Meet “Ida”, the “missing link”

The discovery of one of the oldest and most complete fossil primates yet known was announced to much fanfare on Tuesday. Darwinius masillae, new genus, new species, is described in PLoS One, and has been nicknamed “Ida” by her describers.

In outward appearance, D. masillae is essentially lemurid, but lacks the derived characters of strepsirrhini such as the tooth-comb and toilet claw. The authors place the specimen in the adipoidea, and ally it with the haplorrhini, in which tarsiers, monkeys and apes are classified.

Although the authors have been quite explicit, saying they “do not interpret Darwinius as anthropoid”, this didn’t stop the press from immediately attaching the “missing link” label to the specimen, much to the chagrin of PZ Myers, John Wilkins and Chris Beard.

The concept of a “missing link” is irksome to many palaeonologists, who assert that it mischaracterises the relationships between extinct forms. However, two of Creationism’s favourite refrains are that the fossil record contains “too many gaps” and lacks “transitional forms”.

The first of these arguments is easily slapped down with the truism that every new fossil discovered creates two new gaps in the record.

The second is patent nonsense, since Archaeopteryx lithographica shares characters of birds and reptiles, Tiktaalik roseae shares fish and tetrapod characters, and Paleotherium, Ida’s contemporary, represents an early member of that most complete of lineages, the equids.

Ever since Darwin postulated a link between apes and humans (in The Descent of Man, not On the Origin of Species, as is popularly believed), people have demanded to see the evidence. One or two outstanding specimens such as Lucy and the Turkana Boy notwithstanding, the fossil record of primates has been comparatively sparse. So every new discovery is of crucial importance in greening the boughs of our family tree.

And now we have a spectacularly well-preserved fossil primate from an extremely early period in their history, one that has the potential to shed light on the ancestry of later groups, including the anthropoids.

So was it inevitable that the press should call her the missing link?

On this occasion they can be forgiven. Ida’s presentation to the world was accompanied by

Unfortunately the specimen may not live up to the hype. Laelaps is particularly critical of the authors for failing to “undertake a full, rigorous cladistic analysis to support their claims”.

Nevertheless, the specimen does perhaps deserve its own website, movie, and book deal, if not for its place in primate evolution, but for its spectacular preservation and the unusual circumstances of its discovery.

Ida was excavated from the Messel Pit in Germany, an oil shale deposit that has turned up numerous spectacular fossils, in 1983. It was immediately sold to a private collector who kept it from view for 24 years.

Rumours of its existence were occasionally heard in palaeontological circles, until Jørn Hurum was shown a photograph at a fossil fair in Frankfurt. The dealer indicated the collector was willing to sell the fossil for $1m. Knowing its importance, Hurum pleaded with the The University of Oslo Natural History Museum to acquire the specimen. Eventually they agreed to authorise the purchase, for a slightly lower fee, and Hurum bought it sight unseen.

It’s well worth watching the moment the Norwegians unwrapped their acquisition, which could so easily have ended in embarrassment and shame.

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