darriwilian (ca. 467 Ma) limestone boulder from the Triassic Lepreau Formation of New Brunswick, Canada. The ostracods form a low-diversity component of a higher energy, near-shore, shelf marine fauna dominated by the trilobites Neseuretus and Stapleyella and by the conodonts Drepanoistodus and Baltoniodus. The low diversity of this Avalonian ostracod fauna contrasts with more diverse (tens of species), coeval ostracod faunas from Laurentia and Baltica. The association of Darriwilian ostracods and trilobites from New Brunswick demonstrates continuing exchange of open marine, cool water biota between Avalonia, Baltica, and West and North Gondwana that began in the late early Cambrian.

Lower Cretaceous nonmarine ostracodes from an Escucha Formation dinosaur bonebed in eastern Spain

Three new species of ostracodes are reported from the dinosaur-bearing Escucha Formation at Ariño in Eastern Spain (Iberian Range): Rosacythere denticulata sp. nov., Theriosynoecum escuchaensis sp. nov. and Theriosynoecum arinnoensis sp. nov. Associated charophyta include Clavator harrisii harrisii and Clavator harrisii zavialensis indicating a Lower Albian age, therefore extending the stratigraphic range of the genus Theriosynoecum into the Albian in southern Europe. The environment of deposition for the dinosaur bonebed is interpreted as permanent lacustrine given the association of limnic ostracodes and charophytes.

New Insights into the Early Diversification of the Ostracoda: Tremadocian Ostracods from the Cordillera Oriental, Argentina

New species of ostracods from the Tremadocian in the northwest region of Argentina are described. These are among the earliest well-documented records of ostracods, which shed new light onto the early diversification of the group. The described fauna consists of seven species, five of which are new: Saltite uchuy sp. nov., Saltite kuraq sp. nov., Conchoprimitia? iglesiasi sp. nov., Orechina violetae sp. nov., and Orechina catalinae sp. nov. The fauna consists primarily of soanellids, a non-dimorphic family of palaeocopids, and of binodicopids. One factor leading to diversification of the group in this region may have been the complex configuration of the northwest basin, which had a restricted pattern of circulation. The distribution of the first ostracods is largely restricted to Gondwana and peri-Gondwana regions. Accordingly, it is possible to envision that the origin or at least an important radiation of the group was centred in this region. Both the Soanellidae and the genus Orechina would have origi...

Early Ordovician ostracods from Argentina: their bearing on the origin of binodicope and palaeocope clades

New species of ostracods are described from the Tremadoc of the Cordillera Oriental (Argentina). These are among the earliest well-documented records of Ostracoda sensu stricto. The ostracod assemblages are sourced from shallow marine clastics and are dominated by palaeocopes (Eopilla waisfeldaen. sp.,Nanopsis coquenan. sp.), and the binodicopeKimsella luciaen. gen. and sp.EopillaandKimsellashow affinities with species from paleocontinental Gondwana (e.g., Ibero-Armorica, Turkey, Australia, Carnic Alps), butNanopsisis previously known only from paleocontinental Baltica. This study confirms that two of the major clades of Ordovician ostracods, namely the Binodicopa and the Palaeocopa, were already geographically widespread during the late Tremadoc, suggesting a still earlier origin for these groups, possibly from within the Cambrian to Early Ordovician Bradoriida. Evidence from soft-part anatomy indicates that phosphatocopids, the other group hypothesized to be ancestral ostracods, have apomorphies that preclude them as direct ancestors. The origin of ostracods is more likely to be found within the Bradoriida, a probable polyphyletic group that resembles Early Ordovician ostracods in the external sculpture of their bivalved carapace. Evidence from carapace morphology suggests that the ancestors of true ostracods might lie within the bradoriid groups Beyrichonidae and Hipponicharionidae, a hypothesis that can only truly be tested when more evidence from fossilized soft tissues becomes available.

Two new species of Ostracoda from hydrothermal vents of Riftia pachyptila aggregations on the East Pacific Rise (Halocypridina; Cladocopina)

Two new species of Ostracoda, Archiconchoecia (Archiconchoecia) chavturi (Halocypridina) and Polycopetta pax (Cladocopina), are described from two diffuse flow vent localities (Tica Site and Riftia Field Site) within Riftia pachyptila (Siboglinidae, Vestimentifera) aggregations on the East Pacific Rise, slightly north and west of 9°50' N, 104°17'W, depth 2500 m.

New thalassocypridine Ostracoda from anchialine caves of the Loyalty Islands, New Caledonia (Podocopida, Paracypridinae)

Four new species of Ostracoda belonging to the tribe Thalassocypridini are described from anchialine cave pools of the Loyalty Islands of New Caledonia: Dolerocypria iliffei n. sp., Paracypria uberis n. sp., Mungava woutersi n. sp., and Mungava xariessa n. sp. Detailed anatomical comparisons with 36 established species test the soundness of the emerging generic classification of thalassocypridines. Mangalocypria and Mungava are well-defined genera with exclusive, key diagnostic traits. Dolerocypria, Paracypria and Thalassocypria are somewhat less coherent. The essential qualities of Pontoparta and Parapontoparta remain elusive because of the heterogeneity of species referred to those nominal genera. Emended diagnoses are offered for the tribe Thalassocypridini and for the genera Dolerocypria, Paracypria, and Mungava.

Ostracoda from Johnston Atoll, Pacific Ocean, and Proposal of a New Tribe, Bruuniellini (Myodocopina: Cylindroleberididae)

Two new species of Ostracoda (Myodocopina), Parasterope pacifica Kornicker & Harrison-Nelson and Bruuniella beta Kornicker & Harrison-Nelson, from Johnston Atoll are described and illustrated. The ontogeny of the latter species is also described. In addition, the name Bruuniella alpha Kornicker & Harrison-Nelson is proposed for Bruuniella species A, previously described by Kornicker from the western Atlantic; a supplementary description of the species is provided. A new tribe, Bruuniellini, in the subfamily Cylindroleberidinae, family Cylindroleberididae, is proposed to include the genus Bruuniella, and keys are given to the two tribes in the subfamily and to the four known species of Bruuniella. The adult male of a species of the genus Bruuniella is described for the first time.

New species of Miocene cytheracean Ostracoda from the Pohang Basin, SE Korea

Abstract. Seven new species of ostracods are described from the Miocene deposits of the Pohang Basin in southeastern area, Korea. Baffinicythere paiki is only the ihird record of the genus Baffinicythere in the world. In this study, the following new species are erected: Callistocythere kyongjuensis, C. seojeongriensis, Baffinicythere paiki, Urocythereis pohangensis, Trachyleberis leei, T. praeniitsumai and Acanthocythereis koreana.

Novas ocorrências de fósseis nas formações Corumbataí e Estrada Nova do Estado de São Paulo e considerações preliminares sobre seus significados paleontológico e bioestratigráfico

O presente trabalho discute ocorrências e posicionamento estratigráfico dos fósseis das formações Corumbataí e Estrada Nova, incluindo espongiários (espículas), ostracodes, microvertebrados (dentes e escamas de paleoniscídeos), estromatólitos, oogônios de carófitas e bivalves que compõem as associações fossilíferas presentes nessas formações. A análise micropaleontológica permitiu: 1) classificar espículas de espongiários como oxeas monoxônidas características da Classe Demospôngia da Ordem Haplosclerida; 2) identificar dezesseis gêneros e vinte e três espécies novas de ostracodes, com base na morfologia externa da carapaça; 3) identificar dez morfotipos de ictiodontes e quatro tipos de escamas de paleoniscídeos; 4) descrever ocorrência de oogônios de carófitas, com os espécimes isolados, pela primeira vez, da rocha matriz. Considera-se a possibilidade das carófitas serem fósseis-índices do topo do Membro Teresina da Formação Estrada Nova, pois apresentam posição estratigráfica restrita e ampla distribuição geográfica. O estudo dos bivalves foi estendido para áreas pouco conhecidas, incluindo as regiões de Santa Cruz das Palmeiras, Tambaú, Porangaba, Angatuba, Guareí, Taguaí e Fartura para mostrar que o zoneamento bioestratigráfico proposto para a região de Rio Claro é válido também para outras áreas de São Paulo. As biozonas apresentam ampla distribuição geográfica como no caso da Zona Pinzonella neotropica-Jacquesia brasiliensis que vai do nordeste ao sudoeste do Estado. As características litológicas, petrográficas e estruturas sedimentares associadas às feições tafonômicas e paleoecológicas dos bioclastos mostraram que a maioria dos fósseis das formações Corumbataí e Estrada Nova não correspondem a deposições in situ, mas foram transportados e redepositados durante sucessivos eventos de tempestades.

New Ostracoda species from an Upper Cretaceous oyster reef, northern Gulf Coastal Plain, U.S.A.

This paper describes new species of Ostracoda from Late Cretaceous (late Santonian) oyster reefs of the Eutaw Formation of eastern Alabama. The reefs are composed almost exclusively ofOstrea cretaceaMorton, with rarer occurrences of the oystersExogyra upatoiensisStephenson andLopha ucheensis(Stephenson) and the bivalveAnomia preolmstediStephenson. Total thickness of the reefs is about 30 m, and the reefs are a major topographic feature across most of Macon and Russell Counties, Alabama, a distance of about 60 km. The reefs are interpreted to have been backbarrier sediments deposited under brackish conditions.Eight species of ostracodes are identified, including five new species described herein. The fauna is typically well preserved, and includes males, females, and juveniles. New species includeHaplocytheridea?eutawensis, Antibythocypris dimorphicus, A. nephotrema, Brachycythere asymmetrica, andEocytheropteron mutafoveata.Also discussed and illustrated areCytherella tuberculiferaAlexander,Haplocytheridea renfroensis renfroensisCrane, andFissocarinocythere gapensis(Alexander).

Middle Eocene Ostracoda from Baja California Sur, Mexico

Abstract. One genus and six new species of ostracodes are described from the Bateque Formation on the Pacific Coast of Baja California Sur, Mexico. Planktonic foraminifers indicate a mid Eocene age and the whole assemblage is characteristic of a shallow warm-water environment. Paijenborchella mezquitalensis sp. nov. is the second record of the genus Paijenborchella from the Eocene of North America. Except for this species and the new genus Bajacythere, the ostracode association has strong affinities with those described from the lower Tertiary Gulf Coast region.

Bairdia (Bairdia) perretae n.sp. nouvelle espèce d'Ostracode du Carbonifère inférieur des Pyrénées

A new species of Ostracodes, Bairdia (Bairdia) perretae n.sp., is dicovered and described in the Uppermost Visean - Lower Namurian of Western French Pyrénées. This species is a paleoecological index of deepest environments of outer platform.