Dugesia (Tricladida, Platyhelminthes) Cox1, 18S, 28S, ITS-1, DUNUC3, DUNUC5 datasets for worldwide biogeographic study

Aim: Freshwater planarians may have a wide geographic range despite their
assumed low vagility. Found across four continents, Dugesia may have
either an ancient origin on a large paleo landmass, followed by
colonisation in different regions before continental fragmentation, or a
more recent origin and subsequent transoceanic dispersal. We seek to
resolve between these two hypotheses. Location: Africa, Eurasia, and
Australasia Taxon: Genus Dugesia (Platyhelminthes: Tricladida: Dugesiidae)
Methods: We used data from the sequencing of six gene fragments and
comprehensive taxonomic sampling of Dugesia from across its distribution
range to reconstruct the phylogeny of this genus using maximum likelihood
and bayesian inference methods. We conducted two phylogenetic dating
analyses using Platyhelminthes fossils and palaeogeological events. Basing
on the time-calibrated molecular phylogenetic framework we evaluated the
contribution of vicariance and dispersal to the biogeographic evolution of
Dugesia. By reconstructing the ancestral areas and present-day potential
distribution using BioGeoBEARS and niche modelling, we elucidated the
biogeographic history of the genus. Results: The present-day distribution
of Dugesia is a result of different vicariance and dispersal events.
However, we also found evidence of transoceanic dispersal. Consistent with
previous hypotheses, Dugesia dates to the Upper Jurassic in the
Afro-Malagasy Gondwana region. We unveiled a novel biogeographic scenario
for the genus, involving multiple events of colonisation in Eurasia from
continental Africa via at least three dispersal routes. Main conclusions:
Dugesia is an ancient genus having reached its present distribution
through a complex history of dispersal and vicariant events following its
origin in southern Gondwana. Despite the low vagility of Dugesia, we found
evidence of their overseas dispersal.