| Archicebus Temporal range: Early Eocene,
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|---|---|
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| Holotype | |
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Primates |
| Suborder: | Haplorhini |
| Infraorder: | Tarsiiformes |
| Family: | †Archicebidae Ni et al. 2013 |
| Genus: | †Archicebus Ni et al. 2013 |
| Species: | †A. achilles
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| Binomial name | |
| †Archicebus achilles Ni et al. 2013
| |
Archicebus is a genus of fossil primates that lived in the early Eocene forests (~55.8–54.8 million years ago) of what is now Jingzhou in the Hubei Province in central China, discovered in 2003.[1][2] The only known species, A. achilles, was a small primate, estimated to weigh about 20–30 grams (0.7–1.1 oz), and is the only known member of the family Archicebidae. When discovered, it was the oldest fossil haplorhine primate skeleton found,[3][4] appearing to be most closely related to tarsiers and the fossil omomyids, although A. achilles is suggested to have been diurnal, whereas tarsiers are nocturnal. Resembling tarsiers and simians (monkeys and apes), it was a haplorhine primate, and it also may have resembled the last common ancestor of all haplorhines as well as the last common ancestor of all primates.[5] Its discovery further supports the hypothesis that primates originated in Asia, not in Africa.[6]
YouTube Encyclopedic
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1/3Views:2 5202 988710
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NIU's Dan Gebo Discusses Oldest Known Primate Skeleton
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Reconstruction of racehorse Phar Lap's skeleton (time lapse)
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Sahelanthropus tchadensis - deform fossil to 3D reconstruction
Transcription
[NARRATOR] Dan Gebo doesn't monkey around when it comes to paleontology. In 2000 he and a team of researchers announced the discovery of forty-five million year old thumb-length fossils of what was, at the time, the smallest primates ever on Earth. Recently, Gebo and a team of paleontologists led by Xijun Ni of the Chinese Academy of Sciences in Beijing announced the discovery of primate fossils found in China dating back fifty-five million years, and although Archicebus (as they call it) can easily fit in the palm of your hand, there's nothing little about the discovery of the oldest and most complete primate skeleton ever found. [DR. DAN GEBO]The new discovery is coming from Central China and it is one of the oldest and most primitive of all the fossil primates, but probably the most interesting thing about it is it is an almost complete skeleton. It is the oldest primate skeleton bar none, so we have its tail, its legs, part of its back, pieces of its arm anatomy...we have teeth, we have parts of its head. It is fifty-five million years old, which is the beginning of the early Eocene Epoch, this is the very beginning of primate evolution. This skeleton is very small and can fit in the palm of your hand, but it's articulated, which means all the bones are attached to it. So you don't have to think about which bones go to what part of the body, we already know because they're actually in the right position. Once we found this fossil from China, which we named Archicebus, we started working with an NIU undergraduate artist who decided to come up with this image. You can see how small the primate is relative to the bumblebee and to the foliage. The first thing you might notice is it has fairly small eyes which means that it's diurnal, so this is an active primate in the daytime rather than a nocturnal, or nighttime, primate. The head is fairly small although the brain is a pretty good size relatively. It has a short nose, it has a long back with very long legs, and in particular you might notice how long the feet are. The feet are about, all the way from the heel here to about the way tips of the fingers or toes that go around the branch, it's about a third of the length of the entire leg so this thing has an incredibly long foot and has long legs to boot so it's a spectacular leaping primate, particularly for its size, it has a very long tail which we also find common to be among leaping primates and we decided to just kind of use a basic color pattern so we kind of went with the brown, a little reddish color background in terms of how it might look. This is a very unusual fossil, you find something like this maybe every fifty to one hundred years.
Etymology
Archicebus achilles was named for being the oldest-known primate skeleton (as of 2013[update]) and for its distinguishing calcaneus (heel bone).[5] The generic name, Archicebus, was constructed from arche (ἀρχή), the Ancient Greek word for "beginning", and cebus, the Latin version of the Ancient Greek kêbos (κῆβος), which refers to a long-tailed monkey. The species name, achilles, is a reference to Achilles, the Greek hero of the Trojan War from Greek mythology.[7]
Evolutionary history
Archicebus achilles exhibits similarities with simians with regard to the shape of its calcaneus and the proportions of its metatarsals, yet its skull, teeth, and appendicular skeleton resemble those of tarsiers. According to phylogenetic analysis, all of these traits taken together suggest it is the most basal member of the tarsiiform clade within the suborder Haplorhini. Considering its age, and since simians are a sister group to tarsiiforms, A. achilles may closely resemble the common ancestor of haplorhines and possibly the last common ancestor of all primates.[8]
| Phylogeny of primates[9] | ||||||||||||||||||
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| According to Ni et al. 2013, Archicebus is a basal member of the clade containing tarsiers, making it a close relative of monkeys and apes. |
Biogeography
The discovery of A. achilles adds further support to the hypothesis that primates originated in Asia, and not in Africa, with many simians (a group of them) migrating to the latter continent thereafter.[3]
Anatomy
A. achilles is estimated to have weighed 20 to 30 g (0.7 to 1.1 oz), making it comparable in size to today's smallest living primates, mouse lemurs.[9]
Range and ecology
A. achilles lived in the forests of the warm Eocene epoch, approximately 55.8 to 54.8 million years ago in a part of Asia near what now is Jingzhou, in the southern Hubei Province of China.[2][3][7]
Judging from its large canine teeth and sharp crests on its premolars, A. achilles was insectivorous. Unlike tarsiers, however, its smaller eyes suggest it was diurnal, a pattern previously suggested by other early haplorhines, such as Teilhardina asiatica. Its hind limbs suggest it did a lot of leaping; however, its hips, shoulders, and feet also suggest that it was not a vertical clinger and leaper such as tarsiers and galagos are, but likely moved through the trees in a more generalized quadrupedal fashion by grasping tree limbs from above.[8]
References
- ^ Ni et al. 2013, pp. 2 (sup).
- ^ a b Lei, Zhang; Fang, Qi (June 6, 2013). "I have scientists discovered the oldest fossil primate skeleton [Google translate]". Ifeng.com. Retrieved June 10, 2013.
- ^ a b c Wilford, J. N. (June 5, 2013). "Palm-size fossil resets primates' clock, scientists say". The New York Times. Retrieved June 5, 2013.
- ^ Jha, Alok (June 5, 2013). "Tiny, insect-eating animal becomes earliest known primate". The Guardian. Retrieved June 7, 2013.
- ^ a b Landau, Elizabeth (June 5, 2013). "Ancient primate could be a missing link". CNN. Retrieved June 7, 2013.
- ^ Wade, Lizzie (June 5, 2013). "Early Primate Weighed Less Than an Ounce". ScienceNow. Archived from the original on June 8, 2013. Retrieved June 7, 2013.
- ^ a b Ni et al. 2013, p. 60.
- ^ a b Ni et al. 2013, pp. 63–64.
- ^ a b Ni et al. 2013, p. 63.
Literature cited
- Ni, X.; Gebo, D. L.; Dagosto, M.; Meng, J.; Tafforeau, P.; Flynn, J. J.; Beard, K. C. (2013). "The oldest known primate skeleton and early haplorhine evolution". Nature. 498 (7452): 60–64. Bibcode:2013Natur.498...60N. doi:10.1038/nature12200. PMID 23739424. S2CID 4321956.
External links
- Primate skeleton could give clues about human origins (BBC News)
- Gron, Kurt J. (July 2008). "Primate Factsheets: Tarsier (Tarsius) Taxonomy, Morphology, & Ecology". National Primate Research Center, University of Wisconsin–Madison.
This page was last edited on 28 September 2023, at 02:28