Zoologists have unearthed fossils of the world's oldest known hummingbirds in Germany. The nectar feeders are now extinct in the Old World.

The pair of 30-million-year-old skeletons are less than five centimetres long and resemble modern hummingbirds, according to a study in Friday's issue of the journal Science.

"It is the first definite record of a modern-type hummingbird found in the Old World," said Gerald Mayr, a zoologist from Forschungsinstitut Senckenberg, a natural history museum in Frankfurt.

The fossilized remains of an Eurotrochilus inexpectatus (AP PHOTO)

The fossils were found in a clay deposit near the village of Frauenweiler in southern Germany. Until the German find, hummingbird fossils from Central America, dated to about one million years ago, were thought to be the oldest.

Mayr called the new species Eurotrochilus inexpectatus or "unexpected European version of Trochilus." Modern hummingbirds are in the genus Trochilus.

The fossils are similar to modern hummingbirds in size, bone structure and beak length. Their beaks were twice as long as their skulls and their wings were designed to hover.

The extinct hummingbirds may have helped determine the shape of some Asian and African flowers through "coevolution," Mayr said.

Although scientists don't know why hummingbirds went extinct in the Old World, they've speculated climate change, or competition with other birds or insects may be behind the loss.