Spiders of this genus are fairly large, with females of some Chinese species ranging from 1 to 3 centimetres (0.4 to 1.2in) in body length. Males are smaller, sometimes only half that length.[4] Macrothelids can be distinguished from other mygalomorph spiders by their larger posterior sigillae on the sternum, and the arrangement of the rows of teeth on the margin of the chelicerae: larger front-facing margin and smaller rear-facing.[5]
These spiders build tube-webs or funnel-webs under rocks or logs, or in crevices in the ground.[4]
The genus Macrothele was erected by Anton Ausserer in 1871, with the type species being Macrothele calpeiana, formerly Mygale calpeiana.[1][citation needed] Ausserer placed the genus in the then very broadly defined family Theraphosidae. It was later placed in the Dipluridae and the Hexathelidae before being transferred to the Macrothelidae in 2018.[1] A molecular phylogenetic study in 2018 suggested that Macrothele was a distinct, early diverging lineage within the Mygalomorphae. Accordingly, Simon's subfamily Macrothelinae was elevated to the family Macrothelidae. There is some doubt if the western and eastern species should be grouped in the same genus.[6]
The following cladogram shows the possible relationship of Macrothele to related taxa:[5]
Ausserer, A. (1871). "Beiträge zur Kenntniss der Arachniden-Familie der Territelariae Thorell (Mygalidae Autor)". Verhandlungen der Kaiserlich-Königlichen Zoologisch-Botanischen Gesellschaft in Wien. 21: 117–224.