Résumé
In the current paper we present an updated checklist of all the megadrile earthworms (Crassiclitellata: Annelida) in the world, and notes on the distribution of families worldwide.
Biogeographic responses to geological phenomena and continental drift, as well as to past and present climate and habitat distributions are the main factors determining the present distribution of earthworm families. A total of ca. 5,300 species and 330 subspecies belonging to 22 families (including one non-crassiclitellate family: Moniligastridae) are currently recognized worldwide, of which three families (Tritogeniidae and Kazimierzidae from Southern Africa and Arecoidae, a new family from Brazil described herein), 29 genera and close to 850 new taxa (including subspecies) were described in the last 20 years. Nonetheless, the large number of still undescribed species will likely increase this value to well over 8,000 species. Nine families are monospecific and/or monogeneric and have a mostly restricted distribution. On the other hand, more than 87 widespread cosmopolitan species have been catalogued, some of them with important invasive potential, belonging mainly to families Lumbricidae, Acanthodrilidae, Benhamiidae, Megascolecidae, Rhinodrilidae and Ocnerodrilidae. Taxonomic housekeeping was performed for the preoccupied Rhinodrilidae genus Tairona Righi 1984 -herein substituted by Taironina nom. nov., and Guarani camaqua Rodríguez & Lima 2007 was reinstated and removed from synonymy with Criodrilus lacuum Hoffmeister 1845, resulting in a wider definition of the Almidae family. Furthermore, Amynthas maximalis nom nov. is proposed herein as a substitution name for the preoccupied name Amynthas maximus Qiu & Dong 2019, and Arecoidae is proposed as a new monotypic family for the aquamegadrile species Areco reco Righi, Ayres & Bittencourt, 1978.