''Sason robustum'' is a species of barychelid trapdoor

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. It is only found in southern

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...

Sri Lanka Sri Lanka (, ; si, ශ්‍රී ලංකා, Śrī Laṅkā, translit-std=ISO (); ta, இலங்கை, Ilaṅkai, translit-std=ISO ()), formerly known as Ceylon and officially the Democratic Socialist Republic of Sri Lanka, is an ...

and the

Seychelles Seychelles (, ; ), officially the Republic of Seychelles (french: link=no, République des Seychelles; Creole: ''La Repiblik Sesel''), is an archipelagic state consisting of 115 islands in the Indian Ocean. Its capital and largest city, V ...

. Males are about 9 mm long, females almost 11 mm.

Distinguishing features

''Sason robustum'' is characterized by absence of teeth on the claws; cuspules present on

maxilla The maxilla (plural: ''maxillae'' ) in vertebrates is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The t ...

e and labium; rastellum absent; the apex of the first tibia with a single stout prolateral spine; and 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 ...

spherical with a tapering

embolus An embolus (; plural emboli; from the Greek ἔμβολος "wedge", "plug") is an unattached mass that travels through the bloodstream and is capable of creating blockages. When an embolus occludes a blood vessel, it is called an embolism or emb ...

Taxonomy

''Sason robustum'' was first described by

Octavius Pickard-Cambridge Octavius Pickard-Cambridge Fellow of the Royal Society, FRS (3 November 1828 – 9 March 1917) was an England, English clergyman and zoologist. He was a keen arachnologist who described and named more than 900 species of spider. Life and wor ...

in 1883. He placed it in a new genus ''Sarpedon''. However this name had already been used for a beetle, so in 1887,

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, ...

put forward the replacement genus name, ''Sason''.

References

Barychelidae Spiders of Asia Spiders of Africa Spiders described in 1883 {{barychelidae-stub