Copright Natural History Museum
After five years of controversy, the fossil bird Archaeopteryx lithographica is to be officially represented by the spectacular specimen held by the Natural History Museum in London. This changes the primary reference, or type specimen, from an impression of a small fossil feather to the complete bones and feathers in a large limestone slab. The ruling is announced by theInternational Commission on Zoological Nomenclature (ICZN) in its latest publication, out today.
In 2006, a formal case was submitted to the ICZN requesting that the original type specimen for Archaeopteryx lithographica, the holotype, be replaced by a newly designated specimen, a complete specimen discovered later - a neotype. The change was strongly contested, both within the formal ICZN process and in informal discussion among taxonomists.
However, the ICZN agreed that the feather impression was not identiï¬able to a species and could belong to any taxon of fossil birds recognised from the same location. The best specimen for a neotype was declared to be the famous and very complete London Archaeopteryx.
âWeâre 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,â said Dr Paul Barrett, palaeontologist at the Natural History Museum.
He continued: âResearchers travel from all over the world to study our Archaeopteryx and it occupies a central, crucial position in current controversies and debates over the relationships of early birds and other feathered dinosaurs. 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.â
Archaeopteryx lithographica lived 147 million years ago in the Late Jurassic and was fossilised in the Solnhofen Limestone Formation in Germany. Archaeopteryx shows a critical shift in evolution. Its mix of dinosaur and bird characteristics shows that modern birds descended from small meat-eating dinosaurs. It had wings and feathers very like those of modern birds and a long bony feathered tail and was about the same size as a magpie. But Archaeopteryxâs skeleton also has features in common with small meat-eating dinosaurs such as teeth with serrated edges and interdental plates, and three fingers ending in claws.
A type specimen is how scientists tie a name to a standard example of a species so that it is indisputable what the name refers to. It is generally considered best that type specimens stay constant, even if they are not ideal specimens. In exceptional circumstances researchers can apply to the ICZN to override the rules and change type specimens, the equivalent of taking an issue to court. Cases of this sort go through a process similar to a legal trial, with a formal presentation of the case, a period of public input similar to open testimony, and judgment by the ICZN.
âChanging type specimens is not done lightly. What makes a specimen ideal can change with new methods or alternative philosophies of taxonomy. However, this case was seen as truly exceptional, as Archaeopteryx lithographica is our most iconic fossil bird,â said Dr Ellinor Michel, the Executive Secretary of the ICZN.
Ensuring that species names mean what people think they mean is critical for reliable science, and normally the first example of a species that is described is the type specimen. A core role of natural history museums is to house and preserve type specimens, anchoring our information on biodiversity. The Natural History Museum in London has the largest collection of type specimens in the world.
Notes to editors
Abstract of the Case and Comments: http://iczn.org/category/volumeissue/bulletin-zoological-nomenclature/volume-68-2011
The official Opinion (for editors only, not yet on public release): http://bit.ly/oRuz2P
For a copy of the Case, images or interviews, please contact
Dr Ellinor Michel, Executive Secretary, ICZN
Tel: +44-207-942-5653 or mobile +44-750-607-1547
Chloe Kembery, Head of Media Relations, Natural History Museum
Tel: +44-207-942-5654 or mobile +44-779-969-0151
- The International Commission on Zoological Nomenclature is an international body of experts on scientific nomenclature who act as the arbiter on scientific names of animals. The Commissionâs job is to ensure names of animals are stable and universal by applying the rules of the International Code of Zoological Nomenclature, or occasionally by overriding the rules of the Code to better serve stability. www.iczn.org
- The Natural History Museum is a world-leading science research centre and also winner of Visit Londonâs 2010 Evening Standardâs Peoples Choice Best London for Free Experience Award and Best Family Fun Award. Through its collections and scientific expertise the Museum is helping to conserve the extraordinary richness and diversity of the natural world with groundbreaking projects in more than 70 countries.