TRACING EVOLUTIONARY PARALLELISMS BETWEEN GLYPTODONTINAE AND DASYPODINAE (XENARTHRA, CINGULATA).

BARASOAIN, D.; CUADRELLI, F.; ZURITA, A. E; AHUMADA, S.

Salta

Simposio; Reunion de comunicaciones de la APA; 2022

APA

Glyptodontinae constitutes the clade with the greatest latitudinal distribution of glyptodonts,including the genera Boreostemma (middle Miocene), Glyptotherium (Late Pliocene-LatePleistocene), and Glyptodon (Middle Pleistocene-Late Pleistocene). In turn, Dasypodinae is a cladeof “armadillos” including the genera Plesiodasypus (middle Miocene), Anadasypus (middle-LateMiocene), Pliodasypus (Pliocene), Propraopus (Pleistocene-Early Holocene) and Dasypus (LatePliocene-current). Both lineages have different morphologies and ecological niches. While theGlyptodontinae are large-sized, (ca. 450-800 kg in the terminal species), and usually interpreted asgeneralist grazers, the Dasypodinae are medium-sized armadillos (ca. 8-15 kg in Dasypus species)interpreted as generalist to mainly insectivore forms. Despite these ecological and morphologicaldifferences, the evolutionary/paleobiogeographic history of Glyptodontinae and Dasypodinae showsmarked similarities: 1) a low latitudinal origin in South America (earliest records from La Venta,Colombia); 2) they respectively represent the sister-group of the remaining diversity of glyptodontsand “armadillos”, implying an early divergence; 3) they have a relatively high abundance and widedistribution (ca. 35°N-38°S) but a low diversity compared to other lineages; 4) they represent theonly groups of their families to have crossed and diversified in North America during the GABI(e.g., Glyptotherium and Dasypus). From a palaeoecological viewpoint, the environments innorthern-most South America during the Miocene were warm and humid. These conditions arecommonly related to lineages with great distribution capacities, giving place to highly plasticderived species, while conserving representatives in their ancestral area (e.g., Glyptotherium cf. G.cylindricum from the late Pleistocene or Dasypus spp. from Holocene, both from northern-mostSouth America). The arrival of Glyptodontinae (“Glyptodontidium”) and Dasypodinae to highlatitudes in South America is coincident with the maximum expression of the “Age of the SouthernPlains” (Late Miocene-Pliocene). Regarding North America, both reached similar latitudes althoughunder different climatic conditions. The northernmost record of Glyptodontinae (Glyptotherium)coincides with a warm period during the Late Pliocene. Later on, during the Pleistocene, the climatebecame progressively drier, causing their distributional retraction. Contrary, the first presence ofDasypodinae (Dasypus) for these latitudes is concordant with the drought events that caused theretraction of glyptodonts. In summary, the lower diversification, together with a high dispersalpotential, has been previously reported for other groups of mammals with intertropical origin (e.g.,Rodentia). In this scenario, a common temporal and geographic origin between Dasypodinae andGlytodontinae could explain the parallelism in their paleobiogeographic history. This pattern has notbeen previously reported for other Cingulata lineages.