The Araneomorphae (also called the Labidognatha) are an infraorder of

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. They are distinguishable by chelicerae (fangs) that point diagonally forward and cross in a pinching action, in contrast to the Mygalomorphae (tarantulas and their close kin), where they point straight down. Araneomorphs comprise the vast majority of living spiders.

Distinguishing characteristics

Most spider species are Araneomorphae, which have

fangs A fang is a long, pointed tooth. In mammals, a fang is a modified maxillary tooth, used for biting and tearing flesh. In snakes, it is a specialized tooth that is associated with a venom gland (see snake venom). Spiders also have external ...

that face towards each other, increasing the orientations they can employ during prey capture. They have fewer

book lung A book lung is a type of respiration organ used for atmospheric gas exchange that is present in many arachnids, such as scorpions and spiders. Each of these organs is located inside an open ventral abdominal, air-filled cavity (atrium) and conn ...

s (when present), and the females typically live one year. The Mygalomorphae have

that face towards the ground, and which are parallel to the long axis of the spider's body, thus they have only one orientation they can employ during prey capture. They have four pairs of book lungs, and the females often live many years. Image:Atrax robustus.jpg, This '' Atrax robustus'' shows the orientation of Myglamorphae fangs. Image:Cheiracanthium punctorium frei 1 17 Forst Jungfernhdeide Jg 46 070920.jpg, This ''

Cheiracanthium punctorium ''Cheiracanthium punctorium'', one of several species commonly known as the yellow sac spider, is a spider found from central Europe to Central Asia. They reach a length of about 15 mm, and their bite can penetrate human skin; the bite has ...

'' shows the orientation of Araneomorphae fangs.

Spiders included

Almost all of the familiar spiders are included in the Araneomorphae group, the major exception being the

Tarantula Tarantulas comprise a group of large and often hairy spiders of the family Theraphosidae. , 1,040 species have been identified, with 156 genera. The term "tarantula" is usually used to describe members of the family Theraphosidae, although m ...

s. There are a few other Mygalomorphae species that live around homes or gardens, but they typically are relatively small and not easily noticed. The Araneomorphae, to the contrary, include the weavers of spiral webs; the cobweb spiders that live in the corners of rooms, and between windows and screens; the

crab spider The Thomisidae are a family of spiders, including about 170 genera and over 2,100 species. The common name crab spider is often linked to species in this family, but is also applied loosely to many other families of spiders. Many members of thi ...

s that lurk on the surfaces of flowers in gardens; the

jumping spider Jumping spiders are a group of spiders that constitute the family Salticidae. As of 2019, this family contained over 600 described genera and over 6,000 described species, making it the largest family of spiders at 13% of all species. Jumping spi ...

s that are visible hunting on surfaces; the

wolf spider Wolf spiders are members of the family Lycosidae (). They are robust and agile hunters with excellent eyesight. They live mostly in solitude, hunt alone, and do not spin webs. Some are opportunistic hunters, pouncing upon prey as they find it or ...

s that carpet hunting sites in sunny spots; and the large huntsman spiders.

Systematics

In older schemes, the Araneomorphae were divided into two lineages, the ''Hypochilae'' (containing only the family Hypochilidae), and the ''Neocribellatae''. The Neocribellatae were in turn divided into the Austrochiloidea, and the two series Haplogynae and Entelogynae, each containing several superfamilies.

Molecular phylogenetic Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

studies have shown that the Haplogyne in particular are not a

monophyletic 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 gr ...

group. A 2020 study suggested the relationships among the major groups were as shown in the following cladogram. The blue bar to the right shows the former Haplogynae in the sense of Coddington (2005).

Distinguishing characteristics

Spiders included

Systematics

Table of families

Notes

References

Citations

External links