|Nephila inaurata (Nephilidae)|
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 close kin), where they point straight down. Araneomorphs comprise the vast majority of living spiders.
Most spider species are Araneomorphae, which have fangs that face towards each other, increasing the orientations they can employ during prey capture. They have fewer book lungs (when present), and the females typically live one year.
The Mygalomorphae have fangs 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.
Almost all of the familiar spiders are included in the Araneomorphae group, the major exception are the Tarantulas. 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 spiders that lurk on the surfaces of flowers in gardens; the jumping spiders that are visible hunting on surfaces; the wolf spiders that carpet hunting sites in sunny spots; and the large huntsman spiders.
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 studies have shown that the Haplogyne in particular are not a monophyletic group. A 2020 study suggested the relationships among the major groups were as shown in the following cladogram.
This relationship was supported in a 2021 study, except for the division of Leptonetidae into two families:The added yellow shading shows the former Haplogynae in the sense of Coddington (2005).
|Agelenidae||78||1282||araneomorph funnel-web spiders||Hobo spider|
|Amaurobiidae||49||274||tangled nest spiders||Callobius claustrarius|
|Anyphaenidae||56||563||anyphaenid sac spiders||Yellow ghost spider|
|Araneidae||174||3128||orb-weaver spiders||Zygiella x-notata|
|Archaeidae||5||90||pelican spiders||Madagascarchaea gracilicollis|
|Austrochilidae||3||10||Tasmanian cave spider|
| Cheiracanthiidae |
|Clubionidae||15||618||sac spiders||Clubiona trivialis|
|Corinnidae||67||779||dark sac spiders||Castianeira sp.|
|Ctenidae||47||525||tropical wolf spiders||Brazilian wandering spiders|
|Deinopidae||2||65||net-casting spiders||Rufous net-casting spider|
|Desidae||60||297||intertidal spiders||Phryganoporus candidus|
|Drymusidae||2||17||false violin spiders|
|Dysderidae||24||564||woodlouse hunter spiders||Woodlouse spider|
|Eresidae||9||98||velvet spiders||Eresus sandaliatus|
|Filistatidae||19||164||crevice weavers||Southern house spider|
|Gnaphosidae||158||2532||flat-bellied ground spiders||Drassodes cupreus|
|Gradungulidae||7||16||large-clawed spiders||Carrai cave spider|
|Hahniidae||23||346||dwarf sheet spiders|
|Hersiliidae||16||181||tree trunk spiders||Hersilia savignyi|
|Hypochilidae||2||12||lampshade spiders||Hypochilus thorelli|
|Leptonetidae||21||346||Tooth cave spider|
|Linyphiidae||607||4566||dwarf / money spiders||Linyphia triangularis|
|Liocranidae||31||272||liocranid sac spiders|
|Lycosidae||124||2419||wolf spiders||Lycosa tarantula|
|Mimetidae||12||152||pirate spiders||Oarces reticulatus|
|Miturgidae||29||130||long-legged sac spiders|
|Nesticidae||16||278||cave cobweb spiders||Nesticella marapu|
|Ochyroceratidae||20||216||midget ground weavers||Theotima minutissima|
|Oecobiidae||6||113||disc web spiders||Oecobius navus|
|Oonopidae||114||1801||dwarf hunting spiders||Oonops domesticus|
|Oxyopidae||9||457||lynx spiders||Green lynx spider|
|Philodromidae||30||539||philodromid crab spiders||Philodromus dispar|
|Pholcidae||77||1666||daddy long-legs spiders||Pholcus phalangioides|
|Pisauridae||51||356||nursery web spiders||Pisaura mirabilis|
|Salticidae||635||6080||jumping spiders||Zebra spider|
|Scytodidae||5||248||spitting spiders||Scytodes thoracica|
|Segestriidae||4||130||tubeweb spiders||Segestria florentina|
|Selenopidae||10||257||wall spiders||Selenops radiatus|
|Sicariidae||3||1623||recluse spiders||Brown recluse|
|Sparassidae||88||1224||huntsman spiders||Avondale spider|
|Symphytognathidae||8||73||dwarf orb-weavers||Patu digua|
|Telemidae||10||79||long-legged cave spiders|
|Tetragnathidae||48||996||long jawed orb-weavers||Orchard spider|
|Theridiidae||124||2503||cobweb spiders||Redback spider|
|Theridiosomatidae||19||124||ray spiders||Theridiosoma gemmosum|
|Thomisidae||170||2171||crab spiders||Goldenrod spider|
|Uloboridae||19||283||hackled orb-weavers||Uloborus walckenaerius|
|Zodariidae||85||1141||ant spiders||Zodarion germanicum|
The Mygalomorphae, or mygalomorphs, are an infraorder of spiders, and comprise one of three major groups of living spiders with over 3000 species, found on all continents except Antarctica. Many members are known as trapdoor spiders due to them forming trapdoors over their burrows. Other prominent groups include Australian funnel web spiders, and tarantulas, with the latter accounting for around one third of all mygalomorphs.
The chelicerae are the mouthparts of the Chelicerata, an arthropod group that includes arachnids, horseshoe crabs, and sea spiders. Commonly referred to as "jaws", chelicerae may be shaped as either articulated fangs, or similarly to pincers. Some chelicerae, such as those found on nearly all spiders, are hollow and contain venom glands, and are used to inject venom into prey or a perceived threat. In Pisaurina mira, also known as the nursery web spider, the chelicerae are utilized to snatch the prey once it becomes within reach, facilitating the "sit-and-wait ambush predator" behavior. Both pseudoscorpions and harvestmen have structures on their chelicerae that are used for grooming.
Atracidae is a family of mygalomorph spiders, commonly known as Australian funnel-web spiders or atracids. It has been included as a subfamily of the Hexathelidae, but is now recognized as a separate family. All members of the family are native to Australia. Atracidae consists of three genera: Atrax, Hadronyche, and Illawarra, comprising 35 species. Some members of the family produce venom that is dangerous to humans, and bites by spiders of six of the species have caused severe injuries to victims. The bites of the Sydney funnel-web spider and northern tree-dwelling funnel-web spider are potentially deadly, but no fatalities have occurred since the introduction of modern first-aid techniques and antivenom.
The Mesothelae are a suborder of spiders that includes a single 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. The oldest known Mesothelae spiders are known from the Carboniferous, over 300 million years ago.
The spider family Liphistiidae, recognized by Tamerlan Thorell in 1869, comprises 8 genera and about 100 species of medium-sized spiders from Southeast Asia, China, and Japan. They are among the most basal living spiders, belonging to the suborder Mesothelae. In Japan, the Kimura spider is well known.
Ctenizidae is a small family of mygalomorph spiders that construct burrows with a cork-like trapdoor made of soil, vegetation, and silk. They may be called trapdoor spiders, as are other, similar species, such as those of the families Liphistiidae, Barychelidae, and Cyrtaucheniidae, and some species in the Idiopidae and Nemesiidae. The name comes from the distinctive behavior of the spiders to construct trapdoors, and ambush prey from beneath them.
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 they have intersecting fangs, with the exception of some species which have chelicerae in an angle that is neither orthognathous or labidognathous. These long-legged spiders build typical "lampshade" style webs under overhangs and in caves. In the United States the fauna is primarily associated with the Appalachian, Rocky and California Mountains. Ten of the known species are found in these ranges, all in the genus Hypochilus. The genus Ectatosticta is found in China.
Crevice weaver spiders (Filistatidae) comprise cribellate spiders with features that have been regarded as "primitive" for araneomorph spiders. They are weavers of funnel or tube webs. The family contains 18 genera and more than 120 described species worldwide.
Hexathelidae is a family of mygalomorph spiders. It is one of a number of families and genera of spiders known as funnel-web spiders. In 2018, the family was substantially reduced in size by genera being moved to three separate families: Atracidae, Macrothelidae and Porrhothelidae. Atracidae includes the most venomous species formerly placed in Hexathelidae.
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 more than 48,500 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.
Dwarf tarantulas, also known as sheet funnel-web spiders are a type of spider from the family Mecicobothriidae. Dwarf tarantulas are one of several families of the suborder Mygalomorphae; this larger group also includes the true tarantulas.
Cribellum literally means "little sieve", and in biology the term generally applies to anatomical structures in the form of tiny perforated plates.
Austrochilidae is a small spider family with nine species in two genera. Austrochilus and Thaida are endemic to the Andean forest of central and southern Chile and adjacent Argentina.
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 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 Opisthothelae are spiders within the order Araneae, consisting of the Mygalomorphae and the Araneomorphae, but excluding the Mesothelae. The Opisthothelae are sometimes presented as an unranked clade and sometimes as a suborder of the Araneae. In the latter case, the Mygalomorphae and Araneomorphae are treated as infraorders.
The anatomy of spiders includes many characteristics shared with other arachnids. These characteristics include bodies divided into two tagmata, eight jointed legs, no wings or antennae, the presence of chelicerae and pedipalps, simple eyes, and an exoskeleton, which is periodically shed.
Tarantulas comprise a group of large and often hairy spiders of the family Theraphosidae. Currently, 1,010 species have been identified. The term "tarantula" is usually used to describe members of the family Theraphosidae, although many other members of the same infraorder (Mygalomorphae) are commonly referred to as "tarantulas" or "false tarantulas". Some of the more common species have become popular in the exotic pet trade. Many New World species kept as pets have setae known as urticating hairs that can cause irritation to the skin, and in extreme cases, cause damage to the eyes.
Spiders 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 diversity among all orders of organisms. Spiders are found worldwide on every continent except for Antarctica, and have become established in nearly every land habitat. As of August 2021, 49,623 spider species in 129 families have been recorded by taxonomists. However, there has been dissension within the scientific community as to how all these families should be classified, as evidenced by the over 20 different classifications that have been proposed since 1900.
Eucteniza is a genus of trapdoor spiders in the family Euctenizidae containing at least 14 species occurring in Mexico and the southern United States. Species are distinguished by a softened rear portion of the carapace, and males possess large spines on the first two pairs of walking legs that are used to hold females during mating. Like other trapdoor spiders they create burrows with a hinged lid, from which they await passing insects and other arthropods to prey upon. Many species are known from only one or two localities, or from only male specimens. More species are expected to be discovered. Eucteniza is closely related to spiders of the genera Entychides and Neoapachella.