- Trapdoor spider (Gaius villosus)
- 43 year(s)
- Australia ()
The oldest known spider was a female Gaius villosus – a type of trapdoor spider endemic to Australia – known as "Number 16" ("#16"), which lived in North Bungulla Reserve near Tammin in south-western Australia. As described in an article published in the journal Pacific Conservation Biology, on 19 April 2018, the specimen was first documented in March 1974 by arachnologist Barbara York Main (Australia) and was last seen alive circa April 2016, which would put her minimum age at 43 years old.
This surpasses the current holder by at least 15 years: a female bird-eating spider (family Theraphosidae) collected in Mexico in 1935 was estimated to have been 26–28 years old when she died.
"Number 16" is suspected to have been killed by a parasitic wasp, after the lid of her burrow showed evidence of being pierced by a wasp's stinger, as documented on 31 October 2016.