Fossil that contains seeds of knowledge
THE ancestor to modernday sparrows and finches flew around Earth 52million years ago, a new study found.
The fossilised seed-eating bird with a finch-like beak is one of the earliest examples of a perching bird ever found.
Most of the birds we now see – such as sparrows, finches, robins, crows – have one crucial thing in common, they are all perching birds, or ‘passerines’.
These type of birds make up about 6,500 of the 10,000 bird species alive today and are everywhere.
But once they were extremely rare, and how these perching birds evolved and when has been shrouded in mystery.
Now scientists at Chicago’s Field Museum of Natural History have found the earliest known passerine bird in a rich seam of fossil deposits known as Fossil Lake in Wyoming.
It dates from the Early Eocene which was distinctly warmer than today and linked to an explosion in the diversity of life. Neguanee Distinguished Service Curator Dr Lance Grande said: ‘This is one of the earliest known perching birds. It’s fascinating because passerines today make up most of all bird species, but they were extremely rare back then. This particular piece is just exquisite. It is a complete skeleton with the feathers still attached, which is extremely rare.’
The paper published in the journal Current Biology describes two new fossil bird species. One was from Germany that lived 47million years ago while the other lived in Wyoming 52million years ago. The Wyoming bird, Eofringillirostrum boudreauxi, is the earliest example of a bird with a beak that’s similar to today’s sparrows and finches.
This legacy is reflected in its name: Eofringilllirostrum means ‘dawn finch beak’. The fossil birds’ finchlike, thick beaks hint at their diet.
Lead author Dr Daniel Ksepka, curator at the Bruce Museum in Connecticut said: ‘These bills are particularly well-suited for consuming small, hard seeds. Anyone with a birdfeeder knows that lots of birds are nuts for seeds, but seed-eating is a fairly recent biological phenomenon. The great distance between the two fossil sites implies that these birds were widespread during the Eocene, while the scarcity of known fossils suggests a rather low number of individuals.’
Evolutionary biologist Dr Grande added: ‘The earliest birds probably ate insects and fish. Until now, we did not know much about the ecology of early passerines.’
Co-author Dr Gerald Mayr of the Senckenberg Research Institute in Frankfurt said: ‘Knowing what happened in the past gives us a better understanding of the present and may help us figure out where we are going for the future.’
Clues to evolution of perching birds