LibriumArcana.Games

Giant prehistoric geese the size of small plane

By Richard Alleyne
Last Updated: 7:01pm BST 26/09/2008

Giant prehistoric geese the size of small aircraft once flew over Britain, scientists have discovered.

Dasornis, which had a 16 ft wingspan and sharp teeth, lived 50 million years ago and was related to present-day ducks and geese.

Dasornis are related to modern day ducks and geese - Giant prehistoric geese the size of small aircraft

Once it skimmed the waters which covered what is now London, Essex and Kent, snapping up fish and squid with its bony-toothed beak.

Scientists announced the discovery of one of the best preserved Dasornis fossil skulls buried in clay on the Isle of Sheppey.

Dasornis was in many ways similar to the modern albatross, which has the largest wingspan of any living bird, but research has shown that its closest cousins are ducks and geese.

Dr Gerald Mayr, from the Senckenberg Research Institute in Frankfurt, Germany, who described the find today in the journal Palaeontology, said: "Imagine a bird like an ocean-going goose, almost the size of a small plane.

"By today's standards these were pretty bizarre animals, but perhaps the strangest thing about them is that they had sharp, tooth-like projections along the cutting edges of the beak.

"No living birds have true teeth - which are made of enamel and dentine - because their distant ancestors did away with them more than 100 million years ago, probably to save weight and make flying easier.

"But the bony-toothed birds, like Dasornis, are unique among birds in that they reinvented tooth-like structures by evolving these bony spikes.

"These birds probably skimmed across the surface of the sea, snapping up fish and squid on the wing.

"With only an ordinary beak these would have been difficult to keep hold of, and the pseudo-teeth evolved to prevent meals slipping away."

The fossil is in a collection at the Karlsruhe Natural History Museum, Germany.

Plumage breakthrough for dinosaurs

By Roger Highfield, Science Editor
Last Updated: 1:01am BST 09/07/2008

The ability to reconstruct the colour of fossil feathers that adorned the first birds and their ancestors, the dinosaurs, has come from a discovery reported today.

Traces of organic material have been found in fossil feathers that are remnants of the pigments that once gave birds their hue, according to Yale University scientists who believe that fossilized fur should be able to yield its colour too.

Study of a number of fossilized bird feathers by student Jakob Vinther revealed that organic imprints in the fossils - previously thought to be carbon traces from bacteria - are fossilised melanosomes, the structures in cells that contain a pigment called melanin.

However, the team has not yet exploited the discovery to reconstruct ancient plumage.

"Birds frequently have spectacularly coloured plumage which are often used in camouflage and courtship display," said Vinther.

"Feather melanin is responsible for rusty-red to jet-black colours and a regular ordering of melanin even produces glossy iridescence. Understanding these organic remains in fossil feathers also demonstrates that melanin can resist decay for millions of years."

Working with palaeontologist Prof Derek Briggs and ornithologist Prof Richard Prum, Vinther analysed a striped feather found in 100 million-year-old rocks from the Lower Cretaceous Period in Brazil. The team reports in the journal Biology Letters that it used a scanning electron microscope to show that dark bands of the feather preserved the arrangement of the pigment-bearing structures as a carbon residue - organized much as the structures are in a modern feather. The light bands showed only rock surface.

In another fossil of a bird from the Eocene Epoch - 55 million years ago - in Denmark there were similar traces in the feathers surrounding the skull. That fossil also preserved an organic imprint of the eye and showed structures similar to the melanosomes found in eyes of modern birds.

"Many other organic remains will presumably prove to be composed of melanin," said Vinther.

He expects that fur of ancient mammals and skin from dinosaurs preserved as organic imprints will likely be the remains of the melanin.

"The discovery has, we believe, great potential but we haven’t yet had an opportunity to apply it to many specimens," added Prof Briggs.

"It just goes to show that the fossil record is still full of surprises. Now that we have demonstrated that melanin can be preserved in fossils, scientists have a way to reliably predict, for example, the original colours of feathered dinosaurs," said Prof Prum.