MACNBR   00242
MUSEO ARGENTINO DE CIENCIAS NATURALES "BERNARDINO RIVADAVIA"
Unidad Ejecutora - UE
artículos
Título:
New mammals from the Allen Formation, Late Cretaceous, Argentina
Autor/es:
ROUGIER, G.W.; CHORNOGUBSKY, L.; CASADÍO, S.; PÁEZ ARANGO, N.; GIALLOMBARDO, A.
Revista:
CRETACEOUS RESEARCH (PRINT)
Editorial:
Elsevier
Referencias:
Año: 2009 vol. 2009 p. 223 - 238
ISSN:
0195-6671
Resumen:
A mammalian fauna from the Late Cretaceous locality of Cerro Tortuga, Allen Formation, Rý´o Negro
Province, Argentina, is described here based on a sample, represented by 7 isolated teeth which shows
similarities with those reported from the Late Cretaceous Los Alamitos Formation. These two mammalian
faunas largely agree on their overall composition at the supraspecific level but new species are recognized
for some of the specimens described. Small-sized dryolestoids, mesungulatids and ferugliotheriids
are present in Cerro Tortuga. A new species of Mesungulatum, [Bonaparte, J.F., Soria, M.F., 1985. Nota sobre
el primer mamý´fero del Creta´ cico Argentino, Campaniano-Maastrichtiano, (Condylarthra). Ameghiniana
21, 177183] leads to a reassessment of mesungulatid diversity in the Late Cretaceous South American
mammalian faunas and some provisional considerations on the relative age of the mammal-bearing
units. The South American Late Cretaceous radiation of dryolestoids has its origins in the early Late
Cretaceous, at the latest, and extends into the Paleocene when their last remnants are obliterated
possibly in relation to the incoming Laurasian tribosphenic mammals. The Late Cretaceous nontribosphenic
mammals have no clear link with the Jurassic and Early Cretaceous South American
mammals, emphasizing the distinctiveness and episodic nature of the Mesozoic South American
mammalian assemblages. The scant number of fossils and geochronologically discontinuous record may
artificially accentuate the distinctiveness of the as yet poorly known pre-Late Cretaceous South American
mammals, in particular if an epiric sea separated South Amerca into northen and southern realms.Mesungulatum, [Bonaparte, J.F., Soria, M.F., 1985. Nota sobre
el primer mamý´fero del Creta´ cico Argentino, Campaniano-Maastrichtiano, (Condylarthra). Ameghiniana
21, 177183] leads to a reassessment of mesungulatid diversity in the Late Cretaceous South American
mammalian faunas and some provisional considerations on the relative age of the mammal-bearing
units. The South American Late Cretaceous radiation of dryolestoids has its origins in the early Late
Cretaceous, at the latest, and extends into the Paleocene when their last remnants are obliterated
possibly in relation to the incoming Laurasian tribosphenic mammals. The Late Cretaceous nontribosphenic
mammals have no clear link with the Jurassic and Early Cretaceous South American
mammals, emphasizing the distinctiveness and episodic nature of the Mesozoic South American
mammalian assemblages. The scant number of fossils and geochronologically discontinuous record may
artificially accentuate the distinctiveness of the as yet poorly known pre-Late Cretaceous South American
mammals, in particular if an epiric sea separated South Amerca into northen and southern realms.