Neofunctionalization of duplicated gene copies is thought to be an important process underlying the origin of evolutionary novelty and provides an elegant mechanism for the origin of new phenotypic traits. One putative case where a new gene copy has been linked to a novel morphological trait is the origin of the arachnid patella, a taxonomically restricted leg segment. In spiders, the origin of this segment has been linked to the origin of the paralog dachshund-2, suggesting that a new gene facilitated the expression of a new trait.
View Article and Find Full Text PDFBurmese amber preserves a diverse assemblage of Cretaceous arachnids, and among pseudoscorpions (Arachnida: Pseudoscorpiones), ten species in five families have already been named. Here, we describe a new fossil species from Burmese amber in the pseudoscorpion family Hyidae, providing detailed measurements, photographs and 3D-models from synchrotron scanning. Based on morphology, the new fossil, sp.
View Article and Find Full Text PDFNeofunctionalization of duplicated gene copies is thought to be an important process underlying the origin of evolutionary novelty and provides an elegant mechanism for the origin of new phenotypic traits. One putative case where a new gene copy has been linked to a novel morphological trait is the origin of the arachnid patella, a taxonomically restricted leg segment. In spiders, the origin of this segment has been linked to the origin of the paralog , suggesting that a new gene facilitated the expression of a new trait.
View Article and Find Full Text PDFA new species of is described from dry habitats in a cave in central Colorado. Like other cave-dwelling species of , the new species , shows relatively modest morphological adaptations, such as pale colouration and slightly elongated appendages, compared with their epigean counterparts. This species is the sixth cave-dwelling species of described from North America and, like other cave-dwelling in North America and Europe, tends to be distributed in more southerly regions.
View Article and Find Full Text PDFAnimal genitalia are thought to evolve rapidly and divergently in response to sexual selection. Studies of genital evolution have focused largely on male genitalia. The paucity of work on female genital morphology is probably due to problems faced in quantifying shape variation, due to their composition and accessibility.
View Article and Find Full Text PDFThe pseudoscorpion genus Indohya Beier, 1974 is known to occur in three Gondwanan fragments around the Indian Oceansouthern India, Madagascar and north-western Australiasuggesting that the genus had evolved prior to the breakup of Gondwana and was present on each landmass as they rifted apart during the Mesozoic. The Australian fauna is the most diverse, with nine species previously described from Cape Range and the Kimberley region of north-western Australia. The present study documents the genus Indohya in Australia using a combination of morphology and DNA sequence data.
View Article and Find Full Text PDFThe pseudoscorpion family Withiidae is widely distributed around the world, with most of its diversity in tropical areas. Five new species and a new genus from Colombia are described: , , , and the genus with two species and A reassessment of the subgenus Dolichowithius (Oligowithius) Beier, 1936 allows the elevation to a full generic level, and the transfer of the only known species to , forming the new combination (Beier, 1936),
View Article and Find Full Text PDFDuring the Paleogene, the Holarctic experienced drastic climatic oscillations, including periods of extensive glaciation. These changes had a severe impact on both the flora and fauna causing widespread extinction and range shifts with some taxa retreating to refugia in the Mediterranean Basin. Here we provide evidence for this hypothesis using fossils from the pseudoscorpion family Garypinidae Daday, 1889 (Arachnida: Pseudoscorpiones).
View Article and Find Full Text PDFModern advances in DNA sequencing hold the promise of facilitating descriptions of new organisms at ever finer precision but have come with challenges as the major Codes of bionomenclature contain poorly defined requirements for species and subspecies diagnoses (henceforth, species diagnoses), which is particularly problematic for DNA-based taxonomy. We, the commissioners of the International Commission on Zoological Nomenclature, advocate a tightening of the definition of "species diagnosis" in future editions of Codes of bionomenclature, for example, through the introduction of requirements for specific information on the character states of differentiating traits in comparison with similar species. Such new provisions would enhance taxonomic standards and ensure that all diagnoses, including DNA-based ones, contain adequate taxonomic context.
View Article and Find Full Text PDFPreviously described from only fragments of exoskeleton and juvenile specimens, the cave spider genus (Araneae: Anamidae), endemic to the Nullarbor Plain, is the only troglomorphic member of the infraorder Mygalomorphae recorded from Australia. We investigated the distribution of in South Australia, collecting and observing the first (intact) mature specimens, widening the number of caves it has been recorded in, and documenting threats to conservation. Phylogenetic analyses support the placement of as an independent lineage within the subfamily Anaminae (the ' group') and provide unequivocal evidence that populations from apparently isolated cave systems are conspecifics of Harvey & Rix, 2020, with extremely low or negligible inter-population mitochondrial divergences.
View Article and Find Full Text PDFUnderstanding the drivers of morphological convergence requires investigation into its relationship with behavior and niche space, and such investigations in turn provide insights into evolutionary dynamics, functional morphology, and life history. Mygalomorph spiders (trapdoor spiders and their kin) have long been associated with high levels of morphological homoplasy, and many convergent features can be intuitively associated with different behavioral niches. Using genus-level phylogenies based on recent genomic studies and a newly assembled matrix of discrete behavioral and somatic morphological characters, we reconstruct the evolution of burrowing behavior in the Mygalomorphae, compare the influence of behavior and evolutionary history on somatic morphology, and test hypotheses of correlated evolution between specific morphological features and behavior.
View Article and Find Full Text PDFAcariform mites are an ancient and megadiverse lineage that may have experienced a complex pattern of invasions into terrestrial and aquatic habitats. These among-realm transitions may relate to periods of turmoil in Earth's history or be simply results of uneven biodiversity patterns across habitats. Here, we inferred a dated, representative acariform phylogeny (five genes, 9,200 bp aligned, 367 terminals belonging to 150 ingroup plus 15 outgroup families, 23 fossil calibration points) which was used to infer transitions between marine/freshwater/terrestrial habitats.
View Article and Find Full Text PDFThe pseudoscorpion genus Rhopalochernes Beier, 1932 is restricted to the Neotropical region and currently includes eight species. Recent field collections in the Caribbean region of Colombia have revealed the presence of two previously undescribed species, which are here described as Rhopalochernes luiscarlosi sp. nov.
View Article and Find Full Text PDFScorpions constitute a charismatic lineage of arthropods and comprise more than 2500 described species. Found throughout various tropical and temperate habitats, these predatory arachnids have a long evolutionary history, with a fossil record that began in the Silurian. While all scorpions are venomous, the asymmetrically diverse family Buthidae harbors nearly half the diversity of extant scorpions, and all but one of the 58 species that are medically significant to humans.
View Article and Find Full Text PDFDeciphering the evolutionary relationships of Chelicerata (arachnids, horseshoe crabs, and allied taxa) has proven notoriously difficult, due to their ancient rapid radiation and the incidence of elevated evolutionary rates in several lineages. Although conflicting hypotheses prevail in morphological and molecular data sets alike, the monophyly of Arachnida is nearly universally accepted, despite historical lack of support in molecular data sets. Some phylotranscriptomic analyses have recovered arachnid monophyly, but these did not sample all living orders, whereas analyses including all orders have failed to recover Arachnida.
View Article and Find Full Text PDFThe name "millipede" translates to a thousand feet (from mille "thousand" and pes "foot"). However, no millipede has ever been described with more than 750 legs. We discovered a new record-setting species of millipede with 1,306 legs, Eumillipes persephone, from Western Australia.
View Article and Find Full Text PDFAustralia is in the midst of an extinction crisis, having already lost 10% of terrestrial mammal fauna since European settlement and with hundreds of other species at high risk of extinction. The decline of the nation's biota is a result of an array of threatening processes; however, a comprehensive taxon-specific understanding of threats and their relative impacts remains undocumented nationally. Using expert consultation, we compile the first complete, validated, and consistent taxon-specific threat and impact dataset for all nationally listed threatened taxa in Australia.
View Article and Find Full Text PDFThe assembly of the Australian arid zone biota has long fascinated biogeographers. Covering over two-thirds of the continent, Australia's vast arid zone biome is home to a distinctive fauna and flora, including numerous lineages which have diversified since the Eocene. Tracing the origins and speciation history of these arid zone taxa has been an ongoing endeavour since the advent of molecular phylogenetics, and an increasing number of studies on invertebrate animals are beginning to complement a rich history of research on vertebrate and plant taxa.
View Article and Find Full Text PDFLong-branch attraction is a systematic artifact that results in erroneous groupings of fast-evolving taxa. The combination of short, deep internodes in tandem with long-branch attraction artifacts has produced empirically intractable parts of the Tree of Life. One such group is the arthropod subphylum Chelicerata, whose backbone phylogeny has remained unstable despite improvements in phylogenetic methods and genome-scale data sets.
View Article and Find Full Text PDFThe schizomid fauna of mainland Australia currently comprises 60 species within seven named genera, of which five are endemic to the continent: Attenuizomus Harvey, 2000, Brignolizomus Harvey, 2000, Draculoides Harvey, 1992, Julattenius Harvey, 1992, Notozomus Harvey, 2000. Most Australian schizomids have been described from eastern and northern Australia, but there is also a significant subterranean fauna that has been found in hypogean habitats in the semi-arid Pilbara region of Western Australia. The vast majority of these species can be assigned to the genus Draculoides and this study is the first in a proposed series to revise this highly diverse genus.
View Article and Find Full Text PDFThe D'Aguilar Range of subtropical south-eastern Queensland (Australia), harbours an upland rainforest biota characterised by high levels of endemic diversity. Following recent phylogenetic and biogeographic research into the open-holed trapdoor spiders of the genus Namea Raven, 1984 (family Anamidae), remarkable levels of sympatry for a single genus of mygalomorph spiders were recorded from the D'Aguilar Range. It is now known that eight different species in the genus can be found in the D'Aguilar uplands, with five apparently endemic to rainforest habitats.
View Article and Find Full Text PDFThe species of the millipede genus Antichiropus Attems, 1911 found in the Pilbara region of Western Australia are reviewed, and 33 new species are described. The new species are: A. anguinus Car, n.
View Article and Find Full Text PDFThe open-holed trapdoor spiders of the genus Teyl Main, 1975 from the Pilbara bioregion of Western Australia are investigated. A single endemic species from the southern Pilbara, T. heuretes sp.
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