The spectacular Archaeopteryx fossil specimen at the Natural History Museum has been declared the official representative of the Archaeopteryx lithographica species, scientists report today.
Archaeopteryx lived 147 million years ago and had both bird and dinosaur features. Its discovery in Germany in 1861 provided the first evidence that birds evolved from dinosaurs.
Experts at the International Commission on Zoological Nomenclature (ICZN) ruled that the Museum specimen, which shows the almost complete skeleton of the magpie-sized creature with imprints of the wing and tail feathers, should be the type specimen, rather than a fossil of a imprint of a single feather that previously held the title.
Museum specimen showing the fossil tail of 147-million-year-old Archaeopteryx that shows the bird-like feather and dinosaur-like long bony tail.
A type specimen is the name given to a specimen that a scientist uses to provide the first description of a species. So, when they need to identify other similar animals, they can refer to the type specimen for comparison.
The ICZN provides the regulations for the naming of animal species worldwide, helping to ensure that names are universally used and remain stable. It also rules like a court in cases of dispute.
Dr Paul Barrett, fossil expert (palaeontologist) at the Natural History Museum comments on the decision. ‘We're delighted that the ICZN has decided that the Natural History Museum Archaeopteryx should be regarded as the primary reference specimen, or type specimen, of this iconic animal.
‘Researchers travel from all over the world to study our Archaeopteryx and it still occupies a central, crucial position in current controversies and debates over the relationships of early birds and other feathered dinosaurs.’
The ICZN decision took 5 years to make because there was controversy over whether it was justified to change the type specimen.
The change was strongly contested, both within the formal ICZN process and in informal discussion among taxonomists (scientists who describe, name and classify species).
The previous type specimen was a fossil of an imprint of a single feather uncovered from Solnhofen in Germany in 1861 and preserved on counterpart slabs of limestone. One half is looked after at the Humbolt Museum in Berlin, the other in Munich Museum, Germany. It was the specimen used in the first scientific description of Archaeopteryx, by German palaeontologist Hermann von Meyer, and so became the type specimen.
Painting of how Archaeopteryx may have looked 147 million years ago © John Sibbick / Natural History Museum
The Museum’s specimen was the first Archaeopteryx skeleton fossil uncovered, showing complete bones and feather impressions, and it came from the same limestone area close to Solnhofen, Germany. It was also scientifically described in 1861 by von Meyer.
However, it is now thought that the fossil feather may belong to another fossil bird species uncovered from the same area, and not to Archaeopteryx lithographica, and the ICZN agreed with this.
Dr Ellinor Michel, the Executive Secretary of the ICZN says, ‘Changing type specimens is not done lightly. What makes a specimen ideal can change with new methods and new philosophies of taxonomy. However, this case was seen as truly exceptional, as Archaeopteryx lithographica is our most iconic fossil bird’.
Barrett adds, ‘This decision clears up a long-standing anomaly as to how the species is defined, helping to facilitate future research on early birds. It also recognises the importance of the London specimen in shaping early debates on evolution and bird origins.’
Dr Angela Milner, Scientific Associate at the Natural History Museum, who has researched Archaeopteryx' brain structure and flying ability, says, 'The Natural History Museum's specimen was the most appropriate to become the type specimen since it was the first skeleton to be described.
'Scientists now have a large number of features of the skeleton, and the feather impressions in place on the wings and tail, as the primary reference for Archaeopteryx lithographica'.
One important role of natural history museums is to house and preserve type specimens. They represent some of the estimated 8.7 million species or organisms on Earth and naming them helps to make sense of such huge biodiversity.
The Natural History Museum has the largest collection of type specimens in the world with more than 850,000 type specimens.