Brachythele keithi Chamberlin, 1916

Drolshagen, Bastian & Bäckstam, Christian M., 2021, A taxonomic review of the mygalomorph spider genus Linothele Karsch, 1879 (Araneae, Dipluridae), Zoosystema 43 (10), pp. 163-196 : 191

Brachythele keithi Chamberlin, 1916 comb. rev. nomen dubium

Brachythele keithi Chamberlin, 1916: 204 , pl. 7, fig. 11. comb. rev.

Linothele keithi – Goloboff 1995: 95.

TYPE MATERIAL. — Holotype. Peru • indet.; Huadquiña ; 5000 ft a.s.l.; 1911; H. W. Foote leg.; MCZ 15491 ( RVC 147 ) examined.

REMARKS

Chamberlin (1916) proposed B. keithi based on a single specimen. He noted the labium to be much wider than long for B. keithi and Diplura monticolens . In the latter, we observed a more subquadrate labium. According to Chamberlin (1916) legs II and IV are missing, but tarsal scopulae are “dense, extending to base; none divided by a setose line or band.” Goloboff (1995) mentioned the holotype to be in extremely poor condition (“reduced to a series of loose fragments”) and tentatively transferred the species to Linothele , due to the “loose fragments of spinnerets accompanying the specimen, which appear to have corresponded to long spinnerets.” Chamberlin (1916) provided measurements for the cephalothorax and the spinnerets, of which he reported “the three joints subequal in length”. As the “cephalothorax” usually includes the chelicerae and the opisthosoma may vary in size, we have to agree the spinnerets seem to have been elongated. Chamberlin (1916) explicitly mentioned “conspicuously curved” tarsi for Diplura monticolens , but not so for Brachythele keithi . Goloboff (1995) further mentioned only 10 maxillary cuspules and “the epigastrium dissected and at least some parts of it placed in a separate microvial, but with no detectable spermathecae”. The largest intact part we were able to find in the vial of the holotype was a single maxilla with all cuspules broken off and no lyra visible. As none of the spinnerets, or leg tarsi was still intact, the transfer to Linothele by Goloboff (1995) cannot be confirmed with certainty. Despite its incorrect placement in Brachythele , the type is too fragmented to allow for a certain placement. As a result, Linothele keithi is transferred back to Brachythele due to original designation and Brachythele keithi comb. rev. is considered a nomen dubium.