Dinosaurs - Sinosauropteryx prima

Introduction

Sinosauropteryx prima was a small, meat-eating dinosaur that lived about 125 million years ago. It was covered with delicate, hair-like feathers.

Identification

Sinosauropteryx prima had:

• long legs, short arms with three fingers, a bony tail and sharp teeth;
• primitive feathers (up to 3 cm long, covering most of its body) that probably helped it to keep warm;
• a long tail that it used for balance as it ran on its hind legs;
• a probable diet of lizards, insects and small mammals.

Fossils description

Sinosauropteryx prima was discovered by farmers near Sihetun village in Liaoning Province and described in 1996. Its name means 'first Chinese dragon feather' in reference to the fact that this Chinese fossil was the first non-avian (or 'non-bird') dinosaur found with feathers.

The discovery of Sinosauropteryx prima in 1996 was one of the most important fossil finds of the century. It was the first non-avian dinosaur found with feather-like structures, providing further evidence for the link between dinosaurs and birds. Its name means 'first Chinese lizard wing'.

In a 2010 paper published online in Nature, a team of scientists from China and the UK revealed that Sinosauropteryx probably had ginger-coloured feathers and a striped tail.

The team first studied fossils of an ancient bird Confuciusornis (which lived during the Cretaceous) by using an electron microscope to look inside the feathers for microscopic structures called melanosomes. In living animals, melanosomes contain melanin, a pigment which gives colour to human and animal hair as well as feathers. Different shaped melanosomes produce different colours - blacks or greys are produced by 'sausage-shaped' melanosomes and reddish shades come from spherical ones.

Finding melanosomes in Confuciusornis indicated that extinct animals probably also had similar structures for pigmentation, and that similar-shaped structures may have produced colourings like those found in living animals.

Using these results, the scientists then analysed Sinosauropteryx. They concluded that the bands of dark and light along the tail were in fact ginger and white stripes - the first evidence of original colour of feathers in dinosaurs.

Evolutionary relationships

Sinosauropteryx prima was a small theropod called a coelurosaur. It belonged to the family Compsognathidae, which occurred in Europe and China in the Late Jurassic to Early Cretaceous.