Family HEXATHELIDAE Simon, 1892
Compiler and date details
Robert J. Raven, Queensland Museum, PO Box 3300, South Brisbane, Queensland 4101
Introduction
The Hexathelidae include spiders of the genus Atrax (Funnelwebs) that have the most toxic venom recorded for any spider. Fourteen deaths have been recorded from their bites; no deaths, however, have been recorded since the introduction of antivenom effective in bites of all species of Atrax and Hadronyche. These spiders are found only in eastern Australia, including Tasmania, and around Adelaide in South Australia. The family also includes the only Australian mygalomorphs that retain six spinnerets (Hexathelinae) and the Tasmanian relict, Plesiothele fentoni, which has the most plesiomorphic spinneret condition known in extant mygalomorphs. The Queensland species, Bymainiella terraereginae, has the most plesiomorphic excretory system of any known chelicerate with three pairs of coxal gland outlets on coxae I, II, IV.
Diagnosis
Differ from Mecicobothriidae in the absence of dorsal abdominal sclerites, the numerous labial and maxillary cuspules, and/or the transverse or pitlike fovea, and from Dipluridae in the arched caput and glabrous carapace.
Mygalomorph spiders with numerous cuspules usually present on labium and maxillae. Serrula present. Three claws; one row of teeth on paired claws; third claw short, curved with few fine teeth. Scopulae absent in males and females. Dorsal abdominal sclerite and third haematodocha of male palp absent. Cymbium similarly bilobed. Apical segment of the posterior lateral spinnerets digitiform or longer. Carapace glabrous with broad pit-like or transverse fovea. Caput arched. Few, if any spines, on anterior tarsi. Rastellum absent.
Diagnosis References
Raven, R.J. 1985. The spider infraorder Mygalomorphae (Araneae): Cladistics and Systematics. Bulletin of the American Museum of Natural History 182(1): 1-180 [Date published December 5, 1985] [70]