Introduction: New World Primates

Abstract

With an evolutionary history dating back 30 million years, the Neotropical primates now present a remarkable radiation of monkeys, comprising some 200 extant taxa (c. 150 species), and ranging in size from the smallest anthropoid, the Pygmy marmoset Cebuella pygmaea at c. 100 g, to the muriquis (Brachyteles) and spider monkeys (Ateles) weighing more than 10 kg. They occur throughout the American tropics – the Mexican spider monkey Ateles geoffroyi just north of the Tropic of Cancer, and the Southern brown howler Alouatta guariba extends some distance south of the Tropic of Capricorn to (31°S), where the Atlantic forest gives way to the Pampas. There are three biogeographic communities for these primates, each having considerable endemism: (1) southern Mexico, Central America, and central and northern Colombia and Venezuela, with 45 taxa (spp and subspp); (2) the Amazon basin, including the Guianas and the eastern slopes of the Andes, with 135 taxa (spp and subspp); (3) the non-Amazonian tropical savannah (Cerrado), dry forests in north-east Brazil (Caatinga), southern Bolivia and Paraguay, the Chaco, and the lowland, montane, evergreen and semi-deciduous Atlantic forest in Brazil, Paraguay and Argentina, with 31 taxa (spp and subsp). Rosenberger (1992, 2011) neatly summarized the four principal adaptive zones of these primates using an ‘ecophylogenetic model’ of size, diet and locomotion. The first is occupied by the Callitrichidae (marmosets, Goeldi’s monkey Callimico goeldii, lion tamarins and tamarins); small (100–750 g) insectivore-frugivore-exudativores of the middle to lower canopy and understorey of the forest. They have specific adaptations for moving about on tree trunks, for vertical clinging and leaping (extreme in Pygmy marmosets and Goeldi’s monkey) and, in the