A fossil owl monkey from La Venta, Colombia

Abstract

Knowledge of the evolutionary history of living New World anthropoids is limited by a relatively poor fossil record. The discovery in 1986 of a new fossil monkey from the middle Miocene deposits of La Venta, Colombia, 12-15 million years ago (Myr BP), is the first example of a living New World monkey genus appearing in Tertiary rocks. Including anatomical evidence of the dentition and facial skull, it provides an unambiguous link between a Neogene fossil and the owl monkey, Aotus, the only modern crepuscular-nocturnal anthropoid primate. This new form brings to three the number of La Venta fossil monkeys which preserve excellent dentitions sharing extensive similarities with modern genera. All of these species are potentially ancestral to their extant relatives. The La Ventan Aotus is additional support for the idea that the modern platyrrhine radiation includes long-lived genera or generic lineages, some of which may be traceable to the early Miocene, 20 Myr BP.

Olfactory fossa of Tremacebus harringtoni (platyrrhini, early Miocene, Sacanana, Argentina): Implications for activity pattern

“…The next oldest possible sister taxon to Aotus is Aotus dindensis ϭ Mohanamico hershkovitzi (middle Miocene, Colombia). This species probably had enlarged orbits (Setoguchi and Rosenberger, 1987). On the other hand, if Mohanamico hershkovitzi (Luchterhand et al, 1986) and "Aotus dindensis" are conspecific and related to pitheciines as argued by Kay (1990), then possibly nocturnality arose independently twice in platyrrhine evolution: once in the Mohanamico hershkovitzi lineage and a second time independently in the Aotus lineage.…”

“…The only possible, if implausible, alternative interpretation is that Tremacebus was nocturnal and evolved a tapetum. Mohanamico hershkovitzi (Aotus dindensis) (Luchterhand et al, 1986) from 12.8-Myr-old levels in Colombia probably had large orbits also and therefore could have been nocturnal, although only a small part of the orbit is preserved (Setoguchi and Rosenberger, 1987).…”

A New Platyrrhine from the Middle Miocene of La Venta, Colombia, and the Phyletic Position of Callicebinae.

“…In the La Venta fauna a fossil owl monkey, Aotus dindensis, was discovered in the lowest part of the Villavieja Formation in the 1980s (locality number, 9-86A; see Figs. l and 3; Setoguchi and Rosenberger, 1987;Kay, 1990;Rosenberger et al, 1990). The type specimen of this species consists of a left mandibular corpus preserving I1-M3 and a right maxillary fragment preserving a fragment of M3, so it is impossible to make a direct comparison between Miocallicebus and A. dindensis.…”

“…, Stirton, 1951;Rosenberger et al, 1991;Takai, 1994; Naka tsukasaet al, 1997); Cebupithecia sarmientoi (Stirton, 1951;Meldrum and Kay, 1997); Micodon kiotensis (Setoguchi and Rosenberger, 1985); Mohanamico hershkovitzi (Luchterhand et al, 1986); Aotus dindensis (Setoguchi and Rosenberger, 1987); Lagonimico conclutatus (Kay, 1994), Patasola magdalenae (Kay and Meldrum, 1997); and Nuciruptor rubicae (Meldrum and .…”

“…Fleagle, 1999): Stirtonia and Neosaimiri are regarded as the ancestral taxa of living howler monkeys (Alouatta) and squirrel monkeys (Saimiri), respectively (e.g. Stirton, 1951;Hershkovitz, 1970;Rosenberger, 1979); Cebupithecia and Nuciruptor are thought to be ancestral sakis (pitheciines) (Stirton, 1951;Meldrum and Kay, 1997); Aotus dindensis is considered as the middle Miocene species of Aotus (and/or Mohanamico, see Luchterhand et al, 1986;Setoguchi and Rosenberger, 1987;Kay, 1990;Rosen bergeret al, 1990); Micodon, Lagonimico and Patasola are included in the Calli trichinae (Setoguchi and Rosenberger, 1985;Kay, 1990;Kay and Meldrum, 1997).…”