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| Reconstruction of M. pentelicus from Shuitangba. Image credit: Mauricio Antón |
A combined team of American and Chinese palaeontologists have examines fossils found in a lignite mine in south-eastern Yunan Province, China, and concluded that they are the oldest fossils of monkeys yet found outside Africa. At about 6.4 million years old, they coexisted temporally and geographically with early apes.
The significance of these fossils, appart from being some thousand times older than Creationists believe the Universe to be, is explained by A'ndrea Elyse Messer in a Penn State University news release:
"This is significant because they are some of the very oldest fossils of monkeys outside of Africa," said Nina G. Jablonski, Evan Pugh University Professor of Anthropology, Penn State. "It is close to or actually the ancestor of many of the living monkeys of East Asia. One of the interesting things from the perspective of paleontology is that this monkey occurs at the same place and same time as ancient apes in Asia."
The researchers, who included Jablonski and long-time collaborator Xueping Ji, department of paleoanthropology, Yunnan Institute of Cultural Relics and Archaeology, Kunming, China, studied the fossils unearthed from the Shuitangba lignite mine that has yielded many fossils. They report that "The mandible and proximal femur were found in close proximity and are probably of the same individual," in a recent issue of the Journal of Human Evolution. Also uncovered slightly lower was a left calcaneus — heel bone — reported by Dionisios Youlatos, Aristotle University of Thessaloniki, Greece, in another paper online in the journal, that belongs to the same species of monkey, Mesopithecus pentelicus.
"The significance of the calcaneus is that it reveals the monkey was well adapted for moving nimbly and powerfully both on the ground and in the trees," said Jablonski. "This locomotor versatility no doubt contributed to the success of the species in dispersing across woodland corridors from Europe to Asia."
Fossilized heel bone of M. pentelicus.
Image: Xueping Ji,
Yunan Institute of Cultural Relics and Archaeology
Photograph of the fossilized jawbone of a Miocene monkey, M. pentelicus.
Image: Xueping Ji,
Yunan Institute of Cultural Relics and Archaeology
The lower jawbone and upper portion of the leg bone indicate that the individual was female, according to the researchers. They suggest that these monkeys were probably "jacks of all trades" able to navigate in the trees and on land. The teeth indicate they could eat a wide variety of plants, fruits and flowers, while apes eat mostly fruit.
"The thing that is fascinating about this monkey, that we know from molecular anthropology, is that, like other colobines (Old World monkeys), it had the ability to ferment cellulose," said Jablonski. "It had a gut similar to that of a cow."
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"These monkeys are the same as those found in Greece during the same time period," said Jablonski. "Suggesting they spread out from a center somewhere in central Europe and they did it fairly quickly. That is impressive when you think of how long it takes for an animal to disperse tens of thousands of kilometers through forest and woodlands."
While there is evidence that the species began in Eastern Europe and moved out from there, the researchers say the exact patterns are unknown, but they do know the dispersal was rapid, in evolutionary terms. During the end of the Miocene when these monkeys were moving out of Eastern Europe, apes were becoming extinct or nearly so, everywhere except in Africa and parts of Southeast Asia.
"The late Miocene was a period of dramatic environmental change," said Jablonski. "What we have at this site is a fascinating snapshot of the end of the Miocene — complete with one of the last apes and one of the new order of monkeys. This is an interesting case in primate evolution because it testifies to the value of versatility and adaptability in diverse and changing environments. It shows that once a highly adaptable form sets out, it is successful and can become the ancestral stock of many other species."
As mentioned above, the team published their findings, open access, in the Journal of Human Evolution:
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| Photo of the section at Shuitangba, which produced the Mesopithecus fossils. The mandible, femur, and calcaneus were recovered from positions at the tips of the arrows. |
Abstract
A dentate mandible and proximal femur of Mesopithecus pentelicus Wagner, 1839 are described from the Shuitangba lignite mine in Zhaotong Prefecture, northeastern Yunnan Province, China. The remains were retrieved from sediments just below those that yielded a juvenile Lufengpithecus cranium and are dated at about ∼6.4 Ma. The mandible and proximal femur were found in close proximity and are probably of the same individual. The lower teeth are metrically and morphologically closely comparable with those of confirmed M. pentelicus from Europe, and on this basis, the specimen is assigned to this species. The anatomy of the proximal femur indicates that the Shuitangba Mesopithecus was a semiterrestrial quadruped that engaged in a range of mostly arboreal activities, including walking, climbing, and occasional leaping, with an abducted hip joint. The Shuitangba Mesopithecus is dentally typical for the genus but may have been more arboreal than previously described for M. pentelicus. M. pentelicus is well known from late Miocene (MN 11–12) sites in Europe and southwest Asia. Its estimated average rate of dispersal eastward was relatively slow, although it could have been episodically more rapid. The presence of a colobine, only slightly lower in the same section at Shuitangba that produced Lufengpithecus, is one of the only two well-documented instances of the near or actual co-occurrence of a monkey and ape in the Miocene of Eurasia. At Shuitangba, M. pentelicus occupied a freshwater-margin habitat with beavers, giant otters, swamp rabbits, and many aquatic birds. The presence of M. pentelicus in southwest China near the end of the Miocene further attests to the ecological versatility of a species long recognized as widespread and adaptable. The modern colobines of Asia, some or all of which are probable descendants of Mesopithecus, have gone on to inhabit some of the most highly seasonal and extreme habitats occupied by nonhuman primates.
Jablonski, Nina G.; Ji, Xueping; Kelley, Jay; Flynn, Lawrence J.; Deng, Chenglong; Su, Denise F.
Mesopithecus pentelicus from Zhaotong, China, the easternmost representative of a widespread Miocene cercopithecoid species
Journal of Human Evolution 2020; 146; p 102851. DOI: 10.1016/j.jhevol.2020.102851
Copyright: © 2020 The Authors. Published by ScienceDirect (Elsevir)
Open access
Reprinted under a Creative Commons Attribution 4.0 International License (CC BY 4.0)
This is a good example of how, when the conditions are favourable, a species can radiate very quickly to fill suitable niches. In this case, a species which probably originaed in what is now Eastern Europe spread quickly across Eurasia and also probably down into Africa. Once the climate changed and the forest corridor across central Asia disappeared, so did the monkeys, leaving South and East Asia and Africa as the main centres of Monkey populations.
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