Print ISSN: 0031-0247
Online ISSN: 2274-0333
Hypoplasia: CT-scan or naked eye?
Eocene otoliths (Clinchfield Formation), Georgia
New elephant cranium from early Pliocene Ileret, Kenya
Early adaptive radiation of Theridomorpha
Evolution et extinction des reptiles marins au Mésozoïque
Les vertébrés fossiles de Colombie et les problèmes posés par l'isolement du Continent sud-Américain.Columbia; Cretaceous; Fauna; Quaternary; South America
A general view is given of the vertebrate faunas, Cretaceous to Quaternary of age, found in Columbia and of their principal characteristics. This view leads to the discussion of the isolation of the South American continent and of the role played by the Bolivar syncline with respect to North American immigrants during the Oligocene. The absence of marine deposits of Oligocene age in the north and northwest of Columbia suggests the possibility of a communication with Central America. This communication would have permitted the passage of hystricomorph rodents, of platyrrhine monkeys, and of colubrids. The non-occupation, until then, of the ecologie niches of these groups would have favored their installation beside the indigenous fauna. In this hypothesis it would no longer be necessary to admit that these vertebrates arrived as «island hoppers ››. The eco-biologic conditions would explain the absence of large-sized forms of North American origin.
Published in Vol. 02, Fasc. 2 (1969)