Context:

• Scientists rediscovered after 150 years a rare species of spider, which was believed have become extinct, from the Wayanad Wildlife Sanctuary (WWS) located in the Western Ghats region of Kerala.
• The inventory of a species of spider from Pariej Lake in Gujarat in 1868. But subsequently it had vanished.

Other facts:

• The spider belonged to the family of jumping spiders (Salticidae) and scientifically named as Chrysilla volupes.
• A species that is not seen for more than 100 years is considered extinct. So this finding underlines the urgent need to conduct more exploratory survey of faunal diversity in India, a mega-diverse country.

Wayanad Wildlife Sanctuary:

• An animal sanctuary in Wayanad, Kerala, India. 
• In particular, peafowl tend to be very common in the area. Wayanad Wildlife Sanctuary is the second largest wildlife sanctuary in Kerala.
• The sanctuary is now an integral part of the Nilgiri Biosphere Reserve.
• It is bounded by protected area network of Nagarhole and Bandipur of Karnataka in the northeast, and on the southeast by Mudumalai of Tamil Nadu.
• The wildlife sanctuary comes under Protect Elephant and one can spot herd of elephants roaming in the area. 

Source: TH & Wiki