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  • Author or Editor: Beatriz A. Dorda x
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Abstract

The “Iberobathynella group”, or Iberobathynellini tribe, is a complex of six genera consisting of 33 nominal species and several cryptic species with an amphiatlantic distribution (in Europe, North Africa and North America). A modern systematic revision of this group of subterranean crustaceans is presented here. A phylogenetic and biogeographic study using morphological and molecular data (mitocondrial coi and nuclear 18S) was carried out and allowed to a) re-evaluate the taxonomic status and validity of previously erected subtribes, genera and subgenera that show congruence in the data; b) assess whether the identified mitochondrial lineages represent cryptic species; c) provide a plausible phylogenetic hypothesis for the relationships within Iberobathynellini and with the other two genera of the family Parabathynellidae that inhabit North America and Europe (Montanabathynella and Parabathynella, respectively); d) propose a plausible temporal and historical framework (paleobiogeographic scenario) for the diversification and evolution of the Iberobathynellini tribe based on the current distribution of morphotypes and their estimated times of divergence. Our results show that in parabathynellids, molecular and morphological divergences are not always congruent. Subtribe and subgenus are invalid categories so they must be eliminated. Paraiberobathynella genus needs to be revisited. The molecular dating results support the early divergence of the Iberobathynellini Tribe (Upper Cretaceous, around 78 Mya) and the vicariance by plate tectonics as main factor to explain the amphi-Atlantic distribution shown by this ancient subterranean crustacean group. Since there are species morphologically very similar to I. magna and I. imuniensis, but genetically different, we can ensure the existence of at least three cryptic species. Texanobathynella is undoubtedly a valid genus distinct from Iberobathynella. Montanabathynella and Parabathynella are two well-differentiated genera closely related to the Iberobathynellini tribe.

Open Access
In: Contributions to Zoology

Molecular data for the mt 16S rDNA gene fragment of a bathynellacean is here presented for the first time and used to analyze the relationship of the group within the crustacean class Malacostraca (Arthropoda, Bathynellacea). Two contrasting views have classified the bathynelids as being either within the order Syncarida or in a separate super-order Podophallocarida belonging to the infra-class Eonomostraca, a disagreement based mainly on debates over external and internal morphology. The preliminary analyses offered here in question the placement of this Bathynellacea within the Syncarida, and suggest the need for a further study of relationships among the malacostracan groups.

Open Access
In: Contributions to Zoology

A preliminary molecular phylogenetic framework for 12 genera (23 species) of the family Parabathynellidae from Europe, Australia, North Africa and India is presented based on mitochondrial and nuclear markers (Cox1 and 18S). The generated hypothesis places the Southeast Asia genus Paraeobathynella closer to European genera (Iberobathynella, Paraiberobathynella and Parabathynella) than to the Australian (Brevisomabathynella, Atopobathynella, Billibathynella, Octobathynella, Arkaroolabathynella and Lockyerenella) or Indian genera (Habrobathynella), or to the cosmopolitan genus Hexabathynella (Spain and Australia). Three new species of the genus Paraeobathynella from Thailand, P. ratensis n. sp., P. siamensis n. sp. and P. hanjavanitiana n. sp., are described based on morphological and molecular features. This is the first record of the genus from Thailand and extends its range of distribution within Asia, where it was previously known only from Vietnam. The new species are clearly separated as independent units at least since the Middle Miocene.

Open Access
In: Contributions to Zoology