MACNBR   00242
MUSEO ARGENTINO DE CIENCIAS NATURALES "BERNARDINO RIVADAVIA"
Unidad Ejecutora - UE
capítulos de libros
Título:
The evolution of armored xenarthrans and a phylogeny of glyptodonts
Autor/es:
FERNICOLA, J. C.; VIZCAÍNO, S. F.; FARIÑA, R. A.
Libro:
Biology of the Xenarthra
Editorial:
University of Florida Press (EEUU)
Referencias:
Año: 2008; p. 79 - 85
Resumen:
Armored xenarthrans (Cingulata) have been divided in two groups, informally denominated armadillos and glyptodonts. No doubt, glyptodonts represent one of the most bizarre groups of mammals ever to have evolved. Their most remarkable anatomical features are the presence of an immobile dorsal carapace, trilobate teeth, elephantine hind-limbs and a masticatory apparatus telescoped. The first mention of a South American armored xenarthran was carried out by Thomas Falkner in 1774, who commented to have discovered a great carapace comparable to that of the armadillos. It was Dámaso Antonio Larrañaga who, although indirectly, gave the first scientific news with regard to a great armored extinct animal. This fossil material was assigned to “Dasypus (Megatherium Cuv.)” by Larrañaga, and as such included by Cuvier in his Recherches sur les ossements fossiles. The fact that his opinion was published in Cuvier’s work caused that several incomplete fossil materials described later on were recognized in a same way. In 1839, Richard Owen revised all the references of armored megatheres and established that the big armored animals belong to the group of the glyptodonts, related with the armadillos, and that the megatheres did not present carapace. Traditionally, the classification and phylogeny of the glyptodonts were based on the study of the external surface of the bony scutes and the caudal tube. This fact contrasts with the usual phylogenetic studies of the remaining mammals, in which skull features play a central role. In agreement with these phylogenetic analyses, it was studied the craniodental morphology of 12 genera of glyptodonts to work out its phylogeny using cladistic methodology. This first phylogenetic study questioned all the previously proposed clusters, based on the morphology of scutes and caudal tube. Indeed, Fernicola found monophyletic groups previously considered paraphyletic (e.g. Propalaehoplophorinae), while others, formerly considered monophyletic, were solved otherwise (e.g. Sclerocalyptini, Plohophorini)