The Haplogynae or haplogynes are one of the two main groups into which

araneomorph The Araneomorphae (also called the Labidognatha) are an infraorder of spiders. They are distinguishable by chelicerae (fangs) that point diagonally forward and cross in a pinching action, in contrast to the Mygalomorphae (tarantulas and their cl ...

spider Spiders ( order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species ...

s have traditionally been divided, the other being the

Entelegynae The Entelegynae or entelegynes are a subgroup of araneomorph spiders, the largest of the two main groups into which the araneomorphs were traditionally divided. Females have a genital plate ( epigynum) and a "flow through" fertilization system; m ...

. Morphological phylogenetic studies suggested that the Haplogynae formed a

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

; more recent molecular phylogenetic studies refute this, although many of the

ecribellate Cribellum literally means "little sieve", and in biology the term generally applies to anatomical structures in the form of tiny perforated plates. In certain groups of diatoms it refers to microscopically punctured regions of the frustule, or o ...

haplogynes do appear to form a clade, Synspermiata. Unlike the

, haplogynes lack hardened (sclerotized) female genitalia (

epigyne The epigyne or epigynum is the external genital structure of female spiders. As the epigyne varies greatly in form in different species, even in closely related ones, it often provides the most distinctive characteristic for recognizing species. ...

s). Most of the species within this group have six eyes, as opposed to most other spiders. Spiders in the genus '' Tetrablemma'' (

Tetrablemmidae Tetrablemmidae, sometimes called armored spiders, is a family of tropical araneomorph spiders first described by Octavius Pickard-Cambridge in 1873. It contains 126 described species in 29 genera from southeast Asia, with a few that occur in Afric ...

) have only four eyes, as do some members of the family Caponiidae; caponiids may even have only two eyes. However, spiders in the family

Plectreuridae Plectreuridae, also called plectreurid spiders, is a small spider family confined to the Southwestern United States, Mexico, and the Caribbean. Only two living genera are known—the nominate genus '' Plectreurys'' and '' Kibramoa''. In the pa ...

have the normal eight eyes.

Phylogeny

The Haplogynae are one of the two major groups into which araneomorph spiders were traditionally divided, the other being the Entelegynae. In 2005, Coddington summarized the relationships of these groups as suggested by morphological phylogenetic studies: Subsequent molecular phylogenetic studies have confirmed the

monophyly In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic grou ...

of some of the groups suggested by morphological studies, while rejecting many others. A study published in 2015 suggested that two families formerly placed in the Haplogynae do not belong there. Filistatidae groups with

Hypochilidae Lampshade spiders, family Hypochilidae, are among the most primitive of araneomorph spiders. There are two genera and twelve species currently recognized. Like mygalomorphs, most hypochilids have two pairs of book lungs, but like araneomorphs th ...

at the base of the Haplogynae;

Leptonetidae Leptonetidae is a relatively primitive family of spiders first described by Eugène Simon in 1890. It is made up of tiny haplogyne spiders, meaning they lack the hardened external female genitalia. Their six eyes are arranged in a semicircle of f ...

is basal to the Entelegynae. The similarity of some morphological features of Leptonetidae to those of entelegynes had already been noted. In 2016, a large molecular phylogenetic study was published online that included 932 spider species, representing all but one of the then known families. It "refutes important higher-level groups", including Paleocribellatae, Neocribellatae, Araneoclada and Haplogynae. In the preferred cladogram, the "Haplogynae" are divided among a number of clades basal to the Entelegynae, forming at most a grade. "Haplogynae" in the sense of Coddington (2005) are shaded yellow in the cladogram below; Entelegynae in the same sense are shaded blue. The clade Synspermiata comprises all the ecribellate haplogynes and is consistently recovered, but with low support.

Families

As shown above, Filistatidae and

are placed outside the traditional haplogynes in the analysis by Wheeler et al. (2017). Traditional haplogyne families they place in Synspermiata are: * Caponiidae *

Diguetidae Coneweb spiders (Diguetidae) are six-eyed haplogyne spiders that live in tangled space webs, fashioning a cone-like central retreat where they hide and lay eggs. It is a small family, containing only two genera with fifteen species and is con ...

Drymusidae Drymusidae is a family of araneomorph spiders first described by Eugène Simon in 1893, and elevated to family status by Pekka T. Lehtinen in 1986. Genera , the World Spider Catalog accepts the following genera: *''Drymusa ''Drymusa'' is a ...

Dysderidae Dysderidae, also known as woodlouse hunters, sowbug-eating spiders, and cell spiders, is a family of araneomorph spiders first described by Carl Ludwig Koch in 1837. They are found primarily in Eurasia, extending into North Africa with very few s ...

Ochyroceratidae Ochyroceratidae is a six-eyed spider family, with 165 described species in ten genera. They are common inhabitants of caves and the tropical forest litter of South Africa, the Caribbean, Asia and South America. Considered an ecological counterpar ...

Oonopidae Oonopidae, also known as goblin spiders, is a family of spiders consisting of over 1,600 described species in about 113 genera worldwide, with total species diversity estimated at 2000 to 2500 species. The type genus of the family is ''Oonops'' K ...

* Orsolobidae * Pacullidae *

Periegopidae ''Periegops'' is a genus of spiders with six eyes instead of the usual eight. It is the only genus in its family (Periegopidae) and has three described species. It was long considered to be members of Sicariidae or Segestriidae until Raymond For ...

Pholcidae The Pholcidae are a family of araneomorph spiders. The family contains over 1,800 individual species of pholcids, including those commonly known as cellar spider, daddy long-legs spider, carpenter spider, daddy long-legger, vibrating spid ...

Scytodidae Spitting spiders (Scytodidae) is a family of araneomorph spiders first described by John Blackwall in 1864. It contains over 250 species in five genera, of which ''Scytodes'' is the best-known. Description Like recluse spiders and coneweb sp ...

Segestriidae Tube-dwelling spiders (Segestriidae) are a family of araneomorph spiders first described by Eugène Simon in 1893. It consists of five genera, two large and widespread, '' Segestria'' and ''Ariadna'', and three smaller genera, '' Citharoceps'', ...

Sicariidae Sicariidae is a family of six-eyed venomous spiders known for their potentially necrotic bites. The family consists of three genera and about 160 species. Well known spiders in this family include the brown recluse spider and the six-eyed sand ...

Telemidae, traditionally placed in Haplogynae, was not included in the analysis by Wheeler et al. However, it is placed in Synspermiata in other studies. The recently discovered haplogyne family Trogloraptoridae was also placed in Synspermiata. Several extinct families have also been placed into the haplogynes. *† Pholcochyroceridae

References

{{Araneae Araneomorphae Callovian first appearances Extant Middle Jurassic first appearances Historically recognized spider taxa