Featured Research

from universities, journals, and other organizations

Fossil primate shakes up history of tooth-combed primates

Date:
December 11, 2013
Source:
CNRS
Summary:
Fossils discovered in Tunisia challenge several hypotheses concerning the origin of tooth-combed primates (Malagasy lemurs, Afro-Asian lorises and African galagos). The fossils are of a small primate called Djebelemur, which lived around 50 million years ago.

Djebelemur martinezi. Artist's reconstructions based on life-history traits inferred from the study of new fossil remains.
Credit: © Laurence MESLIN / CNRS, Institut des Sciences de l’Evolution de Montpellier (ISE-M).

Fossils discovered in Tunisia challenge several hypotheses concerning the origin of tooth-combed primates (Malagasy lemurs, Afro-Asian lorises and African galagos). The fossils are of a small primate called Djebelemur, which lived around 50 million years ago. They were discovered by a French-Tunisian team from the Institut des Sciences de l'Evolution in Montpellier (CNRS/Université Montpellier 2/IRD) and the Office National des Mines (ONM) in Tunis.

According to the paleontologists, Djebelemur was probably a transitional form leading to the appearance of tooth-combed primates. However, according to genetic data, these primates appeared at least 15 million years earlier. Djebelemur therefore challenges the hypotheses put forward by molecular biology. The work, which has just been published in PLoS One, makes it possible to reconstruct a chapter in the evolutionary history of this lineage. In addition, it may help to refine genetic models.

Tooth-combed primates, also called strepsirrhines, comprise lemurs and lorisiforms (small primates which include lorises and galagos). In these primates, the anterior teeth of the lower jaw take the form of a comb. This is mainly used for grooming, but also, in some species, for procuring the natural gums that make up part of their diet.

A key question debated by primatologists concerns the time when strepsirrhine primates first appeared. Recent genetic data dates the origin of lemurs and lorises to the onset of the Tertiary period, just after the disappearance of the dinosaurs (approximately 65 million years ago). Some molecular biologists even believe that divergence of the two groups occurred 80 million years ago. However, paleontological data does not corroborate these hypotheses: the oldest known lorisiform fossil dates from a mere 37 million years ago. Could this simply be due to a gap in the fossil record? The fossils discovered by the Institut des Sciences de l'Evolution in Montpellier (CNRS/Université Montpellier 2/IRD) and the ONM in Tunis suggest otherwise: it is the genetic models that may need to be revised.

Discovered in the sediments of a former lake in Djebel Chambi National Park, Tunisia, the approximately 50 million-year-old fossils belong to a small primate called Djebelemur (lemur of the Djebel). This was a tiny animal weighing scarcely 70 g. It was most certainly nocturnal, a predator of insects and a tree-dweller. Some of its morphological characteristics suggest that it was a distant relative of lemurs, galagos and lorises. However, although it did not yet have such a specialized toothcomb, it exhibited a tooth structure that had already been transformed, an early stage of the anterior dentition of today's strepsirrhines.

Djebelemur thus appears to be a transitional form, pre-dating the lorisiform-lemuriform divergence. Therefore, tooth-combed primates probably did not originate as early as molecular biologists have claimed. This is likely to have occurred less than 50 million years ago, the age of the Djebelemur fossil.

This is not the first time that genetic data disagrees with paleontological data. For many groups of mammals, geneticists tend to put forward earlier dates of origin than those provided by direct observation of the fossil record. Molecular biology increasingly seeks to refine its models by constraining them with fossil data. In the case of the origin of tooth-combed primates, Djebelemur could prove to be a significant milestone making it possible to reset the molecular clock and improve estimates of divergence dates derived from molecular phylogenies.


Story Source:

The above story is based on materials provided by CNRS. Note: Materials may be edited for content and length.


Journal Reference:

  1. Laurent Marivaux, Anusha Ramdarshan, El Mabrouk Essid, Wissem Marzougui, Hayet Khayati Ammar, Renaud Lebrun, Bernard Marandat, Gilles Merzeraud, Rodolphe Tabuce, Monique Vianey-Liaud. Djebelemur, a Tiny Pre-Tooth-Combed Primate from the Eocene of Tunisia: A Glimpse into the Origin of Crown Strepsirhines. PLoS ONE, 2013; 8 (12): e80778 DOI: 10.1371/journal.pone.0080778

Cite This Page:

CNRS. "Fossil primate shakes up history of tooth-combed primates." ScienceDaily. ScienceDaily, 11 December 2013. <www.sciencedaily.com/releases/2013/12/131211070215.htm>.
CNRS. (2013, December 11). Fossil primate shakes up history of tooth-combed primates. ScienceDaily. Retrieved July 26, 2014 from www.sciencedaily.com/releases/2013/12/131211070215.htm
CNRS. "Fossil primate shakes up history of tooth-combed primates." ScienceDaily. www.sciencedaily.com/releases/2013/12/131211070215.htm (accessed July 26, 2014).

Share This




More Fossils & Ruins News

Saturday, July 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Did ISIS Destroy Jonah's Tomb?

Did ISIS Destroy Jonah's Tomb?

Newsy (July 25, 2014) — Unverified footage posted to YouTube purportedly shows ISIS militants destroying a shrine widely believed to be the tomb of the prophet Jonah. Video provided by Newsy
Powered by NewsLook.com
Richard III's Car Park Burial Site Opens to Public

Richard III's Car Park Burial Site Opens to Public

AFP (July 25, 2014) — Visitors will be able to look down from a glass walkway on the grave of King Richard III when a new centre opens in the English cathedral city of Leicester, where the infamous hunchback was found under a car park in 2012. Duration: 00:35 Video provided by AFP
Powered by NewsLook.com
Mobile App Gives Tour of Battle of Atlanta Sites

Mobile App Gives Tour of Battle of Atlanta Sites

AP (July 25, 2014) — Emory University's Center for Digital Scholarship has launched a self-guided mobile tour app to coincide with the 150th anniversary of the Civil War's Battle of Atlanta. (July 25) Video provided by AP
Powered by NewsLook.com
Tyrannosaur Pack-Hunting Theory Aided By New Footprints

Tyrannosaur Pack-Hunting Theory Aided By New Footprints

Newsy (July 24, 2014) — A new study claims a set of prehistoric T-Rex footprints supports the theory that the giant predators hunted in packs instead of alone. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins