''Archaea'' is an extinct genus 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 in the family

Archaeidae Archaeidae, also known as assassin spiders and pelican spiders, is a spider family with about ninety described species in five genera. It contains small spiders, ranging from long, that prey exclusively on other spiders. They are unusual in that ...

. , four species are placed (or possibly placed) in the genus. All have been found preserved in

amber Amber is fossilized tree resin that has been appreciated for its color and natural beauty since Neolithic times. Much valued from antiquity to the present as a gemstone, amber is made into a variety of decorative objects."Amber" (2004). In ...

, either from the

Baltic Baltic may refer to: Peoples and languages * Baltic languages, a subfamily of Indo-European languages, including Lithuanian, Latvian and extinct Old Prussian *Balts (or Baltic peoples), ethnic groups speaking the Baltic languages and/or originati ...

Bitterfeld Bitterfeld () is a town in the district of Anhalt-Bitterfeld, Saxony-Anhalt, Germany. Since 1 July 2007 it has been part of the town of Bitterfeld-Wolfen. It is situated approximately 25 km south of Dessau, and 30 km northeast of Halle ( ...

, Germany. First described in 1854, ''Archaea'' species have a distinctive "neck" separating the head from the thorax, and very long

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 similarly ...

("jaws").

Description

In the genus ''Archaea'', the head is separated from the thorax by a deep fold, forming a "neck", so that the globular head appears to sit on the thorax. There are eight eyes, four on each side of the head, arranged in the shape of a

rhombus In plane Euclidean geometry, a rhombus (plural rhombi or rhombuses) is a quadrilateral whose four sides all have the same length. Another name is equilateral quadrilateral, since equilateral means that all of its sides are equal in length. The ...

, with the front eyes being the largest. The curved

are very long, longer than the head, with long, strong fangs. 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") and ...

s of the female are very small and thin, shorter than the chelicerae, the third and last segments being short, the latter needle-shaped. Those of the male are sturdier, the third segment being almost as long as the second, with the end segment bearing the

palpal bulb The two palpal bulbs – also known as palpal organs and genital bulbs – are the copulatory organs of a male spider. They are borne on the last segment of the pedipalps (the front "limbs" of a spider), giving the spider an appearance often descr ...

s. The thorax is relatively flat, narrower at the back than the front, and without thoracic grooves. The legs are long and thin. The first pair are the longest, the second somewhat longer than the fourth, the third being the shortest. The patellae and tarsi are short, without spines or bristles. Living members of the family Archaeidae are predators on other spiders (araneophageous); it is assumed that extinct members of the family had the same habits.

Taxonomy

The genus ''Archaea'' was erected in 1854 by C. L. Koch and G. C. Berendt, initially with three extinct species, all found in

from the

Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden and the North and Central European Plain. The sea stretches from 53°N to 66°N latitude and from ...

Saxony-Anhalt Saxony-Anhalt (german: Sachsen-Anhalt ; nds, Sassen-Anholt) is a state of Germany, bordering the states of Brandenburg, Saxony, Thuringia and Lower Saxony. It covers an area of and has a population of 2.18 million inhabitants, making it the ...

, Germany. It was then the only genus in the family Archaeidae. The first living species in the family was described in 1881 by O. Pickard-Cambridge. He placed it in the genus ''

Eriauchenius ''Eriauchenus'' is a genus of East African assassin spiders first described by O. Pickard-Cambridge in 1881. The genus name has been incorrectly spelt "''Eriauchenius''". Species , it contained twenty species, all found on Madagascar M ...

'' as '' E. workmani''. In 1895,

Eugène Simon Eugène Louis Simon (; 30 April 1848 – 17 November 1924) was a French naturalist who worked particularly on insects and spiders, but also on birds and plants. He is by far the most prolific spider taxonomist in history, describing over 4, ...

transferred this species to ''Archaea'' as ''Archaea workmani''. Other living species were placed in the genus later, but all are now considered to belong to different genera.

Species

*†?''Archaea bitterfeldensis'' Wunderlich, 2004 – Bitterfeld amber *†''Archaea compacta'' Wunderlich, 2004 – Baltic amber *†''Archaea paradoxa'' C.L. Koch & Berendt, 1854 (syn. ''Archaea laevigata'' C. L. Koch & Berendt, 1854, ''Archaea incompta'' Menge, 1854) (

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

) – Baltic amber *†''Archaea pougneti'' Simon, 1884 – Baltic amber Fossil species that have been placed in ''Archaea'' but are now placed elsewhere include: *†''Eroarchaea hyperoptica'' (Menge, 1854) = ''Archaea hyperoptica'' *†''Baltarchaea conica'' (Koch & Berendt 1854) = ''Archaea conica''

References

{{Taxonbar, from=Q2859968 Archaeidae Araneomorphae genera Extinct arachnids Fossil taxa described in 1854