''Melognathus'' is a

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of southeast Asian

tarantula Tarantulas comprise a group of large and often hairy spiders of the family Theraphosidae. , 1,040 species have been identified, with 156 genera. The term "tarantula" is usually used to describe members of the family Theraphosidae, although ...

s containing the single species, ''Melognathus dromeus''. It was erected in 1917 for a

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

collected from a ship that visited southeast Asia. In 1985, the species was moved to ''

Cyriopagopus ''Cyriopagopus'' is a genus of southeast Asian tarantulas found from Myanmar to the Philippines. , the genus includes species formerly placed in ''Haplopelma''. It was first described by Eugène Louis Simon in 1887. Description The species form ...

'' because the

autapomorphies In phylogenetics, an autapomorphy is a distinctive feature, known as a derived trait, that is unique to a given taxon. That is, it is found only in one taxon, but not found in any others or outgroup taxa, not even those most closely related to t ...

were not considered significant enough to warrant a new genus. Opinions between biologists were split, some using the original name and some using ''Cyriopagopus''. In a 2019 report, Gabriel and Sherwood pointed out that in addition to the differences in

pedipalp Pedipalps (commonly shortened to palps or palpi) are the second pair of appendages of chelicerates – a group of arthropods including spiders, scorpions, horseshoe crabs, and sea spiders. The pedipalps are lateral to the chelicerae ("jaws") and ...

morphology, the holotype exhibits leg features that indicate an

arboreal Arboreal locomotion is the Animal locomotion, locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. Th ...

species, while species of ''Cyriopagopus'' are largely terrestrial. The ambiguous location of the holotype has left room for speculation, but the World Spider Catalog accepts this genus.

See also

References

Further reading