INVESTIGADORES
FERNICOLA Juan Carlos
congresos y reuniones científicas
Título:
Evaluating habitats and feeding habits through ecomorphological features in glyptodonts (Mammalia, Xenarthra)
Autor/es:
VIZCAÍNO, S. F.; CASSINI, G. H.; FERNICOLA, J. C.; BARGO, M. S.
Lugar:
San Juan
Reunión:
Congreso; IV Congreso Latinoamericano de Paleontología de Vertebrados; 2011
Resumen:
Glyptodonts are very peculiar extinct mammals of the
New World that vanished as part of the great end-Pleistocene extinction of
continental mammals. The goal of this study is to evaluate ecomorphological
variables in glyptodonts from different ages (Miocene to Pleistocene), clades,
and sizes, with the purpose of inferring their habitats and feeding habits. The
analyses include estimation of body masses and three variables: dental occlusal
surface area (OSA), relative muzzle width (RMW) and hypsodonty index (HI). The
major deviations from the correlation between OSA and body mass are recorded in
two of three taxa larger than 1000 kg: Panochthus Burmeister, 1866 and Doedicurus
Burmeister, 1874. The first lies markedly above the regression line and the
latter well below, suggesting that these two forms resulted from divergent
evolutionary pathways. RMW allows the distinction of two main groups: the
small-sized Early Miocene propalaehoplophorids were selective feeders, while
the larger post-Miocene forms were more bulk feeders. The Pleistocene Glyptodon
Owen, 1839 appears as an exception, implying a reversion to a selective
feeding behavior. The relation between RMW and HI allows discriminating feeding
niche partitioning in glyptodonts. Among the early Miocene
propalaehoplophorids, Eucinepeltus Ameghino, 1891 would have been a
highly selective feeder in relatively closed environments, Propalaehoplophorus
Ameghino, 1887 a highly selective feeder in moderately open habitats, and Cochlops
Ameghino, 1889 a less selective feeder in moderately open habitats. Among
the large Pliocene and Pleistocene taxa, Neuryurus Ameghino, 1889 and Neosclerocalyptus
Paula Couto, 1957 were probably bulk feeders in relatively open environments,
while Panochthus and Doedicurus were bulk feeders in open
environments. Alternative interpretations can be assessed for Glyptodon:
it was a more selective feeder in closer habitats, or had a different feeding
behavior, browsing on specific plants at higher levels from the ground, and/or
a specialized physiology. The late Miocene and Pliocene forms (Hoplophractus
Cabrera, 1939, Eosclerocalyptus Ameghino, 1919, and Urotherium Castellanos,
1926) were probably intermediate between the Miocene and the Pleistocene ones.