Dipluridae

The family Dipluridae, commonly referred to as curtain-web spiders, represents a distinct group within the infraorder Mygalomorphae. These spiders are characterized by possessing two pairs of booklungs and chelicerae, or fangs, that exhibit a stabbing motion. Historically, this family included genera now classified elsewhere, such as those belonging to the Sydney funnel-web spider, which are now in the family Atracidae.

Description and Biology

A notable physical trait of Dipluridae spiders is the absence of rastella on their chelicerae. Morphologically, their carapace features a head region that is not elevated above the thoracic region. Their spinnerets, organs responsible for silk extrusion, are also distinctive: the posterior median spinnerets are considerably shorter than the elongated, three-segmented posterior lateral spinnerets, which can be nearly as long as the spider's opisthosoma. Most species within this family are of medium to small size, with some individuals reaching approximately 15 mm in body length. Interestingly, some cave-dwelling species, like Masteria caeca, have evolved to be eyeless.

In terms of their living habits, Dipluridae spiders are known for constructing rather untidy funnel-webs. Some genera, such as Diplura, Trechona, Harpathele, and certain Linothele species, opt to build silk-lined burrows instead of webs. These retreats are typically established in sheltered locations, including crevices in earthen banks, beneath the bark of trees, under fallen logs, or within accumulations of leaf litter.

Distribution and Taxonomy

The geographic distribution of the Dipluridae family is primarily concentrated in South America and the Caribbean. However, certain species belonging to the genus Masteria have also been documented in Australia and Oceania. The family was first formally established in 1889 by Eugène Simon. Subsequent detailed studies, particularly by Robert Raven in 1985, characterized Dipluridae based on morphological features, especially their long and widely spaced spinnerets. Raven's initial classification divided the family into four subfamilies. However, later molecular phylogenetic research indicated that this circumscription was not monophyletic. Consequently, in 2020, the family was redefined to include only the subfamilies Diplurinae and Masteriinae, with other former subfamilies elevated to their own families. Dipluridae is considered most closely related to the family Cyrtaucheniidae and belongs to the 'Nemesioidina' clade of advanced mygalomorph families.