INVESTIGADORES
ZURITA Alfredo Eduardo
capítulos de libros
Título:
An Introduction to Cingulate Evolution and Their Evolutionary History during the Great American Biotic Interchange: Biogeographical Clues from Venezuela
Autor/es:
CARLINI, A. A; ZURITA, A. E
Libro:
Urumaco: Palaentology of Venezuela
Editorial:
INDIANA UNIVERSITY PRESS
Referencias:
Lugar: Indiana, USA; Año: 2010; p. 233 - 255
Resumen:
As we
have discussed, the latest finds from northern Venezuela, along with a
reanalysis of the remains from Colombia, have brought about a new
interpretation of the evolutionary and biogeographical history of oneof the
major groups of glyptodonts, the Glyptodontinae (glyptodontines).This can be
summarized in the following points: 1 The morphological evidence suggests that
the glyptodonts from the Middle MiocenePliocene (ca. 125 Ma) of northernmost
South America (Colombia and Venezuela) do not belong to the subfamily
Propalaehoplophorinae, but actually represent the first stages in the
cladogenesis and later dispersion of the Glyptodontinae. 2 As a consequence of
this, the Propalaehoplophorinae are restricted to southernmost South America (Argentine
Patagonia). Likewise, the oldest records of Glyptodontinae are those from the
MiocenePliocene of the current territories of Colombia and Venezuela 3 The
oldest records of Glyptodontinae in southernmost South America, from the latest
Miocene and Pliocene of Argentine provinces Catamarca and Tucumán, partly
coincide with the peak of the Age of Southern Plains. This great latitudinal
extension of open savanna environments could have stimulated the southward
dispersal of these glyptodonts, by way of biogeographical corridors, as
proposed for other mammals. 4 At some point during the Pliocene, the
glyptodontines (probably together with the glyptatelines) passed onto Central
and North America, along with many other mammalian orders. At present, Glyptotherium
is the only genus recorded in those areas. 5 The presence of Glyptotherium
(cf. G. cylindricum) in the latest Pleistocene (ca. 14 ka) of
Venezuela (Falcón state) suggests an entry of these glyptodontines into South
America at some point during the Late Pleistocene, probably associated with
biogeographical corridors that could have formed during the glacial periods,
as proposed for other Cingulata (e.g., Pampatheriidae). 6 During the GABI, the
pampatheriids (like the glyptodontines) migrated into Central and North
America. The genus Holmesina, with the species H. septentrionalis, would
have evolved in these regions. 7 Later, this genus reentered South
America, following two routes: one para-Andean and another parallel to the
eastern coast. The cyclical climatic-environmental fluctuations that occurred
during the Pleistocene would have triggered speciation processes that gave rise
to endemic South American species. 8 Finally, and possibly during the Early
PleistoceneMiddle Pleistocene lapse, another genus (Pampatherium) would
have migrated towardNorth America, originating the species Pampatherium
mexicanum. 10 Later, this genus reentered South America, following two
routes: one para-Andean and another parallel to the eastern coast. The cyclical
climatic-environmental fluctuations that occurred during the Pleistocene would
have triggered speciation processes that gave rise to endemic South American
species. 11 Finally, and possibly during the Early PleistoceneMiddle
Pleistocene lapse, another genus (Pampatherium) would have migrated
toward North America, originating the species Pampatherium mexicanum