An integrative approach unveils speciation within the threatened spider Calathotarsus simoni (Araneae: Mygalomorhpae: Migidae

FERRETTI,NELSON, ALDA GONZALEZ, MIQUEL ARNEDO

SYSTEMATICS AND BIODIVERSITY

CAMBRIDGE UNIV PRESS

Lugar: Cambridge; Año: 2019 p. 1 - 19

1477-2000

The mygalomorph trapdoor spider family Migidae displays a quintessential Gondwanan distribution, including species inAustralia, Africa, Madagascar, New Zealand, New Caledonia, and the southern cone of South America. The Argentineanfauna consists of a single species, Calathotarsus simoni Schiapelli & Gerschman, 1975, with a highly localizeddistribution range restricted to two mountain ranges in the southern Buenos Aires province, central Argentina. The recentdiscovery of specimens from new localities including adult males and females revealed morphological differences.Similarly, a molecular phylogenetic analysis using mitochondrial and nuclear markers distinguished two main lineageswithin C. simoni, showing genetic divergence in the levels reported for other species within the family. The two lineagescorresponded to each of the two main ranges inhabited by the species and matched the morphological differencesobserved. Finally, an ecological niche modelling analysis revealed significant ecological differences between the lineagesinhabiting the two mountain ranges. Based on integration of all the evidence, the new species Calathotarsus fangioi sp.nov. is described. The new species is circumscribed to the easternmost mountain range of Tandilia, while the distributionC. simoni is re-delimited to include only the western range of Ventania. Both species are diagnosed, described, andillustrated. This new species description and the conservation status for these remarkable spiders are further discussed.