Reconstructing the distribution of Chacoan biota from current and past evidence: the case of the southern three-banded armadillo Tolypeutes matacus (Desmarest, 1804)

Abstract

Climatic oscillations acted as an essential factor in molding the distribution and composition of Neotropical biota. However, their effects on the South American Chaco are still poorly known. In this work, we present an updated collection of records of one of its flagship species, Tolypeutes matacus. We analyze the species' range dynamics in current and past scenarios to unveil the effects of past changes over the Chacoan biota. We construct three niches, one with current data (current niche), the other using Pleistocenic occurrence data and predictors from the Last Glacial Maximum (glacial niche), and the last one combining current and Pleistocene data to generate a multitemporal niche. Niches were projected to Current, Mid-Holocene, Last Glacial Maximum, and Last Interglacial scenarios. We obtain 398 records for the species, corresponding to current, historical, Holocene, and Pleistocene records. Current distribution occurs mainly in the currently Chaco region. For current niche reconstructions, suitable areas were smaller than those found nowadays, mainly during the Last Interglacial and Last Glacial Maximum. Holocene reconstruction recovers a distribution of suitable areas pretty similar to the present times. In contrast, glacial niche projection shows higher suitability values in the Pampean Region in all periods analyzed. Multitemporal niche projections showed similar results to those obtained from the current niche projections. Climatic oscillations seem to have significantly impacted the distribution of the species, generating retractions during past times and a period of range stability since the Holocene. Differences between niche projections suggest that Pampean populations may have evolved in different conditions than those from the Chacoan region.