Lemur's Little Finger Poses a Mystery

March 19, 2008
Lemur's Little Finger Poses a Mystery
The first handbones found of the ancient Hadropithecus lemur reveal a mystery arch by the little finger. Photo by Dr. Pierre Lemelin, University of Alberta

Analysis of the first hand bones belonging to an ancient lemur has revealed a mysterious joint structure that has scientists puzzled.

Pierre Lemelin, an assistant professor of anatomy at the University of Alberta in Edmonton, Canada, and a team of fellow American researchers have analyzed the first hand bones ever found of Hadropithecus stenognathus, a lemur that lived 2,000 years ago.

The bones were discovered in 2003 in a cave in southeastern Madagascar, an island nation off the coast of Africa in the Indian Ocean. Hadropithecus is related to the modern-day sifaka, a type of lemur with acrobatic leaping skills. A lemur is a monkey-like animal with a long tail and large eyes.

An examination of the five tiny hand bones by Lemelin and the rest of the research team revealed a never-before-seen hand joint configuration on the side of the little finger. The same joint configuration is straight in all other primates, including Archaeolemur, a close extinct relative of Hadropithecus.

“Our analysis showed a mosaic of lemurid-like, monkey-like and very unique morphological traits,” Lemelin said. “Because the joint was present on both hands, it’s likely not an anomaly, but because there are no other Hadropithecus hand bones for comparison, we don’t know for certain,” Lemelin said. “It is a mystery, and further investigation is needed to explain the difference in this species.”

Lemelin and his colleagues from George Washington University, the Medical College of Georgia, and the universities of Stony Brook and Massachusetts at Amherst, also discovered that, unlike its close living relatives, Hadropithecus lacked anatomical traits linked with wrist mobility and strong finger flexion that characterize primate species that climb or cling to trees.

The hand bones also showed that Hadropithecus had very short thumbs and was a quadrupedal species, walking on all fours, much like many primates, such as baboons, do today. The discovery underscores the amazing diversity of lemurs that existed more than 2,000 years ago, when lemurs of all types ranged from pocket-sized to the size of gorillas, Lemelin noted.

The findings were published this month in the Journal of Human Evolution.

Source: University of Alberta

Related Stories

Recommended for you

Who you gonna trust? How power affects our faith in others

October 6, 2015

One of the ongoing themes of the current presidential campaign is that Americans are becoming increasingly distrustful of those who walk the corridors of power – Exhibit A being the Republican presidential primary, in which ...

Ancient genome from Africa sequenced for the first time

October 8, 2015

The first ancient human genome from Africa to be sequenced has revealed that a wave of migration back into Africa from Western Eurasia around 3,000 years ago was up to twice as significant as previously thought, and affected ...

From a very old skeleton, new insights on ancient migrations

October 9, 2015

Three years ago, a group of researchers found a cave in Ethiopia with a secret: it held the 4,500-year-old remains of a man, with his head resting on a rock pillow, his hands folded under his face, and stone flake tools surrounding ...

Mexican site yields new details of sacrifice of Spaniards

October 9, 2015

It was one of the worst defeats in one of history's most dramatic conquests: Only a year after Hernan Cortes landed in Mexico, hundreds of people in a Spanish-led convey were captured, sacrificed and apparently eaten.


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.