More on the Mesopotamian-Yungas disjunction in subtropical and temperate Argentina: Bioclimatic distribution models of the harvestman Discocyrtus dilatatus (Opiliones: Gonyleptidae)

Changes in Species Richness and Composition of Tiger Moths (Lepidoptera: Erebidae: Arctiinae) among Three Neotropical Ecoregions

“…During the climatic fluctuations of the Pleistocene, Yungas, Paraná and Chaco were merged due to climatic vegetational fluctuations and some modern remnant patches that act as relict connections, allowing some species to expand their distributional ranges [ 70 ]. This hypothesis is used to explain the distribution pattern of some marsupials, birds and harvestmen [ 71 – 73 ]. On the other hand, the spatial proximity of Yungas to Chaco habitats could explain this closer association.…”

The disjunct pattern of the Neotropical harvestman Discocyrtus dilatatus (Gonyleptidae) explained by climate-driven range shifts in the Quaternary: Paleodistributional and molecular evidence

“…The original dataset, detailed in [ 27 ], included 85 georeferenced unique localities ( Fig 1 ). For this analysis, the reliability of pre-1950 records was revisited, retaining only those validated by recent collections, at least from surrounding localities; this resulted in three points from Paraguay being excluded ( Fig 1 ).…”

“…Nores’ hypothesis seemed pertinent to explain the findings in NWA of disjunct populations of wide-ranged Mesopotamian and Paranense harvestmen: the gonyleptids Discocyrtus dilatatus Sørensen, 1884 ( Fig 1 ), D . prospicuus (Holmberg, 1876) and Geraeocormobius sylvarum Holmberg, 1887, and the cosmetid Gryne orensis (Sørensen, 1879) [ 22 – 27 ]. As widely recognized, harvestmen are heavily dependent on humid environments [ 23 , 28 – 30 ]; consequently, the 450 to 650 km gap of inhospitable Dry Chaco represents an insurmountable barrier to active dispersal for such low-vagility organisms, at least under current conditions.…”

“…In any case, the existence of a hypothetical trans-Chaco corridor was never formally tested for a Mesopotamian harvestman. Given its known range ( Fig 1 ), Discocyrtus dilatatus , a kind of ‘flagship species’ for the disjunction case [ 23 , 27 ], appears particularly well-suited to test the paleobridge hypothesis. In this paper, this question is tackled by means of two independent, complementary approaches, as detailed below.…”

“…Some Mesopotamian species have been the subject of spatial analysis through SDM, but those analyses were based on current climate alone ( Gryne orensis [ 26 ], Discocyrtus testudineus (Holmberg, 1876) [ 38 ], D . dilatatus [ 27 ]). Provided that paleoclimatic information is available, climate-based SDMs are feasible to be projected onto past chronologies to estimate paleodistributions [ 12 ; 39 – 42 ].…”