New insights on male palpal bulb morphology in Cymbiapophysa Gabriel & Sherwood, 2020, with four new species from Ecuador (Araneae: Theraphosidae).

Four new species of Cymbiapophysa Gabriel & Sherwood, 2020 from north-western Ecuador are described based on unique combinations of male palpal bulb and female spermathecae morphology: C. ashily sp. nov., C. matildeae sp. nov., C. otongachi sp. nov., and C. yumbos sp. nov. An updated diagnosis, key to species, and comparative plate of the male palpal bulb of previously known species, with relabelling of some keels as necessary, and evidence of a subapical keel in Cymbiapophysa species, are presented. Additionally, we provide further commentaries about cymbial morphology and male palpal bulb structures, and two possible hypotheses related to the origin of accessory keels. [ABSTRACT FROM AUTHOR]