Search results
Results from the WOW.Com Content Network
Other similar basal primates were widespread in Eurasia and Africa during the tropical conditions of the Paleocene and Eocene. Purgatorius is the genus of the four extinct species believed to be the earliest example of a primate or a proto-primate, a primatomorph precursor to the Plesiadapiformes, dating to as old as 66 million years ago.
Primates range in size from the 30-gram (1 oz) pygmy mouse lemur to the 200-kilogram (440 lb) mountain gorilla. According to fossil evidence, the primitive ancestors of primates may have existed in the late Cretaceous period around 65 mya (million years ago), and the oldest known primate is the Late Paleocene Plesiadapis , c. 55–58 mya.
Plesiadapis is one of the oldest known primate-like mammal genera which existed about 58–55 million years ago in North America and Europe. [ 2 ] [ 3 ] Plesiadapis means "near-Adapis", which is a reference to the adapiform primate of the Eocene period , Adapis .
Sir Wilfrid Le Gros Clark was one of the primatologists who developed the idea of trends in primate evolution and the methodology of arranging the living members of an order into an "ascending series" leading to humans. [7] Commonly used names for groups of primates such as prosimians, monkeys, lesser apes, and great apes reflect this methodology.
A 2014 whole-genome molecular dating analysis indicated that the gibbon lineage diverged from that of great apes (Hominidae) around 17 million years ago (16.8 ± 0.9 Mya), based on certain assumptions about the generation time and mutation rate.
The encephalization quotient of some cetaceans is therefore higher than that of most primates, including the nearest relatives of humans, such as Australopithecus. [8] This list follows partly from Walter Carl Hartwig's 2002 book The Fossil Primate Record [9] and John G. Fleagle's 2013 book Primate Adaptation and Evolution (3rd edition). [10]
Primatomorpha is a subdivision of Euarchonta including primates and their ancestral stem-primates Plesiadapiformes. An early stem-primate, Plesiadapis, still had claws and eyes on the side of the head, making it faster on the ground than in the trees, but it began to spend long times on lower branches, feeding on fruits and leaves.
One study based on DNA analysis suggests that Scandentia and Primates are sister clades, but does not discuss the position of Dermoptera. [9] Although it is known that Scandentia is one of the most basal Euarchontoglires clades, the exact phylogenetic position is not yet considered resolved, and it may be a sister of Glires, Primatomorpha or Dermoptera or to all other Euarchontoglires.