close
This ad will auto close in 10 seconds


Colours of dinos

Last Updated: Thursday, January 28, 2010 - 09:06

Paris: Scientists on Wednesday said they had identified true colours of a dinosaur for the first time, a feat that also explained what role feathers played in the evolution of birds.

Using electron microscopes, they identified minute, pigment-carrying cell structures in the fossilised bristles of a small dino that lived in the Early Cretaceous era, some 125 million years ago.

From this, they deduct that the mohawk-quiffed carnivore was probably russet in colour and boasted a stripey orange-and-white tail.

The breakthrough scanning technique may not be able to reveal the tint of other dinosaur species that had reptilian scales, say the British and Chinese team.

But it yields the first scientifically-backed evidence of a dinosaur`s colour, which eases dependence on "artist`s impressions" of these enigmatic beasts.

"When I teach my students about dinosaurs, I always say we can learn about feeding, locomotion, reproduction, egg-laying and all that sort of thing," said lead palaeontologist Mike Benton of Bristol University, western England.

"The two things we don`t know and never will know, are about the noises they could make and the colours they were. Well, we`ve now discovered evidence that can tell us for sure some aspects of colour in dinosaurs."

The study, published in the British science journal Nature, looked at spectacular fossils recovered in former lake sediments in Liaoning province, northeastern China.

Since the 1990s, this area has been a treasure trove of dinosaur remains, especially small theropods -- two-footed carnivores -- that are believed to have been the forerunners of birds.

The scientists looked at a specimen of Sinosauropteryx, a bristle-covered theropod about the size of a labrador dog, and an early bird called Confuciusornis.

Their quest was the imprint of melanosomes, which are tough, pigment-carrying components found in the cells of feathers and mammal hair.

With the help of electronic microscopes that scrutinised the bristles to a millionth of a metre, Benton`s team found the telltale outlines of two kinds of melanosomes, one sausage-shaped, the other spherical.

Called eumelanosomes and phaeomelanosomes, they carry pigments that give black and grey, and shades of brown ranging from light beige to ginger.

Confuciusornis had patches of white, black and orange-brown colouring, the paper surmises. Areas where there were no melanosomes on the fossils were presumed to be white.

Benton described this portrayal as a "minimum palette," as feathers have other hues that are not preserved in melanosomes. The chance of determining the colour of dinosaur skin, which does not preserve melanosomes, is "slight," he added.

Palaeontologists have battled over whether theropods could have been the template for birds, of which the first acknowledged specimen, Archaeopteryx, lived around 150 million years ago.

Some argued theropod bristles were primitive feathers, which developed into full plumage, with specialised types, over millions of years. Others retorted the bristles were simply pieces of skin or other preserved tissues.

"These bristles really are feathers," said Benton. "If there were bits of skin or connective tissue or something else, they would not contain melanosomes, full stop."

Another big debating point has been this: why did dinosaurs grow feathers? Were they for flight, for keeping warm or for display, to court or scare off predators?

"We now know that feathers came before wings, so feathers did not originate as flight structures," said Benton.

"We therefore suggest that feathers first arose as agents for colour display and only later in their evolutionary history did they come useful for flight and insulation."

The eight scientists which carried out the research included Xing Xu of the Chinese Academy of Sciences, arguably the most famous fossil hunter alive today.

Bureau Report

First Published: Thursday, January 28, 2010 - 09:06
comments powered by Disqus