Researchers at Bournemouth University have resolved a 150-year-old mystery regarding an extinct giant crane that inhabited Europe over 20,000 years ago. A new ancient DNA study reveals the fossil bones actually belong to larger versions of today’s common European crane rather than a separate extinct species.
Bournemouth University and Centre for Palaeogenetics Solve Fossil Identity
Scientists at Bournemouth University in the UK, working in partnership with the Centre for Palaeogenetics in Stockholm, Sweden, turned to genetic testing to settle a century-and-a-half-old debate. In the 19th century, French biologist Alphonse Milne-Edwards named the primeval giant bird Grus primigenia
after examining bone fragments discovered in caves located in the south of France. Those remains were dated to the end of the last ice age.
For generations, the scientific consensus held that these bones belonged to an entirely distinct species of giant crane. However, a research team led by Dr John Stewart, Professor of Evolutionary Palaeoecology at Bournemouth University, found through ancient DNA analysis that the prehistoric specimens are actually larger versions of the living common crane seen across Europe today.
We suspected that these large cranes were not extinct and instead represented larger, modern European common cranes. We believe that the reason for the mistaken identity was that cranes have large males and smaller females and we think this contributed to previous speculation that there were two different species – the living, common crane we see today and the extinct, larger species.
Dr John Stewart, Professor of Evolutionary Palaeoecology at Bournemouth University
DNA Analysis Replaces 19th-Century Morphological Methods
To uncover the truth behind the skeletal remains, the international team extracted genetic material from 18 crane bones found across England, Wales, France, Germany, and the Balearic Islands. Dr Stewart pointed out that earlier research relied exclusively on measuring the size and shape of skeletal fragments.
According to the research team, utilizing DNA analysis provided a much clearer picture of what the bones actually represent. This methodological shift suggests that other prehistoric bird species currently classified solely by physical size differences may require similar genetic scrutiny to confirm their identities.
While it is true that many species of birds are vulnerable to human actions today, it may be that we have overestimated the number of extinctions in the past. Some of these may instead represent size changes to living species.
Dr John Stewart, Professor of Evolutionary Palaeoecology at Bournemouth University
Investigating Why European Cranes Shrank Over Time
With the identity of the bones established, Dr Stewart and his colleagues are turning their attention to understanding why these ancient birds decreased in physical size between the end of the last ice age and the modern era.
Researchers suspect that shifts in human land use and wetland drainage drove the shrinking trend, though further investigations are required to definitively answer the question.
The challenge going forwards is to investigate the reason for the cranes decrease in size. Wetland drainage and human land use changes are what we suspect, but more work is needed to resolve that.
Dr John Stewart, Professor of Evolutionary Palaeoecology at Bournemouth University
