Face-sized tarantula lives in trees in Sri Lanka

Face-sized tarantula: With a leg span of up to 8 inches across, the Poecilotheria rajaei, is one of the larger species of tarantula.

Wired reports on what may be a new species of tarantula in Northern Sri Lanka, and it's unlikely to be appearing on the island nation's tourism materials any time soon.

Writer Nadia Drake describes the tree-dwelling Poecilotheria rajaei  as "about the size of your face" – the human face apparently being a standard metric for tarantula sizes – and notes that it has a pink band on its underside. 

The spider was first discovered in 2009, by Ranil Nanayakkara, co-founder of Sri Lanka’s Biodiversity Education and Research.

“They are quite rare,” Nanayakkara told Wired. “They prefer well-established old trees, but due to deforestation the number have dwindled, and due to lack of suitable habitat they enter old buildings.”

As huge as P. rajaei is, it's not actually the world's biggest tarantula. That distinction goes to Theraphosa blondi, the Goliath birdeater, a burrowing spider native to the rainforests of northern South America. These spiders have a leg span of up to 12 inches – or 1.5 faces.

The Goliath birdeater is the world's second largest spider by leg span, and might be the largest by mass. The cave-dwelling giant huntsman spider, Heteropoda maxima, discovered in Laos in 2001, has a leg span that is slightly longer than that of the birdeater.

For what it's worth, the world's smallest spider is the Patu marplesi, a species native to Western Samoa. According to the Guinness Book of World records, It measures 0.017 inches. You could fit about 470 of them on your face, if you felt so inclined.   

But back to the Sri Lankan tarantula. Researchers are not completely certain that it represents a new species. Wired's Drake spoke with Robert Raven, an arachnologist at the Queensland Museum in Australia, who suspects that it very well could be a local variant of a related species. She notes that the spider closely resembles Poecilotheria regalis, a species native to the Indian mainland. We won't know until DNA samples are taken.

Ms. Drake writes that the spider's discoverer "hints that he’s got several more potential new tarantulas up his sleeve, awaiting review." Let's hope that she didn't mean that literally.