Review of Colombian primates: ecology, natural history, distribution, conservation. Revision of book published in 2004.
Review of Colombian primates: ecology, natural history, distribution, conservation. Revision of book published in 2004.
This is the story of the revolutionary changes to South American mammals that occurred when it became possible for mammals from North America to pass to South America. This probably began as early as eight to ten million years ago when a... more
This is the story of the revolutionary changes to South American mammals that occurred when it became possible for mammals from North America to pass to South America. This probably began as early as eight to ten million years ago when a proboscid, camelid, tayassuid, and tapirid and procyonid arrived in South America. Later at about three million years ago, the invasion became a flood when (apparently) the terrestrial connection between the two continents became complete. Of course some South American fauna went north, as well, including a primate, terrestrial sloths and the glyptodonts and marsupials, but all but the marsupials became extinct after modest success. Other southern elements persist yet in Central America, including primates and caviomorph rodents.
Research Interests:
Research Interests:
Research Interests:
A bush dog(Speothos venaticus) pack in the eastern llanos of Colombia. TR Defler Journal of Mammalogy 67:22, 421-422, 1986. Though the range of the bush dog (Sperothos venaticus ) comprises most of the Neotropics, the ...
Research Interests:
This is a synopsis of what is known of South American mammals from the Mesozoic Era, which begins (according to present information) in the Early Jurassic around 183–174 Ma when a triconodont tooth was found in Patagonia. More spectacular... more
This is a synopsis of what is known of South American mammals from the Mesozoic Era, which begins (according to present information) in the Early Jurassic around 183–174 Ma when a triconodont tooth was found in Patagonia. More spectacular additions to the mammalian fauna are known for the Late Jurassic 168–161 million years ago, representing the most completely known biota from Middle to Late Jurassic for South America, comprising australosphenid mammals (relatives of the platypus) and the now extinct triconodont mammals. The Early Cretaceous became known for the increasing number of known fossils. This Cretaceous fauna was dominated in South America by dryolestid mammals, which were closely related to the modern placental mammals. During this latter part of the Mesozoic, a couple of spectacular fossils were found: Vincelestes neuquenianus and Cronopio dentiacutus, both of which are illustrated and discussed in this chapter. This ancient fauna survived the Chicxulub impact (the K/T transition) into the early part of the Paleogene but rather quickly replaced by a more modern fauna (the metatheres and primitive ungulates) that invaded from the north.
Research Interests:
From the time that the first xenarthrans appeared as early armadillos in the Early Paleocene Itaborai, the group diversified into strange and wonderful forms. Besides the Dasypodidae, a group called the Glyptodontidae arose and... more
From the time that the first xenarthrans appeared as early armadillos in the Early Paleocene Itaborai, the group diversified into strange and wonderful forms. Besides the Dasypodidae, a group called the Glyptodontidae arose and diversified; some were the size (and shape) of a Volkswagen bug and were harmless grazers. They were very common on the grassy savannas of South America. Also, the sloth lineage appeared with the last species reaching the greatest size of any southern mammal. Megatherium americanum became one of the largest mammals known in South America, equivalent in size to an elephant. Finally a short history of the little-known anteaters is presented. A discussion of the possible but unconfirmed origins of the xenarthra is suggested, and the group is presented as one of the most ancient lineages of modern mammals and native South Americans.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
This is a description of the well-known Colombian La Venta fauna. La Venta is the most detailed tropical faunal assemblage known for South America. Although it is located on the upper Magdalena River, at the time that it existed, it was... more
This is a description of the well-known Colombian La Venta fauna. La Venta is the most detailed tropical faunal assemblage known for South America. Although it is located on the upper Magdalena River, at the time that it existed, it was peripheral to the great Amazonian wetlands to the east: unlike today there was no Eastern Cordillera barrier. This fauna is represented by about 72 species of mammals from the richest deposits (the Monkey Beds) and is dated from about 11.8–13.5 million years ago (the Laventan SALMA), so it really represents a tropical community from a very narrow time window. The La Venta habitat was an open riparian-savanna with gallery forests, so mammals from several different habitats illustrate both forest and savanna mammals. Compared to previous chapters, this is a fairly modern fauna, yet no elements of the north are yet to be found, and the mix is rather different than that found in the high latitudes further south. It is notable that many species and genera of mammals from La Venta have also been found in tropical central Peru, suggesting that a band of similar habitat west of the Amazonian wetlands was continuous from northern Colombia to southern Peru at least during the Laventan SALMA.
Research Interests:
Research Interests:
Research Interests: Geography and Primatology
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
The hypothesis of Kinzey and Gentry [Primate Ecology: Problem Oriented Field Studies. New York, John Wiley & Sons, 1979] that Callicebus torquatus may be specialized for living in vegetation on white sand was evaluated by... more
The hypothesis of Kinzey and Gentry [Primate Ecology: Problem Oriented Field Studies. New York, John Wiley & Sons, 1979] that Callicebus torquatus may be specialized for living in vegetation on white sand was evaluated by reviewing all observations I made of this species, where the substrate had been noted, and including some collection sites of J. Hernández Camacho. There was no evidence for the white‐sand hypothesis. Instead, Callicebus torquatus was found to prefer upland and flooded forests that are tall and well stratified, and growing on many soil types, including white sand. © 1994 Wiley‐Liss, Inc.
Research Interests:
Research Interests: Zoology, Geography, Ecology, Medicine, Habitat, and 8 moreParapatry, National Park, Woodland, Sympatry, Mono, Gallery Forest, Nature Reserve, and Distributions
... A group of woolly monkeys (Lagothrix lagothricha), studied for 1,800 hr from June 1984 until September 1987 in the eastern Colombian Amazon, used ... Within the study area woolly monkeys occurred at a density of 5.5 individuals/km 2 .... more
... A group of woolly monkeys (Lagothrix lagothricha), studied for 1,800 hr from June 1984 until September 1987 in the eastern Colombian Amazon, used ... Within the study area woolly monkeys occurred at a density of 5.5 individuals/km 2 . The average day range was 2,880 m, and ...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Chapter1: Introduction -- Chapter2: Ancient mammals of Gondwanan South America -- Chapter3: Early Cenozoic mammals in South America -- Chapter4: Marsupials and other metatheres of South America -- Chapter5: The native ungulates of South... more
Chapter1: Introduction -- Chapter2: Ancient mammals of Gondwanan South America -- Chapter3: Early Cenozoic mammals in South America -- Chapter4: Marsupials and other metatheres of South America -- Chapter5: The native ungulates of South America -- Chapter6: The xenarthrans-armadillos, glyptodonts, anteaters, sloths -- Chapter7: The Caviomorphs – First South American Rodents -- Chapter8: The Platyrrhine Monkeys -- Chapter9: An Antarctic Eocene Mammalian Community -- Chapter10: La Venta: A Miocene Colombian Mammalian Community -- Chapter11: The Genesis of the Modern Amazon River Basin and its Role in Mammalian Evolution -- Chapter12: Mammalian Invasion of the Caribbean Islands -- Chapter13: The Great American Biotic Interchange -- Chapter14: Pleistocene Mammal Communities and their Extinction -- Chapter15: The Modern Mammals of South America.
Research Interests:
Research Interests:
This is a description of the South American fauna (and some that arrived from North America) that populated the Caribbean Islands and how this fauna might have arrived. Fossils tell us a story that recent extinctions of only the last few... more
This is a description of the South American fauna (and some that arrived from North America) that populated the Caribbean Islands and how this fauna might have arrived. Fossils tell us a story that recent extinctions of only the last few thousands of years probably were at least in part caused by the arrival of humans. Besides many species of ground sloths, there were at least five species of primates living on several Caribbean Islands, several of which lasted until the last few hundred years when they became extinct. All of these primates might have descended from one group of South American primates which arrived as far north as Cuba, although some hypothesize that there might have been various primate stocks that populated the islands. Although the sloths, primates, and caviomorphs suggest that the fauna entered from South America, intriguingly some mammalian groups from the continent are absent (e.g., carnivores, ungulates), making the theory of a land bridge difficult.
Research Interests:
The ancient, native ungulates were another fascinating group, which sadly has become totally extinct, but that we now understand were related to the northern Perissodactyla or odd-toed ungulates. These animals apparently evolved from... more
The ancient, native ungulates were another fascinating group, which sadly has become totally extinct, but that we now understand were related to the northern Perissodactyla or odd-toed ungulates. These animals apparently evolved from northern condylarths (primitive ungulates) that somehow made it to South America. Evolution produced five orders of quite bizarre ungulates, some more like rodents than like ungulates, but others, toward the end of the Neogene in the Pleistocene, had become large, rhinoceros-like Toxodon and camel-like Machrochenia. Although there is much to learn about the many species of South American meridiungulates (native ungulates), many forms are known. Some of the latest forms are known to have been hunted by Early humans, who finally arrived in South America.
Research Interests:
This is a description of the earliest (Paleocene-Eocene) mammalian assemblages known for the South American Cenozoic. These include complete discussions of the Tiupampan, Peligran, Itaboraian, and Riochican South American Mammal Ages... more
This is a description of the earliest (Paleocene-Eocene) mammalian assemblages known for the South American Cenozoic. These include complete discussions of the Tiupampan, Peligran, Itaboraian, and Riochican South American Mammal Ages (SALMAs). While the Tiupampan and Peligran SALMAs are the earliest assemblages and are placed in the Paleocene, recent dating places the Itaboraian and Riochican SALMAs in the Early Eocene. These assemblages contain the most ancient mammalian groups, the marsupials and native ungulates. These groups apparently arrived in South America from North America, perhaps in the latter part of the Cretaceous before the beginning of the Cenozoic. These faunas also contain other elements from North America and from the ancient Mesozoic mammalian fauna, which then become extinct in South America through competition with the more advanced northern groups. Several subgroups of marsupials and ungulates make their first appearance, as well as the first xenarthrans. A South American platypus demonstrates the ancient connection of South America to Australia, via Antarctica, and the early metatheres and ungulates exhibit clear connections to North America, though the exact date of their arrival and the route taken are not very clear. Nevertheless, the diversity of these mammals exhibited in the Tiupampan SALMA argues for an early arrival, perhaps even before the K/T boundary.
Research Interests:
Research Interests:
This chapter presents the partial evolutionary history known of the platyrrhine primates through their known fossils. New evidence for the earliest known primates comes to us from Peru, so that we now have tropical evidence of... more
This chapter presents the partial evolutionary history known of the platyrrhine primates through their known fossils. New evidence for the earliest known primates comes to us from Peru, so that we now have tropical evidence of Perupithecus and others, superseding the many higher-latitude primates known from the Southern Cone. The previous earliest known primates (Branisella, Szalatavus) are known also from a totally different habitat 20 million years later. These earliest fossils prove the important role of tropical forest in the evolution of South American primates. The newly discovered Eocene primates have similarities to early African fossils. In this chapter I describe how primates might have (and probably did) arrived in South America and just what the conditions would have had to be for the success of such a precarious voyage. New phylogenetic analyses point out the probable stem lines from the main crown primates that help clarify primate diversification in South America.
Research Interests:
Callicebus caquetensis es una especie de primate recientemente descrita Defler et al., 2010. Martin Moynihan (1976) en su libro New World Monkeys fue el primero en mencionar la existencia de esta nueva especie de Callicebus en el... more
Callicebus caquetensis es una especie de primate recientemente descrita Defler et al., 2010. Martin Moynihan (1976) en su libro New World Monkeys fue el primero en mencionar la existencia de esta nueva especie de Callicebus en el Departamento del Caqueta, Colombia, sin embargo, Hernadez-Camacho & Cooper (1976) y el reconocido mastozoologo Philip Hershkvitz en su revision de los Titis Neotropicales (1990) no incluyeron esta informacion. Van Roosmalen et al(2002) realiza una revision taxonomica de los Callicebus Neotropicales mencioando la informacion aportada por Moynihan. Defler (2003, 2004) hace alusion a las obsrevaciones de Moynihan y discute sobre la situacion de la seguridad que hacia dificil la busqueda de este primate en su localidad. La distribucion de la especie ha sido establecida a traves de entrevistas con la comunidad local y observaciones directas. Su habitat se encuentra en un avanzado estado de fragmentacion causado principalmente por la ganaderia extensiva. Hoy, 35 anos despues de las primeras observaciones, la especie se encuentra en peligro Critico de extincion. Se sugiere al gobierno nacional y del Caqueta que presten especial atencion a este primate endemico, estabilizando reservas en la zona. Se propone a la Universidad de la Amazonia como centro clave para la generacion de jovenes primatologos que desarrollen investigaciones orientadas al conocimiento basico y a la conservacion de Callicebus caquetensis. Esta es la probablemente la especie de primate mas amenazada de Colombia.
Research Interests:
This chapter discusses the origin of the Amazon basin and Andean uplift and their roles in mammalian evolution. Information is still sparse, due to taphonomic difficulties for fossil recovery and the widespread, deep covering of recent... more
This chapter discusses the origin of the Amazon basin and Andean uplift and their roles in mammalian evolution. Information is still sparse, due to taphonomic difficulties for fossil recovery and the widespread, deep covering of recent reworked sedimentary soils in a moist tropical, acid soil environment, but lately especially new finds of earliest rodent and primate fossils have added to our knowledge of how the tropical regions have played a large role in South American mammalian evolution, evidently through many different mechanisms. The process by which the great river was originally established is an important theme discussed as well as what the conditions must have been to allow invading mammals of open country and savannah from the north to arrive at the southernmost parts of the continent.
Research Interests:
Research Interests:
Colombia is one of the most biologically diverse countries in the world: although it takes up slightly less than one percent of the Earth's surface, it is home to approximately ten percent of the world's plants and animals,... more
Colombia is one of the most biologically diverse countries in the world: although it takes up slightly less than one percent of the Earth's surface, it is home to approximately ten percent of the world's plants and animals, including a diversity of primate species that is only superseded by Brazil and Peru in number. This vibrantly illustrated field guide is the result of field work conducted on Colombian primates both in and out of the country. The volume illustrates and describes twenty-eight primate species comprising forty-three taxa, of which fifteen taxa are only found in Colombia. The field guide also includes comprehensive chapters on primate classification, fossil history, and conservation, and each is augmented by numerous drawings, photographs, and maps. Primates of Colombia will be an invaluable resource for primatologists and naturalists alike.