Monday, May 25, 2009

Has The Missing Link Been Found?

The History Channel aired a program called, “The Link” on Monday, May 25, at 9 PM ET. The program chronicles the discovery of a fossil that experts say is over 47 million years old. The fossil is the skeleton of a primate that could be the long sought “missing link.”

The revelation of the landmark scientific fossilized remains of a primate is the most complete fossil primate ever found. It is of a young female specimen, known as “Ida,” is thought to revolutionize our understanding of human evolution. Twenty times older than most fossils that explain human evolution, “Ida” is a transitional species showing characteristics from the very primitive non-human evolutionary line but she is more related to the human evolutionary line. This places Ida at the very root of anthropoid evolution when primates were first developing the features that would eventually evolve into our own homo erectus.

Jørn Hurum from the Natural History Museum, University of Oslo, uncovered the primate through a chance encounter with a fossil dealer in Hamburg. Immediately recognizing its significance he procured it for his museum. Remarkably, it had been hidden from the world for 25 years in a private collection.

The fossil has been anallized and verified by the best in the science community. The primate lived in the early Middle Eocene during a critical period in evolutionary history when the extinction of the dinosaurs had occurred and mammals first began to thrive on the planet.

The Earth was beginning to take the shape as we would know it today. The Himalayas were forming, and early horses, bats, whales and many other fauna and flora started evolving. In the primate evolution, our own lineage, the anthropoids (monkeys, apes and humans), split from the branch leading to modern prosimians (lemurs, lorises and tarsiers).

It is the remarkable preservation of Ida's bones along with an imprint of her soft tissue and fur outline that makes this find so outstanding. The fossil even has evidence of her last meal. The wealth of information she provides will open a new chapter in the study of primate evolution.

Scientists have worked to identify the fossil and place it within the primate family tree. Ida was originally thought to be a primitive lemur, but comparative tests revealed her to have anthropoid features. This indicates that she is a transitional species between primitive primates and the human lineage. Two of the key anatomical features found in lemurs, a grooming claw on the foot and a fused row of teeth, a toothcomb, in the bottom jaw, are not present on the fossil. Instead she has a short face with forward-facing eyes, like ours, as opposed to the long face of a lemur, nails instead of claws, and teeth similar to those of monkeys.

The fossil's hands have five fingers and exhibit human-like opposable thumbs. These would have provided a "precision grip" which, for Ida, was useful for climbing and gathering fruit. In our case it enables important human functions such as making tools, and writing. Like us, Ida also had flexible arms and relatively short limbs.

Extensive X-rays, CT scanning and computer tomography have revealed Ida's age, sex and diet. Digital reconstructions of Ida's teeth reveal that she has unerupted molars in her jaw, indicating that she was about 9 months old, or the equivalent of a 6 years old human. The shape of Ida's teeth provides clues as to her diet; jagged molars would have allowed her to slice food, suggesting that she was a leaf and seed eater. This is confirmed by the remarkable preservation of her stomach content. Furthermore, the lack of a baculum (penis bone) means that the fossil was definitely female.
X-rays also reveal that her left wrist was healing from a bad fracture, which may have contributed to her death. The scientists believe she was overcome by carbon dioxide fumes whilst drinking from Messel Lake. Hampered by her broken wrist, she slipped into unconsciousness, was washed into the lake and sank to the bottom, where unique fossilisation conditions have preserved her for 47 million years.


  1. Great informative article regarding a subject I am very interested in. This information about Ida cmpletely passed below my horizon.
    The prosimians have always been fascinating to me and the very specialized isolated parts of the world that they now inhabit.
    This piece made me want to read more and learn about the discovery and knowlege gained from "Ida"
    Thank you sir!

  2. Hello Microdot,
    Thank you for the kind words. I will be following this topic as things develop more.