| Pholcoidea | |
|---|---|
 | |
| Pholcus sp., Pholcidae | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Subphylum: | Chelicerata |
| Class: | Arachnida |
| Order: | Araneae |
| Infraorder: | Araneomorphae |
| Superfamily: | Pholcoidea C.L. Koch, 1851 [1] |
| Families | |
See text. | |
The Pholcoidea or pholcoids are a superfamily of araneomorph spiders. The group has been circumscribed to contain the following three families: [1]
A phylogenetic study based on morphology has shown weak support for the monophyly of the group, as opposed to an earlier hypothesis that two of the families, Diguetidae and Plectreuridae, should be separated from the third in a larger superfamily, Sicarioidea. [2] Pholcoid families are placed in the Haplogynae, spiders with simpler copulatory structures than other araneomorphs. The internal phylogeny of the group is shown in the following cladogram: [3]
| |||||||||||||
The Mygalomorphae, or mygalomorphs, are an infraorder of spiders. 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. In 1802, Charles Athanase Walckenaer separated mygalomorph spiders into a separate genus, Mygale, leaving all other spiders in Aranea.
The Mesothelae are a suborder of spiders that includes a single living (extant) family, Liphistiidae, and a number of extinct families. This suborder is thought to form the sister group to all other living spiders, and to retain ancestral characters, such as a segmented abdomen with spinnerets in the middle and two pairs of book lungs. Members of Liphistiidae are medium to large spiders with eight eyes grouped on a tubercle. They are found only in China, Japan, and southeast Asia.
Spider taxonomy is that part of taxonomy that is concerned with the science of naming, defining and classifying all spiders, members of the Araneae order of the arthropod class Arachnida with about 46,000 described species. However, there are likely many species that have escaped the human eye to this day, and many specimens stored in collections waiting to be described and classified. It is estimated that only one third to one half of the total number of existing species have been described.
The Gnaphosoidea or gnaphosoids are a superfamily of araneomorph spiders with seven families. A 2014 study did not find the group to be monophyletic.
Lycosoidea is a clade or superfamily of araneomorph spiders. The traditional circumscription was based on a feature of the eyes. The tapetum is a reflective layer at the back of the eye, thought to increase sensitivity in low light levels. Lycosoids were then defined by having a "grate-shaped" tapetum. Research from the late 1990s onwards suggests that this feature has evolved more than once, possibly as many as five times, so that the original Lycosoidea is paraphyletic. Studies published in 2014 and 2015 suggest that a smaller group of families does form a clade.
Scytodoidea is a taxon of araneomorph spiders, at the rank of superfamily. It contains four families:
The Leptonetoidea are a superfamily of haplogyne araneomorph spiders with three families. Phylogenetic studies have provided weak support for the relationship among the families. The placement of one of the families within the Haplogynae has been questioned.
The Caponioidea or caponioids are a group of haplogyne araneomorph spiders that have been treated as superfamily with two members, the families Caponiidae and Tetrablemmidae. Phylogenetic studies from 1991 onwards have shown that the group is not monophyletic, being composed of two basal members of a larger clade. The precise members of that clade differ from study to study; one hypothesis is shown below.
The Dysderoidea are a clade or superfamily of araneomorph spiders. The monophyly of the group, initially consisting of the four families Dysderidae, Oonopidae, Orsolobidae and Segestriidae, has consistently been recovered in phylogenetic studies. In 2014, a new family, Trogloraptoridae, was created for a recently discovered species Trogloraptor marchingtoni. It was suggested that Trogloraptoridae may be the most basal member of the Dysderoidea clade. However, a later study found that Trogloraptoridae was placed outside the Dysderoidea and concluded that it was not part of this clade.
The Eresoidea or eresoids are a group of araneomorph spiders that have been treated as a superfamily. As usually circumscribed, the group contains three families: Eresidae, Hersiliidae and Oecobiidae. Studies and reviews based on morphology suggested the monophyly of the group; more recent gene-based studies have found the Eresidae and Oecobiidae to fall into different clades, placing doubt on the acceptability of the taxon. Some researchers have grouped Hersiliidae and Oecobiidae into the separate superfamily Oecobioidea, a conclusion supported in a 2017 study, which does not support Eresoidea.
The Deinopoidea or deinopoids are group of cribellate araneomorph spiders that may be treated as a superfamily. As usually circumscribed, the group contains two families: Deinopidae and Uloboridae.
The Agelenoidea or agelenoids are a superfamily or informal group of entelegyne araneomorph spiders. Phylogenetic studies since 2000 have not consistently recovered such a group, with more recent studies rejecting it.
The Dictynoidea or dictynoids are a group of araneomorph spiders that have been treated as a superfamily. The composition of the group has varied. Phylogenetic studies in the 21st century have failed to confirm the monophyly of the dictynoids as originally defined.
The Titanoecoidea or titanoecoids are a proposed taxon of araneomorph spiders at the superfamily rank. The taxon contains two families of spiders, Phyxelididae and Titanoecidae. Although some phylogenetic studies have shown these two families to form a clade, other studies have not, placing Titanoecidae outside the RTA clade while Phyxelididae is placed inside it. A 2011 classification of spider families leaves both Phyxelididae and Titanoecidae outside the RTA clade as "unplaced non-Orbiculariae families". The status of the group remains unclear as of December 2015.
The Austrochiloidea or austrochiloids are a group of araneomorph spiders, treated as a superfamily. The taxon contains two families of eight-eyed spiders:
The Haplogynae or haplogynes are one of the two main groups into which araneomorph spiders have traditionally been divided, the other being the Entelegynae. Morphological phylogenetic studies suggested that the Haplogynae formed a clade; more recent molecular phylogenetic studies refute this, although many of the ecribellate haplogynes do appear to form a clade, Synspermiata.
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; males have complex palpal bulbs. Molecular phylogenetic studies have supported the monophyly of Entelegynae.
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 confined to the New World, preferring deserts. Members of the genus Diguetia usually build their webs in shrubs or between cactus pads. They have the same eye arrangement as the venomous recluse spiders, but none are known to be harmful to humans.
Udubidae is a family of araneomorph spiders, most of whose members were formerly placed in the family Zorocratidae, which is no longer accepted.
Synspermiata is a clade of araneomorph spiders, comprising most of the former "haplogynes". They are united by having simpler genitalia than other araneomorph spiders, lacking a cribellum, and sharing an evolutionary history of synspermia – a particular way in which spermatozoa are grouped together when transferred to the female.