Researchers have described five new spider species that were hiding out in the dark of Southeast China.

The new critters are armored spiders, which are named for a tough pattern of plates covering their abdomen, a Pensoft news release reported. The plates strongly resemble body armor.

The name armored spiders refers to the family Tetrablemmidae.

"Distinguished by their peculiar armor-like abdominal pattern, these tropical and subtropical spiders are mainly collected from litter and soil, but like the newly described species some live in caves," the news release reported.

Some cave and soil species have showed certain adaptive traits such as loss of eyes. The genus Tetrablemma, which encompasses one of the newly-discovered species, is characterized by having only four eyes.

All of the new species were found in the South China Karst, which spans the provinces of Guangxi, Guizhou, and Yunnan and is a UNESCO World Heritage Site. Both the landscape and biodiversity of the region is rich and unique.

 "[The South China Karst] is unrivalled in terms of the diversity of its karst features and landscapes," UNESCO stated, the news release reported.

Researchers from the Chinese Academy of Sciences, led by Professor Shuqiang LI, have explored over 2,000 caves and reported several hundred new spider species.

The team's research has caused the number of known spiders in the region to jump from 2,300 to 4,300 over the past decade.

"A new genus and five new species belonging to the family Tetrablemmidae are described from caves in Southwest China, i.e., Sinammaoxycera, Singaporemma banxiaoensis, Singaporemma wulongensis, Tetrablemma ziyaoensis, andTetrablemma menglaensis, The following new combination is proposed: Sinamma sanya (Lin & Li, 2010), ex. Shearella Lehtinen, 1981. The relationships of the Sinamma with other genera are discussed. Diagnoses and illustrations for all new taxa are given," the abstract of the paper, published in the journal Zoo Keys reported.