Arthrolycosidae is an extinct family of

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, possibly

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 ...

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 ...

s placed in the family were found in the Carboniferous to

Permian The Permian ( ) is a geologic period and System (stratigraphy), 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 ...

, . They were considered by

Alexander Petrunkevitch Alexander Ivanovitch Petrunkevitch ( Russian: Александр Иванович Петрункевич, December 22, 1875 in Plysky near Kyiv, now Ukraine – March 9, 1964 in New Haven) was an eminent Russian arachnologist of his time. ...

to be "mesotheles", i.e. placed in the spider suborder

Mesothelae The Mesothelae are a suborder of spiders (order Araneae) 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 ...

. However, Paul A. Selden has stated they only have "the general appearance of spiders", with 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 ...

e), but no definite spinnerets. At least some of the specimens placed in the family in the genus ''Arthrolycosa'' are considered to be spiders, whereas ''Eocteniza'' is "rather problematic as a spider".

Genera

Genera placed in the Arthrolycosidae are shown below, together with the location of the fossils. * †'' Arthrolycosa'' Harger, 1874 – United States ( Mazon Creek), Ukraine, Russia * †'' Eocteniza'' Pocock, 1911 – England (

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 ...

)

References

Paleozoic arachnids † {{paleo-spider-stub