''Acanthogonatus mulchen'' is a mygalomorph spider of

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...

, named after its type locality: Alto Caledonia, east of Mulchén, Region VIII ( Bío Bío Region).Goloboff, Pablo A. "A revision of the South American spiders of the family Nemesiidae (Araneae, Mygalomorphae). Part 1, Species from Peru, Chile, Argentina, and Uruguay. Bulletin of the AMNH; no. 224." (1995). It is recognised by the long, narrow sternum. It differs from '' A. tolhuaca'' in the spermathecae having a less pronounced notch and the glandular areas on each side joining in the middle. It is larger (''A. mulchen'' has a

cephalothorax 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 ...

length of up to , and a total length of ) and differs from '' A. brunneus'' by its uniformly colored abdomen.

Description

*Female: total length ; cephalothorax length , width ; cephalic region length , width ;

fovea Fovea () (Latin for "pit"; plural foveae ) is a term in anatomy. It refers to a pit or depression in a structure. Human anatomy *Fovea centralis of the retina * Fovea buccalis or Dimple * Fovea of the femoral head * Trochlear fovea of the fr ...

width ; medial ocular quadrangle length , width ; labium length , width ; sternum length , width . Its cephalic region is wide but low, while its fovea s straight to procurved with recurved ends, containing no posterior notch. Its labium possesses 2 cuspules. A serrula is present as a small patch of teeth only on the anterior face of the lobe. Its sternal sigilla is deep and long. Chelicerae: rastellum is absent. The entire spider is a uniform blackish-reddish-brown colour, except for one lighter spot in front of the

abdomen The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the torso. ...

. Juveniles have a similar color, but lighter, with diagonal lines of pale dots on the dorsum of their abdomen.

Distribution

Only in its type locality. It is found in densely

silk Silk is a natural protein fiber, some forms of which can be woven into textiles. The protein fiber of silk is composed mainly of fibroin and is produced by certain insect larvae to form cocoons. The best-known silk is obtained from the coc ...

-lined burrows, between wide, which originate from under stones or at the base of trees. The burrow's mouth is funnel-like, with white silk extending so as to form a sort of collar.

References

External links

*
ADW entry
* {{Taxonbar, from=Q2328060 Pycnothelidae Spiders of South America Spiders described in 1995 Endemic fauna of Chile