Taxonomy, Volume 1, Issue 2 (June 2021) – 8 articles

Trichomycterus has been considered for a long time to be the most problematic genus of the diverse neotropical subfamily Trichomycterinae. Recently, Trichomycterus was restricted to a clade from eastern South America supported by molecular data, but no unique morphological character state was found to distinguish it, making it difficult to allocate new species based on morphology alone. The objectives of this study were to conduct an osteological comparative analysis comprising a large sample of valid species of Trichomycterus, to conduct a total evidence phylogenetic analysis, combining osteological characters and a multigene database, and to propose an intrageneric classification based on the results of the phylogenetic analysis. Fifty-two osteological characters were combined with a multigene molecular data set of 2974 bp for 44 species of Trichomycterus, and 21 outgroups generated a well-supported phylogenetic tree, making it possible to delimit and diagnose intrageneric lineages, of which six subgenera are recognized. The high morphological diversity of osteological structures herein first reported for Trichomycterus from eastern South America is possibly related to some ecological specializations. This study shows that osteological characters combined with molecular data may be useful to consistently delimit and distinguish between trichomycterines, shedding light on the still persistent problems in trichomycterine systematics. Full article

Conspecificity of the morphologically-similar, sympatric nudibranch species Dendrodoris gunnamatta (Allen, 1932) and Dendrodoris krusensternii (Gray, 1850) was tested using sequences of the mitochondrial COI gene. Data analysis supports the presence of phenotypic polymorphy in D. krusensternii where specimens from large estuaries and embayments in central New South Wales, Australia either lack or have highly reduced sky-blue ocellae. Full article

A new Galeommatid bivalve is described for the Mediterranean Sea, tentatively assigned to the elusive genus Draculamya Oliver and Lützen, 2011. “Draculamya” uraniae n. sp is described upon a number of dead but fresh and articulated specimens, plus many loose valves. Its distribution is almost basin-wide in the Mediterranean, and it possibly occurs in the adjacent Gulf of Cadiz. As for many members in Galeommatida, we hypothesize that “Draculamya” uraniae lives as commensal upon a still-unknown host. The possible co-identity of the extant genus Draculamya with the morphologically similar Pliocene Glibertia Van der Meulen, 1951, is discussed, although the lack of anatomical and genetic support leaves the problem open. Full article

Two new mite species belonging to the genus Stereotydeus Berlese, 1901 were discovered from locations along the coast of Victoria Land, continental Antarctica. Previous records of this genus in the area under study only reported the presence of S. belli and S. mollis. Although those studies included no morphological analyses, it has since been assumed that only these species were present within the area. Specimens of S. ineffabilis sp. nov. and S. nunatakis sp. nov. were obtained, sometimes in sympatry, from four different localities in Central and South Victoria Land and are here described and illustrated using optical and scanning electron microscopy (SEM) techniques. Features useful for identification of the two new Stereotydeus species include the size of the specimens, the length of the apical segment of pedipalps, the presence/absence of division of the femora, the position of solenidia, the shape and disposition of the rhagidiform organs on the tarsi, the shape of the apical setae of the tarsi, the numbers of aggenital setae and the position of the anal opening. A key to 14 of the 15 currently described Antarctic and sub-Antarctic Stereotydeus species is provided. Full article

In this article, I revise the taxonomy of the species and subspecies of the genus Phrynosoma through phylogenetic and species delimitation approaches based on four mtDNA markers (ND1, ND2, ND4, and 12S). The resulting taxonomy recognizes 12 species (P. asio, P. bracconieri, P. cornutum, P. coronatum, P. douglasii, P. hernandesi, P. mcallii, P. modestum, P. orbiculare, P. platyrhinos, P. solare, and P. taurus). Several of these species are divided into subspecies as follows: P. coronatum (P. c. coronatum, P. c. blainvillii, P. c. cerroense, and P. c. frontale), P. cornutum (P. c. cornutum and P. c. bufonium), P. hernandesi (P. h. hernandesi, P. h. ditmarsi, and P. h. ornatum), P. orbiculare (P. o. orbiculare, P. o. bradti, P. o. boucardii, P. o. cortezii, P. o. dugesii, and P. o. durangoensis), P. platyrhinos (P. p. platyrhinos and P. p. goodei), P. taurus (P. t. taurus and P. t. sherbrookei). In this coherent and objective approach, those taxa treated here as subspecies have diverged to a much lesser degree than those that are herein recognized as separate species. Typically, those taxa recognized as subspecies are one another’s closest relatives (i.e., they together form a monophyletic group that represents the species) and are distributed allopatrically. In this approach, all separate evolutionarily significant units are recognized as named taxa—either species or subspecies—thereby reflecting the importance of identifying and naming such units for conservation. I provide a checklist of the recognized species and subspecies of Phrynosoma along with synonymies and distribution maps. Full article

Although bryozoans are a diverse phylum of aquatic invertebrates with a rich fossil record, very little has been written about bryozoan faunas from the latest Pleistocene at a time of rapid global change when temperatures increased dramatically and the sea-level rose. Two species of cyclostome and eight species of cheilostome bryozoans are here described from the late Devensian Clyde Clay Formation of Greenock, Scotland, based on historical material in the collections of the NHM, UK. All are illustrated for the first time from this deposit using scanning electron microscopy. Three of the species (Tubulipora cf. marisalbi, Rhamphostomella radiatula and Schizomavella porifera) are unknown from the seas around Scotland at the present-day but occur in colder waters to the north. This is consistent with the poleward retreat of cold-water species as seawater temperatures increased at the end of the Pleistocene. Full article

A total of 14 species in seven tingid genera have been described from the mid-Cretaceous Burmese (Kachin) amber from northern Myanmar, with very distinct paleofauna. Here, a new species of a new genus, Burmavianaida anomalocapitata gen. et sp. nov., is described from Kachin amber. This new species can be readily distinguished from the other described tingid taxa by the apparently smaller body and the structures of the pronotum and hemelytron. Burmavianaida gen. nov. shares the diagnostic characters with two clades composed of three extant subfamilies (Cantacaderinae + Tinginae) and Vianaidinae and may represent an extinct clade distinct from them. To the best of our knowledge, B. anomalocapitata sp. nov. is the smallest species of Tingidae among over 2600 described species. Our new finding supports the hypothesis of the miniaturization phenomenon of insects in Kachin amber, as suggested by previous studies. Full article

A recent taxonomic revision split the circumglobal sea hare Aplysia parvula into 10 constituent taxa, of which only three are likely to be found in the Southern Pacific. This prompted an investigation of animals previously identified as A. parvula from Australia. Specimens collected from Eastern Australia and Hunter Island, east of New Caledonia, could not be satisfactorily identified with any of the currently accepted taxa based on morphological diagnostic features listed in the revision; however, the presence of a highly concave shell is diagnostic. Quantification of genetic divergence using Cytochrome Oxidase I (COI) supports the delineation of this species as a distinct taxon, and a phylogenetic reconstruction based on concatenated COI, 16S and H3 markers reveals a sister relationship with the newly described Aplysia ghanimii from the Atlantic and Western Indian Oceans and an undescribed species from Japan. As a result, the name Aplysia concava G. B. Sowerby, I, 1833 is resurrected for this species. As the original description was based solely on a shell, a redescription is provided here with photographs of living animals and microscope images of internal anatomical structures. Full article