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19 The Fossil Vertebrate Record of Venezuela of the Last 65 Million Years Marcelo R. Sánchez-Villagra, Orangel A. Aguilera, Rodolfo Sánchez, and Alfredo A. Carlini In his 1940 “Review of the mammal-bearing Tertiary of South America,” G. G. Simpson summarized the scanty record of Venezuela (703–704): “Few as discoveries are, they are important because they show unquestionable affinities with fossil mammals of Argentina and none with those of North America. In view of the fact that no South American mammals had reached North America in the Miocene or earliest Pliocene, even this small budget of evidence is enough to prove that South America was then a unified continent with its northern and southern parts united by land and that the northern part, as well as the southern, was then separated from North America by a marine barrier.” What little was known about northern neotropical vertebrate paleontology in 1940 was already important in addressing some large issues about biogeography and the past history of the American continent. Vertebrate paleontology in Venezuela is still in a descriptive phase, but the number of discoveries has increased exponentially in the last few years, and contributions in this volume exemplify how some of them are being used to address fundamental issues about evolution in the tropics and major events in vertebrate evolution, such as the Great American Biotic Interchange in both terrestrial and marine habitats. Here we present a chronological review of Venezuelan formations and sites with reported fossil vertebrates. Many of the sites and their fossils are also discussed specifically in different chapters of this book. Paleogene vertebrates from Venezuela are almost unknown. Several aspects on paleoenvironments and palynology of the Paleocene and Eocene of Venezuela were discussed by Rull (2000). There are several Neogene fossil sites, but most are poorly known localities with only one or a few taxa or remains reported. By far the most important section with vertebrates in the Cenozoic of Venezuela is that of the Urumaco sequence , the geology of which is treated in a separate chapter (Quiroz and Jaramillo this volume). Most vertebrate faunas from the Neogene show very low diversity, with the sole exception of the Urumaco sequence and the Cerro La Cruz site. Faunas with vertebrates are found in the Guárico sub-basin, Barinas basin, and Falcón basin. Pleistocene and Holocene deposits are becoming better known, and as discussed below the recently 3 Sánchez-Villagra, Aguilera, Sánchez, and Carlini 20 discovered tar pits in Zulia state and the archeological sites in Falcón state are the most significant sites. Many of the fossils mentioned below are in collections in Europe and the USA. In Venezuela, vertebrate fossils are reposited principally in the following institutions: Collección Urumaco Rodolfo Sánchez Alcald ía, Estado Falcón (AMU-CURS); Centro de Historia de la Ciudad de Trujillo, Colección de Geología y Paleontología (CH-V); Centro de Investigaciones Antropológicas, Arqueológicas, y Paleontológicas, Coro (CIAAP); Museo de Biología de la Universidad del Zulia, Paleontología (MBLUZ-P); Museo de Ciencias Naturales de Caracas (MCNC); Universidad Nacional Experimental Francisco de Miranda, Coro (UNEFM); Universidad Nacional Experimental Francisco de Miranda, Coro / Centro de Investigaciones Antropológicas, Arqueológicas y Paleontológicas, Coro (UNEFM-CIAAP); Universidad Simón Bolívar, Laboratorio de Paleobiología (USB-PB). The sedimentary basins of Venezuela (fig. 3.1) contain large volumes of oil, and this has led to long-standing great interest in the Venezuelan geology (Tankard, Suárez, and Welsink 1995). In northern Venezuela, uplift events range in time from the latest Eocene through the present, producing sediments that were arranged in molasse cycles (Macsotay et al. 1995). From west to east, orogenic phases produced the Mérida Andes, Coastal Range (“Caribbean Mountains”), Eastern Interior, Araya-Paria, and Northern and Central Ranges of Trinidad. The molasse cycles attained several kilometers’ thickness of sediments, many of which contain fossil vertebrates. Of particular interest is the Falcón basin, one of the major sedimentary regions in the Cenozoic of Venezuela (fig. 3.1). Several formations in this basin are rich in fossil vertebrates. Recognizing these formations is sometimes a nomenclatural issue, although the geology of the region is well mapped. Approximately 40% of the formation names used by Liddle (1946) for Venezuela in the classic work The Geology of Venezuela and Trinidad are no longer in use. The “Léxico Estratigr áfico de Venezuela” (Ministerio de Energía y Minas 1997) has...

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