Fossil Ida: The Missing Link?

By Cleveland Glass

Ida is a , recently discovered, 47 million year old primate fossil, who was originally thought to be a Lemur-like creature, but upon closer examination was found to have features that are strikingly similar to our own. She is, therefore, believed to be a transitional species between Prosimians (Lemurs and their kin) and Simians ( Monkey, Apes, and Human Beings).

Ida has been proclaimed as our evolutionary link to the rest of the animal kingdom. Sir David Attenborough said, “This little creature is going to show us our connection with the rest of the mammals.”…”The link they would have said up to now is missing – well it’s no longer missing.”

Fossil Ida was discovered by an amateur fossil hunter, in the summer of 1983, at Messel pit, near Frankfurt, Germany, where she had been preserved in the oil shale. Interestingly, being unaware of the fossils significance, the original owner kept it a secret for 20 years.

At the time Ida lived, 47 million years ago, Messel pit was a volcanic lake surrounded by sub-tropical forest. Because of its unique environment, Messel has yielded a good variety of artifacts, including fossils of insects, bats, crocodiles and pygmy horses.

Messel Pit may have looked like this during the Eocene period (47 million years ago).

Dr Jørn Hurum, Vertebrate Palaeontologist, was the first to recognize the significance of the fossil. In 2006, Hurum was approached by a private dealer, Thomas Perner, who offered him the fossil for $1 million at an annual Fossil and Mineral Fair in Germany. Hurum then sought to find a natural history museum able to pay for the specimen. Eventually, Hurum convinced the Natural History Museum of Oslo to secure it.

The specimen was named after Dr Hurum’s daughter, Ida (Pronounced “ee-dah”).

Dr Jørn Hurum

Following its acquisition, Dr Hurum put together a Dream Team of Internationally renowned scientists that studied Ida for for a period of two years to determine its significance.

The team included Professor Philip Gingerich  and Dr Holly Smith of the University of Michigan, along with Dr. Jens Franzen and Dr. Jörg Habersetzer of the Senckenberg Research Institute.

Dr Jens Franzen

Professor Philip Gingerich

The team chose to publish their finding in PLoS ONE, the open access journal of the Public Library of Science, rather than in the most prestigious scientific journals. Dr Hurum explained that he wanted to make the information available to as many people as possible, without having to charge them.

X-rays performed on fossil Ida reveal that she had a fractured left wrist, which may have contributed to her death. “Scientists speculate she was overcome by carbon dioxide fumes while drinking from the Messel lake. Hampered by her broken wrist, she slipped into unconsciousness, was washed into the lake and sank to the bottom, where unique fossilization conditions preserved her for 47 million years.” (Wikipedia)

Because of her extraordinary preservation, Ida is the most complete fossil primate ever discovered, being 95% complete, with only its left rear leg missing. Prior to Ida’s discovery, Lucy was the most famous primate in the world, and she was only 40% complete.

Based on radiometric dating of Messel’s volcanic rock, scientists have determined that Ida lived 47 million years ago during the Eocene period. “During that period, the first whales, horses, bats and monkeys emerged, and the early primates branched into two groups”.. Alex Watts, Sky News Online.

The scientific name for Ida’s species is Darwinius Masillae. The genus Darwinius was named in celebration of Charles Darwin on his bicentenary. The species was named masillae in commemoration of Messel, the place where the specimen was found.

Ida was a small Lemur-like monkey, about 3ft long, from head to tail. The lack of a bacculum (penis bone) indicates that she was a female. Scientists believe that she was only 9 months old when she died (Equivalent to a 6 year old child).

Ida had jagged molars that allowed her to slice food and an analysis of her gut contents showed that her last meal consisted leaves and seeds.

Ida is missing two key anatomical features that are found in Lemurs:

1) Grooming Claw on the foot.

2) Toothcomb in the lower row of teeth. (Used for grooming fur)

1) A short face rather than the long face that is typical among Lemurs.

2) Forward focusing eyes which probably gave her 3-D, binocular vision.

3) Human-like nails rather than claws.

4) Five fingers with human-like opposable thumbs. This gave her precision grip for climbing and gathering fruit.

5) Flexible arms and short limbs.

6) A distinctive ankle “talus” bone. (Which humans still have)

So what are Ida’s human-like features that have convinced scientists that she is a transitional species?

1) There is no evidence to suggest that Ida’s species is a direct ancestor of humans.

2) She is only one of many links in the long chain of Human Evolution.

However,“Ida is a remarkably complete specimen that promises to teach us a great deal about the biology of some of the earliest and least human-like of all known primates, the Eocene adapiforms. For this, we can all celebrate her discovery as a real advance for science. “ Chris Beard (New Science Magazine)

So, Is Ida (Darwinius masillae ) the so called “Missing Link” in Human Evolution?

Scientists say NO – for the following reasons: