[2] A second putative species, Mongolarachne chaoyangensis, was described in 2019,[4] but it was subsequently shown to be a forgery based on a fossil crayfish.

The individuals are preserved as compression fossils in a pale grey finely laminated sedimentary tuff.

The type specimens is currently preserved in the Key Lab of Insect Evolution & Environmental Changes collections housed in the Capital Normal University, located in Beijing, China.

[2] The genus name Mongolarachne is derived from (Inner) Mongolia, where the fossils were found, and the Latin arachne meaning "spider".

The oldest recognized member of the family Nephilidae is the Cretaceous species Cretaraneus vilaltae of Spain.

The authors considered it most likely that M. jurassica is a stem-orbicularian, more distantly related to the group Araneoidea (including nephilids) than deinopids and uloborids are.

The feature of a gaiter on the third tibia is found only in modern Nephila and, according to the original authors of description of M. jurassica, its presence along with the large size indicated the species was part of the genus.