''Burmesarchaea'' is a diverse extinct genus of

spider Spiders (order (biology), order Araneae) are air-breathing arthropods that have eight limbs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude spider silk, silk. They are the largest order of arachnids and ran ...

s, placed 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 ...

. The type species ''Burmesarchaea grimaldii'' was first described in 2003 and least 13 more species have been assigned to the genus. The genus has been exclusively found in

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

Burmese amber Burmese amber, also known as Burmite or Kachin amber, is amber from the Hukawng Valley in northern Myanmar. The amber is dated to around 100 million years ago, during the latest Albian to earliest Cenomanian ages of the mid-Cretaceous period. Th ...

, which is dated to 99 million years ago.

Description

''Burmesarchaea grimaldii'' is only known from a single male specimen preserved in amber. It is a small spider, with a body length of just under . Characteristic of the family Archaeidae, the head region is raised up from the thorax, although without the distinctive "neck" found in other genera in the family. It is presumed to have eight eyes (the posterior median eye is not visible); the anterior median eye is the largest. The

chelicerae The chelicerae () are the arthropod mouthparts, 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 ...

are long relative to the body at about , and project forward at about 45 degrees. The longest leg, the first, is long; the shortest, the third, is long. All the legs are without spines. The

pedipalp Pedipalps (commonly shortened to palps or palpi) are the secondary pair of forward appendages among Chelicerata, chelicerates – a group of arthropods including spiders, scorpions, horseshoe crabs, and sea spiders. The pedipalps are lateral to ...

has a large, rounded

bulb In botany, a bulb is a short underground stem with fleshy leaves or leaf basesBell, A.D. 1997. ''Plant form: an illustrated guide to flowering plant morphology''. Oxford University Press, Oxford, U.K. that function as food storage organs duri ...

with a spoon-shaped embolus and bent tegular apophysis.

Taxonomy

A fossil spider, the type species holotype from Burmese amber, was first described by David Penny in 2003 as ''Afrarchaea grimaldii''. The species name ''grimaldii'' honours David Grimaldi of the

American Museum of Natural History The American Museum of Natural History (AMNH) is a natural history museum on the Upper West Side of Manhattan in New York City. Located in Theodore Roosevelt Park, across the street from Central Park, the museum complex comprises 21 interconn ...

for his contributions to the study of amber and for assistance with the specimen. In 2008, J. Wunderlich transferred ''A. grimaldii'' and '' Lacunauchenius speciosus'' to his newly erected genus, ''Burmesarchaea''.

Species

*''B. alissa'' Wunderlich, 2017 *''B. caudata'' Wunderlich, 2017 *''B. crassicaput'' Wunderlich, 2017 *''B. crassichelae'' Wunderlich, 2017 *''B. gibber'' Wunderlich, 2017 *''B. gibberoides'' Wunderlich, 2017 *''B. gibbosa'' Wunderlich, 2017 *''B. grimaldii'' (Penney, 2003) *''B. longicollum'' Wunderlich, 2017 *''B. propinqua'' Wunderlich, 2017 *''B. pseudogibber'' Wunderlich, 2017 *''B. pustulata'' Wunderlich, 2017 *''B. quadrata'' Wunderlich, 2017 *''B. speciosa'' (Wunderlich, 2008)

References

{{Taxonbar, from=Q2928525 Archaeidae Extinct arachnids Araneomorphae genera Burmese amber Fossils of Myanmar Fossil taxa described in 2003 Spiders of Asia