Fossils: Shedding light on early primate evolution

The discovery of the oldest nearly complete skeleton of a primate, reported in this week’s Nature, provides insights into the earliest phases of primate evolution.

Artistic reconstruction of Archicebus achilles in its natural habitat of trees.

The creature is around 55 million years old and seems to be the earliest and most primitive known relative of the tarsiers. As tarsiers are related to anthropoids — the primates that include monkeys, apes and humans — the discovery shows that the lineage leading ultimately to humans was distinct at a very early date.

The primitive primate skeleton unearthed by Xijun Ni and colleagues is from the early Eocene (55.8–54.8 million years ago) of China. Analysis of the skeleton reveals a mixture of features — some that resemble anthropoids and some that resemble tarsiers. Its name, Archicebus achilles, roughly translates as ‘ancient monkey’ and also makes a cheeky reference to the animal’s anthropoid-like heel bone. These findings show that the age of the split between the Tarsiiformes and anthropoids, from which humans descend, is earlier than previously thought.

The tiny primate has a body that is around 71 mm long and its estimated weight is around 20–30 grams, as small as a modern pygmy mouse lemur. Certain features of the skeleton suggest that the creature was a frequent leaper, favouring four-limbed grasp-leaping as a mode of transport. Small pointy teeth indicate that it ate insects. Large eye sockets indicate that the creature had good vision for hunting, but evidence points towards a diurnal rather than nocturnal activity pattern.


Xijun Ni (Chinese Academy of Sciences, Beijing, China)
Tel: +86 10 8836 9270; E-mail: [email protected]


From North America and Canada
Neda Afsarmanesh, Nature New York
Tel: +1 212 726 9231; E-mail: [email protected]

From China
Lydia Chen, Nature Shanghai
Tel: +86 21 2422 5021; E-mail: [email protected]

From Japan, Korea, Singapore and Taiwan
Eiji Matsuda, Nature Tokyo
Tel: +81 3 3267 8751; E-mail: [email protected]

From the UK
Rebecca Walton, Nature London
Tel: +44 20 7843 4502; E-mail: [email protected]

About Nature Publishing Group (NPG):

Nature Publishing Group (NPG) is a publisher of high impact scientific and medical information in print and online. NPG publishes journals, online databases and services across the life, physical, chemical and applied sciences and clinical medicine.

Focusing on the needs of scientists, Nature (founded in 1869) is the leading weekly, international scientific journal. In addition, for this audience, NPG publishes a range of Nature research journals and Nature Reviews journals, plus a range of prestigious academic journals including society-owned publications. Online, provides over 5 million visitors per month with access to NPG publications and online databases and services, including Nature News and NatureJobs plus access to Nature Network and Nature Education’s

Scientific American is at the heart of NPG’s newly-formed consumer media division, meeting the needs of the general public. Founded in 1845, Scientific American is the oldest continuously published magazine in the US and the leading authoritative publication for science in the general media. Together with and 15 local language editions around the world it reaches over 3 million consumers and scientists. Other titles include Scientific American Mind and Spektrum der Wissenschaft in Germany.

Throughout all its businesses NPG is dedicated to serving the scientific and medical communities and the wider scientifically interested general public. Part of Macmillan Publishers Limited, NPG is a global company with principal offices in London, New York and Tokyo, and offices in cities worldwide including Boston, Buenos Aires, Delhi, Hong Kong, Madrid, Barcelona, Munich, Heidelberg, Basingstoke, Melbourne, Paris, San Francisco, Seoul and Washington DC. For more information, please go to


Caption: Illustration of an evolutionary tree, showing how Archicebus fits with respect to primate phylogeny.


Reconstruction of the fossil of Archicebus achilles, based on microtomography scanning.

Published: 05 Jun 2013

Contact details:

The Macmillan Building, 4 Crinan Street
N1 9XW
United Kingdom

+44 20 7833 4000
News topics: 
Content type: