18-427: Hexathelidae is a family of mygalomorph spiders. It is one of a number of families and genera of spiders known as tunnelweb or funnel-web spiders . In 2018, the family was substantially reduced in size by genera being moved to three separate families: Atracidae , Macrothelidae and Porrhothelidae . These spiders are medium to large in size, with body lengths ranging from 1 to 5 cm (0.5 to 2 in). The body
36-537: A cladogram showing family relationships was published in 2005, with two significant studies in 2018. The division of Mygalomorphae into two superfamilies, Atypoidea and Avicularioidea , has been established in many studies. The Atypoidea retain some vestiges of abdominal segmentation in the form of dorsal tergites ; the Avicularioidea lack these. Molecular phylogenetic studies undertaken between 2012 and 2017 have found somewhat different relationships within
54-587: A giant mygalomorph from the Upper Carboniferous (about 350 million years ago), but was later found to be a eurypterid . The oldest known mygalomorph is Rosamygale grauvogeli , an avicularoid from the Triassic of northeastern France. No mygalomorphs from the Jurassic have yet been found. The number of families and their relationships have both been undergoing substantial changes since
72-451: A metre in diameter. Unlike Araneomorphae , which die after about a year, Mygalomorphae can live for up to 25 years, and some do not reach maturity until they are about six years old. Some flies in the family Acroceridae that are endoparasites of mygalomorphs may remain dormant in their book lungs for as long as 10 years before beginning their development and consuming the spider. One female trapdoor spider, first recorded in
90-716: A new subfamily, Australothelinae, was generated and placed in the family Euagridae. The preferred cladogram from Optova et al. (2020) is: Hexurellidae Mecicobothriidae Atypidae Megahexuridae Antrodiaetidae Ischnothelidae Microhexuridae Hexathelidae Euagridae Porrhothelidae Macrothelidae Paratropididae Stasimopidae Atracidae Actinopodidae Halonoproctidae Migidae Idiopidae Ctenizidae Euctenizidae Bemmeridae Barychelidae Theraphosidae Nemesiidae Pycnothelidae Dipluridae Cyrtaucheniidae Anamidae Entypesidae Microstigmatidae In 1802, C. A. Walckenaer separated mygalomorph spiders into
108-767: A separate genus , Mygale , leaving all other spiders in Aranea In 1985, Robert Raven published a monograph of the Mygalomorphae in which he proposed an internal classification for the Mygalomorphae, based on morphological features. Opatova et al . (2020) commented "In short, much of today's classification scheme dates back to Raven (1985)". Raven used various compound ranks, such as "gigapicoorder" and "hyperpicoorder". Ignoring these unusual rank names, his classification can be shown diagrammatically: Mecicobothriidae Microstigmatidae Hexathelidae Trapdoor spider Too Many Requests If you report this error to
126-528: A survey in 1974 in Western Australia, is known to have lived for 43 years. The name is derived from the Greek mygalē , meaning "shrew", plus morphē meaning form or shape. An older name for the group is Orthognatha , derived from the orientation of the fangs which point straight down and do not cross each other (as they do in the araneomorphs ). Megarachne servinei was thought to be
144-928: Is common. These spiders construct a funnel -shaped web and lurk for prey in the small end of the funnel. They frequently search for a place to nest under human dwellings, or under nearby rocks, logs, or other similar objects. They are most active at night . Some build in rain forests, both in the soil and in hollows on trees; others build entirely in sand, e.g., Fraser Island, southeastern Queensland. In Australia, these spiders tend to prefer cooler climates, hence they are found primarily in rain forests. Mygalomorphae The Mygalomorphae , or mygalomorphs , are an infraorder of spiders , and comprise one of three major groups of living spiders with over 3,000 species, found on all continents except Antarctica. Many members are known as trapdoor spiders due to their creation of trapdoors over their burrows. Other prominent groups include Australian funnel web spiders and tarantulas , with
162-525: Is typically three times longer than it is wide. They are darkly colored, ranging from black to brown, with a glossy carapace covering the front part of the body. Like the related diplurid spiders, the hexathelids have generally long spinnerets . Their moderately long posterior spinnerets and other features make the Hexathelidae appear similar to the Dipluridae , and were considered a subfamily of
180-621: The World Spider Catalog accepts the following genera: As of May 2018, some genera formerly placed in Hexathelidae have been moved to other families: Five of the seven genera are found in Australia and New Zealand . Two genera are from Argentina and Chile in South America. Hexathelids typically live in burrows, which are constructed in the ground or in tree hollows. An elaborately constructed burrow entrance
198-761: The Avicularioidea. Some families appear not to be monophyletic and further changes are possible in the future. Rosamygale belongs to Avicularioidea, based on the absence of an abdominal scutum and well-separated posterior lateral spinnerets. Mygalomorphae tend to be highly morphologically conserved, which makes it difficult to find reliable morphological features to use for taxonomy. It has been hypothesized that because Mygalomorphae all tend to be fossorial and live in tubular webs, they are subjected to similar selective pressures, so most species should evolve in similar ways. Additionally, this may also mean that homoplasies are more likely to occur, further complicating taxonomy based on morphology. The relationships of taxa in
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#1732783335061216-427: The Mygalomorphae were restructured based on a comprehensive phylogenetic study by Opatova et al . (2020) The generic composition of the families Ctenizidae, Cyrtaucheniidae, Dipluridae, and Nemesiidae were relimited. Five subfamilies were raised to the rank of family: Anamidae, Euagridae, Ischnothelidae, Pycnothelidae, and Bemmeridae. Three new families were created: Entypesidae, Microhexuridae, and Stasimopidae. Lastly,
234-506: The exception of the Australian funnel-web spiders , especially those of the genus Atrax . While the world's biggest spiders are mygalomorphs – Theraphosa blondi has a body length of 10 cm (3.9 in) and a leg span of 28 cm (11 in) – some species are less than one millimeter (0.039 in) long. Mygalomorphs are capable of spinning at least slightly adhesive silk, and some build elaborate capture webs that approach
252-861: The external abdominal segmentation of ancestral arachnids and have at least vestiges of four pairs of spinnerets, whereas mygalomorphs lack abdominal segmentation (like other opistotheles) and have a reduced number of spinnerets, often only two pairs. Like spiders in general, most species of Mygalomorphae have eight eyes, one pair of principal and three pairs of secondary eyes. Their chelicerae and fangs are large and powerful and have ample venom glands that lie entirely within their chelicerae . These weapons, combined with their size and strength, make Mygalomorph spiders powerful predators. Many of these spiders are well adapted to killing other large arthropods and will also sometimes kill small mammals , birds , and reptiles . Despite their fearsome appearance and reputation, most mygalomorph spiders are not harmful to humans, with
270-430: The latter accounting for around one third of all mygalomorphs. This group of spiders comprises mostly heavy-bodied, stout-legged spiders including tarantulas , Australian funnel-web spiders , mouse spiders , and various families of spiders commonly called trapdoor spiders . Like the " primitive " suborder of spiders Mesothelae , they have two pairs of book lungs , and downward-pointing chelicerae . Because of this,
288-537: The latter until 1980. Like other Mygalomorphae (also called the Orthognatha, an infraorder of spiders which includes the true tarantulas ), these spiders have fangs which point straight down and do not cross each other (see also Araneomorphae ). They have ample venom glands that lie entirely within their chelicerae . Their chelicerae and fangs are large and powerful. A molecular phylogenetic study in 2018 showed that Hexathelidae, as then circumscribed ,
306-448: The two groups were once believed to be closely related. Later it was realised that the common ancestors of all spiders had these features (a state known as symplesiomorphy ). Following the branching into the suborders of Mesothelae and Opisthothelae , the mygalomorphs retained them, while their fellow Opisthothelae members, the araneomorphs , evolved new "modern" features, including a cribellum and cross-acting fangs. Mesotheles retain
324-442: Was not monophyletic and hence split off genera into the new families Atracidae , Macrothelidae and Porrhothelidae . The following cladogram shows the relationships found between these families (former Hexathelidae families marked with boxes). Dipluridae Hexathelidae Porrhothelidae Macrothelidae Atracidae Actinopodidae Calisoga (Nemesiidae) Hebestatis (Halonoproctidae) As of April 2019,
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