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	Ida lived in the early ] during a period in evolutionary history after the extinction of the dinosaurs, when mammals first began to thrive on the planet. In primate evolution, the ]s – monkeys, apes, and humans – split from the branch leading to modern ] – lemurs, lorises, and tarsiers.		Ida lived in the early ] during a period in evolutionary history after the extinction of the dinosaurs, when mammals first began to thrive on the planet. In primate evolution, the ]s – monkeys, apes, and humans – split from the branch leading to modern ] – lemurs, lorises, and tarsiers.

	Scientists have worked to identify the fossil and place it within the ] family tree along with other ]. Ida was originally thought to be a primitive ], but comparative tests revealed her to have anthropoid features. This indicates that she is a ] between primitive primates and the human lineage.{{fact}} Two of the key anatomical features found in lemurs, a ] on the foot and a fused row of teeth, a ], in the bottom jaw, are not present on the fossil. Instead, she has a short face with forward facing eyes like humans as opposed to the long face of a lemur, nails instead of claws, and teeth similar to those of monkeys.		Scientists have worked to identify the fossil and place it within the ] family tree along with other ]. Ida was originally thought to be a primitive ], but comparative tests revealed her to have anthropoid features. This indicates that she may be, what ] call, a ] between primitive primates and the human lineage.{{fact}} Two of the key anatomical features found in lemurs, a ] on the foot and a fused row of teeth, a ], in the bottom jaw, are not present on the fossil. Instead, she has a short face with forward facing eyes like humans as opposed to the long face of a lemur, nails instead of claws, and teeth similar to those of monkeys.
	]s of the ''Darwinius'' holotype fossil]]		]s of the ''Darwinius'' holotype fossil]]
	The fossil's hands have five fingers and exhibit human-like ].<ref> , a May 19, 2009 article from ]</ref> These would have provided a "precision grip" which, for Ida, was useful for climbing and gathering fruit. Ida also had flexible arms and relatively short limbs.		The fossil's hands have five fingers and exhibit human-like ].<ref> , a May 19, 2009 article from ]</ref> These would have provided a "precision grip" which, for Ida, was useful for climbing and gathering fruit. Ida also had flexible arms and relatively short limbs.

Revision as of 12:38, 20 May 2009

Darwinius Temporal range: Mid Eocene
File:Darwinius masillae.jpg
Left and right (reversed) side of the Darwinius masillae holotype fossil
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Primates
Infraorder:	Adapiformes
Family:	Notharctidae
Genus:	Darwinius
Species:	D. masillae
Binomial name
*Darwinius masillae* Franzen et al., 2009

Darwinius masillae ("Darwin's creature from the Messel pit," named to celebrate Charles Darwin's bicentenary) is a basal or stem group primate from the Eocene. The only known fossil, dubbed Ida, was recovered in 1983 from the Messel pit, a disused shale quarry near the village of Messel, about 35 kilometres (22 mi) southeast of Frankfurt am Main. The fossil, divided in two sections after the amateur excavation and sold separately, was not reassembled until 2007.

Ida is a specimen of an extinct primate species that lived 47 million years ago. It is said to be significant as a transitional form (a so-called "missing link") between early primitive primates and the later prosimian and simian lineages. The creature appeared superficially similar to a modern lemur, but had opposable thumbs. The fossil is classified to lie near the separation of two major primate clades, one leading to the prosimians, the other to the anthropoid monkeys and, eventually, to the great apes including Homo sapiens. The animal, which is related to other dry nosed Haplorrhini primates, lived during the Lutetian stage of the Eocene Epoch. Concerns have been raised about the claims made in publicising the fossil before adequate information was available for scrutiny.

Type specimen

The type specimen, a 95%-complete fossil, has been named "Ida" after the daughter of Jørn Hurum, the Norwegian paleontologist who secured one section of the fossil from an anonymous owner, and led the research.

In addition to the bones, an imprint of Ida's soft tissue and fur outline is present, along with remnants of her last meal of fruit and leaves. At the time its discovery was announced, in the scientific and the popular press, the fossil was characterized as the "most complete fossil primate ever discovered"; it is missing only its left rear leg. Sir David Attenborough has described it as "an extraordinary fossil."

Ida lived in the early Middle Eocene during a period in evolutionary history after the extinction of the dinosaurs, when mammals first began to thrive on the planet. In primate evolution, the anthropoids – monkeys, apes, and humans – split from the branch leading to modern prosimians – lemurs, lorises, and tarsiers.

Scientists have worked to identify the fossil and place it within the primate family tree along with other fossil primates. Ida was originally thought to be a primitive lemur, but comparative tests revealed her to have anthropoid features. This indicates that she may be, what evolutionists call, a transitional fossil 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 humans 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. Ida also had flexible arms and relatively short limbs.

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 year 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 gut content. Furthermore the lack of a baculum (penis bone) means that the fossil was definitely female.

X-rays reveal that her left wrist was healing from a bad fracture, which may have contributed to her death. The scientists speculate she was overcome by carbon dioxide fumes whilst 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 fossilisation conditions preserved her for 47 million years.

Discovery

The significance of the fossil was first recognised by vertebrate palaeontologist Dr. Jørn Hurum from the Natural History Museum, University of Oslo, who uncovered the specimen through a chance encounter at the Hamburg Fossil and Mineral Fair, Germany in 2006 where a dealer offered the fossil for $1 million. It had been discovered 23 years earlier by an amateur fossil hunter, but remained hidden from the world in a private collection. Hurum acquired the specimen for his museum based on photographs alone, allowing it to be seen and scientifically studied for the first time.

Since its rediscovery it has been studied in secret for two years by a team of scientists; Hurum was joined by primate evolution expert Professor Philip Gingerich of the University of Michigan, and palaeontologists Dr. Jens Franzen and Dr. Jörg Habersetzer of the Senckenberg Museum's Research Institute. They revealed their findings to the world in a paper published on 19 May 2009 in PLoS ONE, the open access journal of the Public Library of Science.

Publicity

The paper on the fossil was accompanied by a documentary (Uncovering Our Earliest Ancestor: The Link), made by Atlantic Productions in the UK, to be screened on the History Channel (US) and BBC One (UK) - directed by Tim Walker and produced by Lucie Ridout. A book The Link: Uncovering Our Earliest Ancestors by Colin Tudge and a website, were also launched to explain the significance of the fossil to a broader audience. The New York Daily News noted that "The unveiling of the fossil came as part of a carefully-orchestrated publicity campaign unusual for scientific discoveries."

Independent experts have raised concern about publicity exaggerating the importance of the find before information was available for scrutiny. Jørn Hurum during a ceremony at the American Museum of Natural History said that "This specimen is like finding the Lost Ark for archeologists" and "It is the scientific equivalent of the Holy Grail. This fossil will probably be the one that will be pictured in all textbooks for the next 100 years.". News coverage has described the discovery as "the missing link in human evolution" and the "eighth wonder of the world" which "finally confirms Charles Darwin's theory of evolution." Science historian John Wilkins has commented that there is no missing link, which is an outdated concept dating back to the great chain of being; instead, there are an infinite number of missing branches in Darwin's metaphor of the tree of life. Brian Switek, while describing the fossil as spectacularly complete and "the first time a fossil primate has been found exhibiting such extraordinary preservation," deplores the sensationalist coverage and a lack of adequate research in the published paper to back claims that it is an ancestor of the earliest anthropoids.

Notes

^ Christine McGourty (19 May 2009). "Science & Environment; Scientists hail stunning fossil". BBC News. Retrieved 2009-05-20.
Wilford, John Noble (May 16, 2009). "Analysis Shows German Fossil to Be Early Primate". New York Times. {{cite news}}: Cite has empty unknown parameter: |coauthors= (help)
^ Franzen, Jens L. (2009). "Complete Primate Skeleton from the Middle Eocene of Messel in Germany: Morphology and Paleobiology". PLoS ONE. 4 (5): e5723. doi:10.1371/journal.pone.0005723. {{cite journal}}: Cite has empty unknown parameter: |month= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)CS1 maint: unflagged free DOI (link)
^ Brian Switek (May 19, 2009). "Poor, poor Ida, Or: "Overselling an Adapid" : Laelaps". Retrieved 2009-05-20.
"Norske forskere: – Har funnet «the missing link»". Retrieved 2009-05-20. {{cite web}}: Cite has empty unknown parameter: |coauthors= (help)
A History Channel documentary, The Link, devoted to the discovery is slated to air 25 May 2009.
The Implications from revealingthelink.com, the website for the documentary about the type specimen
Early Primate Provides Evolution Clues, a May 19, 2009 article from ABC News
Fossil Ida: extraordinary find is 'missing link' in human evolution, a 19 May 2009 article from The Guardian
Little Brown, 2009
Hurum, Jørn (2009). "The Link". Retrieved 2009-05-20.
^ Samantha Strong and Rich Schapiro (May 19, 2009). "Missing link found? Scientists unveil fossil of 47 million-year-old primate, Darwinius masillae". Retrieved 2009-05-20.
Scientists Unveil Missing Link In Evolution, sky.com, May 19, 2009
John Wilkins (May 11, 2009). "There is no missing link : Evolving Thoughts". Retrieved 2009-05-20.