Wednesday, September 12, 2018

[Arachnida • 2018] Chinja gen. nov. • A New Genus of Spider (Araneae, Zoropsidae) from the Eastern Arc Mountains of Tanzania; Chinja chinja & C. scharffi


 Chinja scharffi
 Polotow & Griswold, 2018


Abstract
The new zoropsid spider genus Chinja Polotow & Griswold is diagnosed and described and the following two new species are described: Chinja chinja sp. nov. and Cscharffi sp. nov. The species were collected in the Eastern Arc Mountains of Tanzania and appear to be endemic to this region. The genus belongs to the oval-calamistrum clade (OC Clade), which also includes Dionycha and Lycosoidea. Based on the synapomorphies and diagnostic characters of members of the OC Clade, Chinja is considered a member of Zoropsidae, although without a clear subfamily placement due to insufficient data. Males of Chinja can be distinguished from other Zoropsidae by a straight PER, by lacking a tibial crack, by having a male palpal cymbium with a retrobasal process and the male palpal tibia with an RTA and a retromedian cluster of stout setae. Females have a divided cribellum with cribellar spigots evenly arranged, and the epigynum with the median plate broad and laterally procurved into hooks, and the lateral lobes each with a wide tooth. The following set of characters can be also helpful to identify the genus: presence of a third tarsal claw, absence of claw tufts and presence of a cribellum and calamistrum.

Keywords: Araneae, Africa, Eastern Arc Mountain Hotspot, Lycosoidea, OC Clade, new species


TAXONOMY 
ZOROPSIDAE BERTKAU, 1882

 Type genus: Zoropsis Simon, 1878: 327
(Type species by monotypy: Dolomedes spinimanus Dufour, 1820)

Composition. The living Zoropsidae include 26 genera and 180 species (World Spider Catalog 2018). Wunderlich (2017) recognizes four genera and 16 Palaeogene, extinct species from Bitterfeld and Baltic amber. 

Distribution. Worldwide. 


Chinja Polotow & Griswold, new genus 

Etymology. Name is an arbitrary combination of letters and is to be considered feminine in gender. 

Type species. Chinja chinja sp. nov., here designated. 
Composition. Two species: Chinja chinja sp. nov. and C. scharffi sp. nov. 

Natural history. All species have been collected in the leaf litter and on the soil surface of closed-canopy, moist forest. Although the cribellum and calamistrum appear functional, we have no data on the web, if any. 

Distribution. Endemic to the Eastern Arc Mountains of Tanzania.



 Chinja chinja sp. nov

Etymology. The species epithet is an arbitrary combination of letters.

Natural history. This species occurs in the leaf litter and on the soil surface of closed-canopy, moist forest. 

Distribution. Eastern Usambara Mountains, Tanzania.


Chinja scharffi sp. nov., holotype male, CASENT9006146, dorsal.
Illustration by Jenny Speckels.

Chinja scharffi sp. nov.

Etymology. The species epithet is a patronym in honor of Nikolaj Scharff, a leader in biodiversity studies and conservation in the Eastern Arc Biotic Hotpot of Tanzania and collector of this and many other endemic Eastern Arc species.

Natural history. This species occurs in the leaf litter and on the soil surface of closed-canopy, moist forest, and is found at low (700 m) to high (1850 m) elevations.

 Distribution. Uzungwa and Uluguru Mountains, Tanzania. 


Daniele Polotow and Charles Griswold. 2018. Chinja, A New Genus of Spider from the Eastern Arc Mountains of Tanzania (Araneae, Zoropsidae).  Zootaxa. 4472(3); 545–562. DOI: 10.11646/zootaxa.4472.3.7