The

order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of ...

Trigonotarbida is a group of extinct

arachnid Arachnida () is a class of joint-legged invertebrate animals (arthropods), in the subphylum Chelicerata. Arachnida includes, among others, spiders, scorpions, ticks, mites, pseudoscorpions, harvestmen, camel spiders, whip spiders and vinegar ...

s whose

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

record extends from the late

Silurian The Silurian ( ) is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the shortest period of the Paleoz ...

to the early

Permian The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleo ...

( Pridoli to Sakmarian).Dunlop, J. A., Penney, D. & Jekel, D. 2020
A summary list of fossil spiders and their relatives
In World Spider Catalog. Natural History Museum Bern, online at http://wsc.nmbe.ch, version 20.5 These animals are known from several localities in

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

and

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and th ...

, as well as a single record from

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the List of South American countries by area, second-largest ...

. Trigonotarbids can be envisaged as

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 ...

-like arachnids, but without silk-producing

spinneret A spinneret is a silk-spinning organ of a spider or the larva of an insect. Some adult insects also have spinnerets, such as those borne on the forelegs of Embioptera. Spinnerets are usually on the underside of a spider's opisthosoma, and are ...

s. They ranged in size from a few millimetres to a few centimetres in body length and had segmented abdomens (

opisthosoma The opisthosoma is the posterior part of the body in some arthropods, behind the prosoma (cephalothorax). It is a distinctive feature of the subphylum Chelicerata (arachnids, horseshoe crabs and others). Although it is similar in most respects to ...

), with the dorsal exoskeleton (

tergites A ''tergum'' (Latin for "the back"; plural ''terga'', associated adjective tergal) is the dorsal ('upper') portion of an arthropod segment other than the head. The anterior edge is called the 'base' and posterior edge is called the 'apex' or 'mar ...

) across the backs of the animals' abdomens, which were characteristically divided into three or five separate plates. Probably living as predators on other

arthropod Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and cuticle made of chiti ...

s, some later trigonotarbid species were quite heavily armoured and protected themselves with spines and tubercles. About seventy species are currently known, with most fossils originating from the

Carboniferous The Carboniferous ( ) is a geologic period and system of the Paleozoic that spans 60 million years from the end of the Devonian Period million years ago ( Mya), to the beginning of the Permian Period, million years ago. The name ''Carboniferou ...

coal measures In lithostratigraphy, the coal measures are the coal-bearing part of the Upper Carboniferous System. In the United Kingdom, the Coal Measures Group consists of the Upper Coal Measures Formation, the Middle Coal Measures Formation and the Lower Coa ...

Historical background

The first trigonotarbid was described in 1837 from the coal measures of

Coalbrookdale Coalbrookdale is a village in the Ironbridge Gorge in Shropshire, England, containing a settlement of great significance in the history of iron ore smelting. It lies within the civil parish called the Gorge. This is where iron ore was first ...

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe ...

by the famous English geologist Dean

William Buckland William Buckland DD, FRS (12 March 1784 – 14 August 1856) was an English theologian who became Dean of Westminster. He was also a geologist and palaeontologist. Buckland wrote the first full account of a fossil dinosaur, which he named ' ...

. He believed it to be a fossil

beetle Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 describ ...

and named it ''Curculoides prestvicii''. A much better preserved example was later discovered from

Coseley Coseley ( ) is a village in the north of the Dudley Metropolitan Borough, in the English West Midlands. Part of the Black Country, it is situated approximately north of Dudley itself, on the border with Wolverhampton. Though it is a part o ...

near

Dudley Dudley is a large market town and administrative centre in the county of West Midlands, England, southeast of Wolverhampton and northwest of Birmingham. Historically an exclave of Worcestershire, the town is the administrative centre of the ...

; also in the English

West Midlands conurbation The West Midlands conurbation is the large conurbation that includes the cities of Birmingham and Wolverhampton and the towns of Sutton Coldfield, Dudley, Walsall, West Bromwich, Solihull, Stourbridge and Halesowen in the English West Midland ...

. Described in 1871 by Henry Woodward, he correctly identified it as an arachnid and renamed it '' Eophrynus prestvicii''—whereby the genus name comes from (', meaning 'dawn'), and ''

Phrynus ''Phrynus'' is a genus of whip spiders found in tropical and subtropical regions, mostly in the new world. Appearance Like other species of the order Amblypygi, species of the genus ''Phrynus'' are dorso-ventrally flattened arachnids with elonga ...

'', a genus of living whip spider (

Amblypygi Amblypygi is an ancient order of arachnid chelicerate arthropods also known as African cave-dwelling spiders, whip spiders and tailless whip scorpions (not to be confused with whip scorpions or vinegaroons that belong to the related order Thelyph ...

). Woodward subsequently described another trigonotarbid, ''Brachypyge carbonis'', from the coal measures of

Mons Mons (; German and nl, Bergen, ; Walloon and pcd, Mont) is a city and municipality of Wallonia, and the capital of the province of Hainaut, Belgium. Mons was made into a fortified city by Count Baldwin IV of Hainaut in the 12th century. T ...

Belgium Belgium, ; french: Belgique ; german: Belgien officially the Kingdom of Belgium, is a country in Northwestern Europe. The country is bordered by the Netherlands to the north, Germany to the east, Luxembourg to the southeast, France to ...

; although this fossil is known only from its abdomen and was initially mistaken for those of a

crab Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen) ( el, βραχύς , translit=brachys = short, / = tail), usually hidden entirely under the thorax. They live in all th ...

A new arachnid order

In 1882, the German

zoologist Zoology ()The pronunciation of zoology as is usually regarded as nonstandard, though it is not uncommon. is the branch of biology that studies the animal kingdom, including the structure, embryology, evolution, classification, habits, and d ...

Ferdinand Karsch described a number of fossil arachnids from the coal measures of Neurode in

Silesia Silesia (, also , ) is a historical region of Central Europe that lies mostly within Poland, with small parts in the Czech Silesia, Czech Republic and Germany. Its area is approximately , and the population is estimated at around 8,000,000. S ...

(now

Poland Poland, officially the Republic of Poland, is a country in Central Europe. It is divided into 16 administrative provinces called voivodeships, covering an area of . Poland has a population of over 38 million and is the fifth-most populou ...

), including one he named ''Anthracomartus voelkelianus'' in honour of Herr Völkel, the foreman of the mine where it was discovered. This species was raised to a new, extinct, arachnid order which Karsch called Anthracomarti. The name is derived from ('), the Greek word for

coal Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is formed when ...

. A number of other fossils which would eventually be placed in Trigonotarbida were discovered around this time.

Hanns Bruno Geinitz Hanns Bruno Geinitz (16 October 1814 – 28 January 1900) was a German geologist, born at Altenburg, the capital of Saxe-Altenburg. He was educated at the universities of Berlin and Jena, and gained the foundations of his geological knowledge ...

described ''Kreischeria wiedei'' from the coal measures of

Zwickau Zwickau (; is, with around 87,500 inhabitants (2020), the fourth-largest city of Saxony after Leipzig, Dresden and Chemnitz and it is the seat of the Zwickau District. The West Saxon city is situated in the valley of the Zwickau Mulde (German: ' ...

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwee ...

, although he interpreted it as a fossil

pseudoscorpion Pseudoscorpions, also known as false scorpions or book scorpions, are small, scorpion-like arachnids belonging to the order Pseudoscorpiones, also known as Pseudoscorpionida or Chelonethida. Pseudoscorpions are generally beneficial to humans sin ...

. Johann Kušta described ''Anthracomartus krejcii'' from

Rakovník Rakovník (, german: Rakonitz) is a town in the Central Bohemian Region of the Czech Republic. It has about 15,000 inhabitants. The town centre is well preserved and is protected by law as an urban monument zone. Administrative parts Rakovník ...

in the

Czech Republic The Czech Republic, or simply Czechia, is a landlocked country in Central Europe. Historically known as Bohemia, it is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the southeast. The ...

, and published further descriptions in a number of subsequent papers. In 1884, Samuel Hubbard Scudder described ''Anthracomartus trilobitus'' from

Fayetteville, Arkansas Fayetteville () is the second-largest city in Arkansas, the county seat of Washington County, and the biggest city in Northwest Arkansas. The city is on the outskirts of the Boston Mountains, deep within the Ozarks. Known as Washington unt ...

—the first trigonotarbid from

Relationships

Early studies tended to confuse trigonotarbids with other living or extinct groups of arachnids; particularly harvestmen (

Opiliones The Opiliones (formerly Phalangida) are an order of arachnids colloquially known as harvestmen, harvesters, harvest spiders, or daddy longlegs. , over 6,650 species of harvestmen have been discovered worldwide, although the total number of ext ...

). Petrunkevitch's division of the trigonotarbids into two, unrelated, orders was noted above. In detail, he divided the arachnids into suborders based on the width of the division between the two parts of the body (the

prosoma The cephalothorax, also called prosoma in some groups, is a tagma of various arthropods, comprising the head and the thorax fused together, as distinct from the abdomen behind. (The terms ''prosoma'' and ''opisthosoma'' are equivalent to ''cepha ...

and

). Anthracomartida and another extinct order, Haptopoda, were grouped into a subclass Stethostomata defined by a broad division of the body and downward-hanging mouthparts. Trigonotarbida was placed in its own subclass Soluta and defined as having a division of the body which was variable in width. Petrunkevitch's scheme was largely followed in subsequent studies of fossil arachnids.

Pantetrapulmonata

In the 1980s, Bill Shear and colleagues carried out an important study on well preserved Mid Devonian trigonotarbids from

Gilboa, New York Gilboa is a town in Schoharie County, New York, United States. The population was 1,215 at the 2000 census. The Town of Gilboa is in the southern part of the county and is southwest of Albany. History The town was first settled around 1760 ...

. They questioned whether it was appropriate to define a group of animals on a variable character state and carried out the first

cladistic Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups ("clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived char ...

analysis of fossil and living arachnids. They showed that trigonotarbids are closely related to a group of arachnids which have gone under various names (Caulogastra, Arachnidea, ''etc.''), but for which the name

Tetrapulmonata Tetrapulmonata is a non-ranked supra-ordinal clade of arachnids. It is composed of the extant orders Thelyphonida (whip scorpions), Schizomida (short-tailed whip scorpions), Amblypygi (tail-less whip scorpions) and Araneae (spiders). It is th ...

has become most widespread. Members of the Tetrapulmonata include

s (

Araneae 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 dive ...

), whip spiders (

), whip scorpions (

Thelyphonida Thelyphonida is an arachnid order comprising invertebrates commonly known as whip scorpions or vinegaroons (also spelled vinegarroons and vinegarones). They are often called uropygids in the scientific community based on an alternative name for ...

) and shorttailed whipscorpion ( Schizomida) and, together with trigonotarbids, share characters like two pairs of

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 and similar mouthparts with fangs operating rather like a pocket knife. In a 2007 study of arachnid relationships, the Shear ''et al.'' hypothesis was largely supported and a group Pantetrapulmonata was proposed which comprises Trigonotarbida + Tetrapulmonata. This has since been corroborated in more recent cladistic analyses.

Trigonotarbids and ricinuleids

In 1892, Ferdinand Karsch suggested that the rare and rather bizarre-looking ricinuleids (

Ricinulei Ricinulei is a small order of arachnids. Like most arachnids, they are predatory, eating small arthropods. They occur today in west-central Africa ('' Ricinoides'') and the Neotropics ('' Cryptocellus'' and '' Pseudocellus'') as far north as Texa ...

) were the last living descendants of the trigonotarbids. A similar hypothesis was reintroduced by Dunlop, who pointed out distinct similarities and possible

sister group In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

relationship between these arachnid groups. Both have opisthosomal tergites divided into median and lateral plates and both have a complicated coupling mechanism between the prosoma and the opisthosoma which 'locks' the two halves of the body together. Although cladistic analysis has tended to recover ricinuleids in their traditional position closely related to mites and ticks, further discoveries have revealed that the tip of the pedipalp ends in a small claw in both trigonotarbids and ricinuleids. If the hypothesis is true, ricinuleids, despite the lack of tetrapulmonate key characters (e.g. book lungs), may represent part of the pantetrapulmonate clade alongside trigonotarbids as well.

Internal relationships

The first cladistic analysis of the trigonotarbids was published in 2014. This recovered the families

Anthracomartidae Anthracomartidae, first described by Haase, 1890, is a family of the extinct arachnid order Trigonotarbida. It is likely to be most closely related to the Archaeomartidae, based on a 2014 cladistic analysis, within the clade (Palaeocharinus (Arch ...

, Anthracosironidae, and Eophrynidae as monophyletic. In contrast Trigonotarbidae, Aphantomartidae, Palaeocharinidae, and Kreischeriidae were not. Two clades were consistently recovered with strong support—('' Palaeocharinus'' (Archaeomartidae + Anthracomartidae)), and '' Lissomartus'' as sister group the 'eophrynid assemblage' ('' Aphantomartus'' ('' Alkenia'' ('' Pseudokreischeria'' ('' Kreischeria'' ('' Eophrynus'' + '' Pleophrynus''))))).

Description

20201108 Trigonotarbida dorsal ventral morphology

20201109 Trigonotarbida sagittal external morphology

Trigonotarbids superficially resemble

s, but can be easily recognised by having

on the dorsal side of the opisthosoma divided into median and lateral plates. This character is shared with ricinuleids (

) (see also Ricinulei#Relationships). As in other arachnids, the body is divided into a

(or cephalothorax) and

(or abdomen). Body length ranges from a couple of millimetres up to about .

Prosoma

The prosoma is covered by the

carapace A carapace is a dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tortoises, the unde ...

and always bears a pair of median eyes. In the probably basal families Palaeocharinidae,

—and perhaps also Anthracosironidae—there is an additional pair of lateral eye tubercles which, at least in palaeocharinids, appear to have borne a series of individual lenses. In this sense palaeocharinids seem to be in the process of reducing a

compound eye A compound eye is a visual organ found in arthropods such as insects and crustaceans. It may consist of thousands of ommatidia, which are tiny independent photoreception units that consist of a cornea, lens, and photoreceptor cells which disti ...

. Anterior margin of the carapace protrude into a projection referred to as clypeus. The

chelicerae The chelicerae () are the mouthparts of the subphylum 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 similarl ...

are of the "pocket-knife" type consisting of a basal segment and a sharp, curving fang. The chelicerae are described as ''paleognathic'': the fangs are held parallel to one another, like those of mesothele and

mygalomorph 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 t ...

spiders, but the chelicerae hang downwards like those of

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 ...

spiders. There is no evidence in well-preserved fossils for the opening of a venom gland, thus trigonotarbids were probably not

venomous Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved ''venom apparatus'', such as fangs or a sti ...

. The chelicerae may have been slightly retractable into the prosoma. Well-preserved palaeocharinids show evidence for a small, slit-like mouth with an upper lip (a labrum or rostrum) and a lower lip (or labium). Inside the mouth there is some sort of filtering system formed from hairs or platelets which strongly suggests that trigonotarbids (like spiders and many other arachnids) could eat only preorally digested, liquified prey. The

pedipalp Pedipalps (commonly shortened to palps or palpi) are the second pair of appendages of chelicerates – a group of arthropods including spiders, scorpions, horseshoe crabs, and sea spiders. The pedipalps are lateral to the chelicerae ("jaws") an ...

s have the typical arachnid structure with a coxa, trochanter, femur, patella, tibia and tarsus. They are ''pediform'', i.e. they look like small legs and were not highly modified. There is no evidence for a special sperm transfer device as in the modified palpal organ of male spiders. In at least the palaeocharinids and anthracomartids the tip of the pedipalp is modified into a small chela (claw) formed from the tarsal claw (or apotele) and a projection from the tarsus. As mentioned above, a very similar arrangement is seen at the end of the pedipalp in

. The walking legs again follow the typical arachnid plan with a coxa, trochanter, femur, patella, tibia, metatarsus and tarsus. The coxae surround a single sternum. In well preserved palaeocharinids there is a ring, or annulus, around the trochanter–femur joint which may be the remains of an earlier leg segment. The legs are largely unmodified, although in Anthracosironidae the forelegs are quite large and spiny, presumably to help catch prey. The legs end in three claws, two large ones and a smaller median claw.

Opisthosoma

The opisthosoma is largely suboval in outline with a flatten dorsal surface. It compose of 12 segments, with some of them had undergone degrees of fusion or reduction, hence the previous misinterpretation of around 8 to 11 segments.

Tergite A ''tergum'' (Latin for "the back"; plural ''terga'', associated adjective tergal) is the dorsal ('upper') portion of an arthropod segment other than the head. The anterior edge is called the 'base' and posterior edge is called the 'apex' or 'mar ...

of the first segment partially covered by the posterior margin of preceding carapace, forming a complicated coupling mechanism known as 'locking ridge'.

s of segment 2 to 8 (segment 9 in some species) were all laterally divided into 3 (one median and two lateral) plates, with those of segment 2 and 3 fused to each other in most species. However, the corresponding tergites of the family

are further subdivided into 5 plates. The last 3 segments are usually only visible from the ventral side, with the 2 final segments constricted into a tiny ring-like section known as pygidium. Ventral side of opisthosomal segment 2 to 9 covered by series of lung-bearing opercula (2 and 3) and curved

sternite The sternum (pl. "sterna") is the ventral portion of a segment of an arthropod thorax or abdomen. In insects, the sterna are usually single, large sclerites, and external. However, they can sometimes be divided in two or more, in which case th ...

s (4 to 9). The first segment apparently lacking any ventral plates. Just like other lung-bearing

s (

scorpion Scorpions are predatory arachnids of the order Scorpiones. They have eight legs, and are easily recognized by a pair of grasping pincers and a narrow, segmented tail, often carried in a characteristic forward curve over the back and always en ...

and tetrapulmonate), the

s of trigonotarbids formed by layers of trabecula-bearing lamellae, which is a feature adapted to a terrestrial, air-breathing lifestyle. A pair of ventral sacs located between the posterior operculum and following sternite had been observed in some species.

Paleobiology

In July 2014 scientists used computer-based techniques to re-create a possible walking gait for the animal. A subsequent review article suggested by comparison with mites, with presumably similar lifestyle and environment, a metachronal rather than alternating leg coordination was more likely. Subsequent work by the researchers behind the initial publication used simulation approaches to assess the efficiency of a range of gaits using an updated trigonotarbid model.

Included taxa

As of 2020, 70 valid

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...

had been included under Trigonotarbida as follows: ; plesion taxa * '' Palaeotarbus'' Dunlop, 1999 ** '' Palaeotarbus jerami'' (Dunlop, 1996) – Late Silurian, England ; Palaeocharinidae Hirst, 1923 * '' Aculeatarbus'' Shear, Selden & Rolfe, 1987 ** '' Aculeatarbus depressus'' Shear, Selden & Rolfe, 1987 – Mid Devonian, United States * '' Gelasinotarbus'' Shear, Selden & Rolfe, 1987 ** '' Gelasinotarbus bifidus'' Shear, Selden & Rolfe, 1987 – Mid Devonian, United States ** '' Gelasinotarbus bonamoae'' Shear, Selden & Rolfe, 1987 – Mid Devonian, United States ** '' Gelasinotarbus heptops'' Shear, Selden & Rolfe, 1987 – Mid Devonian, United States ** '' Gelasinotarbus reticulatus'' Shear, Selden & Rolfe, 1987 – Mid Devonian, United States * '' Gigantocharinus'' Shear, 2000 ** '' Gigantocharinus szatmaryi'' Shear, 2000 – Late Devonian, United States * '' Gilboarachne'' Shear, Selden & Rolfe, 1987 ** '' Gilboarachne griersoni'' Shear, Selden & Rolfe, 1987 – Mid Devonian, United States * '' Palaeocharinus'' Hirst, 1923 ** '' Palaeocharinus calmani'' Hirst, 1923 – Early Devonian, Scotland ** '' Palaeocharinus hornei'' Hirst, 1923 – Early Devonian, Scotland ** '' Palaeocharinus kidstoni'' Hirst, 1923 – Early Devonian, Scotland ** '' Palaeocharinus rhyniensis'' Hirst, 1923 – Early Devonian, Scotland ** '' Palaeocharinus scourfieldi'' Hirst, 1923 – Early Devonian, Scotland ** '' Palaeocharinus tuberculatus'' Fayers, Dunlop & Trewin, 2005 – Early Devonian, Scotland *'' Spinocharinus'' Poschmann & Dunlop, 2011 **'' Spinocharinus steinmeyeri'' Poschman & Dunlop, 2011 - Devonian, Bürdenbach ; Archaeomartidae Haase, 1890 * '' Archaeomartus'' Størmer, 1970 ** '' Archaeomartus levis'' Størmer, 1970 - Devonian, Alken an der Mosel ;

Haase, 1890 *synonyms **= Promygalidae Frič, 1904 **= Brachypygidae Pocock, 1911 **= Coryphomartidae Petrunkevitch, 1945 **= Pleomartidae Petrunkevitch, 1945 *'' Anthracomartus'' Karsch, 1882 ** synonyms *** = ''Brachylycosa'' Frič, 1904 *** = ''Cleptomartus'' Petrunkevitch, 1949 *** = ''Coryphomartus'' Petrunkevitch, 1945 *** = ''Cryptomartus'' Petrunkevitch, 1945 *** = ''Oomartus'' Petrunkevitch, 1953 *** = ''Perneria'' Frič, 1904 *** = ''Pleomartus'' Petrunkevitch, 1945 *** = ''Promygale'' Frič, 1901 ** '' Anthracomartus bohemica'' (Frič, 1901) – Late Carboniferous, Czech Republic ** '' Anthracomartus carcinoides'' (Frič, 1901) – Late Carboniferous, Czech Republic *** synonyms **** = ''Promygale rotunda'' Frič, 1901 **** = ''Perneria salticoides'' Frič, 1904 ** '' Anthracomartus elegans'' Frič, 1901 – Late Carboniferous, Czech Republic ** '' Anthracomartus hindi'' Pocock, 1911 – Late Carboniferous, England *** synonyms **** = ''Cleptomartus hangardi'' Guthörl, 1965 **** = ''Cryptomartus meyeri'' Guthörl, 1964 **** = ''Cleptomartus planus'' Petrunkevitch, 1949 **** = ''Cryptomartus rebskei'' Brauckmann, 1984 ** '' Anthracomartus granulatus'' Frič, 1904 – Late Carboniferous, Poland ** '' Anthracomartus janae'' (Opluštil, 1986) – Late Carboniferous, Czech Republic ** '' Anthracomartus kustae'' Petrunkevitch, 1953 – Late Carboniferous, Czech Republic ** '' Anthracomartus minor'' Kušta, 1884 – Late Carboniferous, Czech Republic *** synonym **** = ''Anthracomartus socius'' Kušta, 1888 ** '' Anthracomartus nyranensis'' (Petrunkevitch, 1953) – Late Carboniferous, Czech Republic ** '' Anthracomartus palatinus'' Ammon, 1901 – Late Carboniferous, Germany ** '' Anthracomartus priesti'' Pocock, 1911 – Late Carboniferous, England *** synonyms ****= ''Anthracomartus denuiti'' Pruvost, 1922 ****= ''Cleptomartus plautus'' Petrunkevitch, 1949 ** '' Anthracomartus radvanicensis'' (Opluštil, 1985) – Late Carboniferous, Czech Republic ** '' Anthracomartus triangularis'' Petrunkevitch, 1913 – Late Carboniferous, Canada ** '' Anthracomartus trilobitus'' Scudder, 1884 – Late Carboniferous, United States ** '' Anthracomartus voelkelianus'' Karsch, 1882 – Late Carboniferous, Poland * '' Brachypyge'' Woodward, 1878 ** '' Brachypyge carbonis'' Woodward, 1878 – Late Carboniferous, Belgium * '' Maiocercus'' Pocock, 1911 ** '' Maiocercus celticus'' (Pocock, 1902) – Late Carboniferous, Europe ***synonym ****= ''Maiocercus orbicularis'' Gill, 1911 ; Anthracosironidae Pocock, 1903 * '' Anthracosiro'' Pocock, 1903 ** '' Anthracosiro fritschii'' Pocock, 1903 – Late Carboniferous, Europe ***synonym ****= ''Anthracosiro elongatus'' Waterlot, 1934 ** '' Anthracosiro woodwardi'' Pocock, 1903 – Late Carboniferous, Europe ***synonyms ****= ''Anthracosiro corsini'' Pruvost, 1926 ****= ''Anthracosiro latipes'' Gill, 1909 * '' Arianrhoda'' Dunlop & Selden, 2004 ** '' Arianrhoda bennetti'' Dunlop & Selden, 2004 – Early Devonian, Wales *'' Vratislavia'' Frič, 1904 **'' Vratislavia silesica'' (Roemer, 1878) - Carboniferous, Silesia ; Trigonotarbidae Petrunkevitch, 1949 * '' Trigonotarbus'' Pocock, 1911 ** '' Trigonotarbus arnoldi'' Petrunkevitch, 1955 – Late Carboniferous, France ** '' Trigonotarbus johnsoni'' Pocock, 1911 – Late Carboniferous, England ** '' Trigonotarbus stoermeri'' Schultka, 1991 – Early Devonian, Germany ; Lissomartidae Dunlop, 1995 * '' Lissomartus'' Petrunkevitch, 1949 ** '' Lissomartus carbonarius'' (Petrunkevitch, 1913) – Late Carboniferous, United States ** '' Lissomartus schucherti'' (Petrunkevitch, 1913) – Late Carboniferous, United States ; Aphantomartidae Petrunkevitch, 1945 * synonym **= Trigonomartidae Petrunkevitch, 1949 *'' Alkenia'' Størmer, 1970 **'' Alkenia mirabilis'' Størmer, 1970 - Devonian, Alken an der Mosel *'' Aphantomartus'' Pocock, 1911 ** synonyms ***= Trigonomartus Petrunkevitch, 1913 ***= Phrynomartus Petrunkevitch, 1945a **'' Aphantomartus areolatus'' Pocock, 1911 – Early/Late Carboniferous, Europe ***synonyms ****= ''Aphantomartus pococki'' Pruvost, 1912 ****= ''Trigonomartus dorlodoti'' Pruvost, 1930 ****= ''Eophrynus waechteri'' Guthörl, 1938 ****= ?''Trigonomartus pruvosti'' van der Heide, 1951 ****= ?''Brachylycosa manebachensis'' Müller, 1957 ** '' Aphantomartus ilfeldicus'' (Scharf, 1924) – Permian, Germany ** '' Aphantomartus pustulatus'' (Scudder, 1884) – Late Carboniferous, Europe, North America ***synonyms ****= ?''Kreischeria villeti'' Pruvost, 1912 ****= ''Cleptomartus plötzensis'' Simon, 1971 ; Kreischeriidae Haase, 1890 * '' Anzinia'' Petrunkevitch, 1953 ** '' Anzinia thevenini'' (Pruvost, 1919) – Late Carboniferous, France * '' Gondwanarache'' Pinto & Hünicken, 1980 ** '' Gondwanarache argentinensis'' Pinto & Hünicken, 1980 – Late Carboniferous, Argentina * '' Hemikreischeria'' Frič, 1904 ** '' Hemikreischeria geinitzi'' (Thevenin, 1902) – Late Carboniferous, France * '' Kreischeria'' Geinitz, 1882 ** '' Kreischeria wiedei'' Geinitz, 1882 – Late Carboniferous, Germany * '' Pseudokreischeria'' Petrunkevitch, 1953 ** '' Pseudokreischeria pococki'' (Gill, 1924) – Late Carboniferous, England ***synonym ****= ''Eophrynus varius'' Petrunkevitch, 1949 ; Eophrynidae Karsch, 1882 * synonym **= Hemiphrynidae Frič, 1904 * '' Eophrynus'' Woodward, 1871 ** '' Eophrynus prestvicii'' (Buckland, 1837) – Late Carboniferous, England ** '' Eophrynus udus'' Brauckmann, Koch & Kemper, 1985 – Late Carboniferous, Germany * '' Nyranytarbus'' Harvey & Selden, 1995 ** synonym ***''Hemiphrynus'' Frič, 1901 **'' Nyranytarbus hofmanni'' (Frič, 1901) – Late Carboniferous, Czech Republic ** '' Nyranytarbus longipes'' (Frič, 1901) – Late Carboniferous, Czech Republic * '' Petrovicia'' Frič, 1904 ** '' Petrovicia proditoria'' Frič, 1904 – Late Carboniferous, Czech Republic * '' Planomartus'' Petrunkevitch, 1953 ** '' Planomartus krejcii'' (Kušta, 1883) – Late Carboniferous, Czech Republic ***synonym ****= ''Anthracomartus affinis'' Kušta, 1885 * '' Pleophrynus'' Petrunkevitch, 1945a ** '' Pleophrynus verrucosus'' (Pocock, 1911) – Late Carboniferous, UK, United States ***synonym ****= ''Eophrynus warei'' Dix & Pringle, 1930 ****= ''Pleophrynus ensifer'' Petrunkevitch, 1945a ****= ''Eophrynus jugatus'' Ambrose & Romano, 1972 * '' Pocononia'' Petrunkevitch, 1953 ** '' Pocononia whitei'' (Ewing, 1930) – Early Carboniferous, United States * '' Somaspidion'' Jux, 1982 ** '' Somaspidion hammapheron'' Jux, 1982 * '' Stenotrogulus'' Frič, 1904 ** synonyms ***= ''Cyclotrogulus'' Frič, 1904 ***= ''Pseudoeophrynus'' Příbyl, 1958 **'' Stenotrogulus salmii'' (Stur, 1877) – Late Carboniferous, Czech Republic ***synonyms ****= ''Cyclotrogulus sturii'' Frič, 1904 on Hasse, 1890/small> ****= ''Pseudoeophrynus ostraviensis'' Příbyl, 1958 ;Family uncertain * '' Aenigmatarbus'' Poschmann, Dunlop, Bértoux & Galtier, 2016 **'' Aenigmatarbus rastelli'' Poschmann, Dunlop, Bértoux & Galtier, 2016 - Carboniferous, Graissessac, France *'' Namurotarbus'' Poschmann & Dunlop, 2010 **'' Namurotarbus roessleri'' (Dunlop & Brauckmann, 2006) - Carboniferous, Hagen-Vorhalle ***synonyms ****= ''Archaeomartus roessleri'' Dunlop & Brauckmann, 2006 *'' Permotarbus'' Dunlop & Rößler, 2013 **'' Permotarbus schuberti'' Dunlop & Rößler, 2013 Permian, Chemnitz *'' Tynecotarbus'' Hradská & Dunlop, 2013 **'' Tynecotarbus tichaveki'' Hradská & Dunlop, 2013 - Carboniferous, Týnec ;''

incertae sedis ' () or ''problematica'' is a term used for a taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertain ...

'' * '' Anthracophrynus'' Andrée, 1913 ** '' Anthracophrynus tuberculatus'' Andrée, 1913 – Late Carboniferous, Germany * Areomartus Petrunkevitch, 1913 **'' Areomartus ovatus'' Petrunkevitch, 1913 - Carboniferous, West Virginia *‘''Eophrynus''’ ''scharfi'' Scharf, 1924 – Early Permian, Germany *'' Aphantomartus'' Pocock, 1911 **'' Aphantomartus woodruffi'' (Scudder, 1893) - Carboniferous, Rhode Island ;''

nomina dubia In binomial nomenclature, a ''nomen dubium'' (Latin for "doubtful name", plural ''nomina dubia'') is a scientific name that is of unknown or doubtful application. Zoology In case of a ''nomen dubium'' it may be impossible to determine whether a s ...

'' * ''Anthracomartus buchi'' (Goldenberg, 1873) – Late Carboniferous, Germany * ''Anthracomartus hageni'' (Goldenberg, 1873) – Late Carboniferous, Germany * ''Elaverimartus pococki'' Petrunkevitch, 1953 – Late Carboniferous, Scotland * ''Eurymartus latus'' Matthew, 1895 – Late Carboniferous, Canada * ''?Eurymartus spinulosus'' Matthew, 1895 – Late Carboniferous, Canada

References

{{Taxonbar, from=Q19107 Arachnid orders Prehistoric arthropod orders Silurian arachnids Devonian arachnids Carboniferous arachnids Permian arachnids Devonian arthropods of North America Carboniferous arthropods of North America Permian arthropods of North America Carboniferous arthropods of Europe Devonian arthropods of Europe Permian arthropods of Europe Silurian arthropods of Europe Silurian first appearances Cisuralian extinctions Taxa named by Alexander Petrunkevitch