An island of „dwarf dinosaurs” which was only a theory for 100 years really did exist, scientists announced today.

The idea of the small prehistoric beasts on Hateg Island, Romania, was proposed 100 years ago by the colourful Baron Franz Nopcsa, whose family owned estates in the area.

He found that many dinosaur remains on Hateg were half the size of their close relatives in older rocks in England, Germany, and North America.

The baron’s theory has been tested for the first time by Professor Mike Benton at the University of Bristol, and six other authors from Romania, Germany, and the United States.

The team found that the Hateg Island dinosaurs were indeed dwarfs and not just young dinosaurs.

A favourite theme of evolutionary ecologists is whether there is an „island rule” – where large animals isolated on islands evolve to become smaller.

Three species of the Hateg dinosaurs – the plant-eating sauropod Magyarosaurus and the plant-eating ornithopods Telmatosaurus and Zalmoxes – are half the length of their nearest relatives elsewhere.

The team examined these three dinosaurs, each represented by many specimens. They found no evidence of any large bones such as they would expect to find in their normal-sized relatives.

More importantly, a close study of the bones confirmed that the dinosaurs had reached adulthood so they were not just underdeveloped youngsters.

Detailed studies by Martin Sander in Bonn and his students also show that the bone histology (the microscopic structure) is adult.

The idea of „island dwarfing” is well-established in other cases. There were dwarf elephants on many of the Mediterranean islands during the past tens of thousands of years.

These well-studied examples suggest dwarfing can happen quite quickly, the team believes.

Professor Benton, a palaeontologist, said: „The general idea is that larger animals that find themselves isolated on an island either become extinct because there is not enough space for a reasonably-sized population to survive, or they adapt.

The Hateg dinosaurs date from close to the end of the Cretaceous period, some 65-70 million years ago, when much of Europe was flooded by great seas.

There was an archipelago of islands across eastern Europe and the Mediterranean coastal area. Dinosaurs are known to have inhabited some of these.

Hateg Island was about 50,000 square miles and was rich with fossil plants, insects, fishes, frogs, lizards, birds, and mammals, but it is not known exactly how the dinosaurs came to be living on island.

Pof Benton added: „It’s not certain whether they were marooned there as the seas rose, or whether they swam or drifted there by chance later on.

The detailed paper, Dinosaurs And The Island Rule: The Dwarfed Dinosaurs From Hateg Island, is published online today.

Read the article on Metro Cafe

Island of dwarf dinosaurs really did exist

An island of „dwarf dinosaurs” which was only a theory for 100 years really did exist, scientists announced today.

The idea of the small prehistoric beasts on Hateg Island, Romania, was proposed 100 years ago by the colourful Baron Franz Nopcsa, whose family owned estates in the area.

He found that many dinosaur remains on Hateg were half the size of their close relatives in older rocks in England, Germany, and North America.

The baron’s theory has been tested for the first time by Professor Mike Benton at the University of Bristol, and six other authors from Romania, Germany, and the United States.

The team found that the Hateg Island dinosaurs were indeed dwarfs and not just young dinosaurs.

A favourite theme of evolutionary ecologists is whether there is an „island rule” – where large animals isolated on islands evolve to become smaller.

Three species of the Hateg dinosaurs – the plant-eating sauropod Magyarosaurus and the plant-eating ornithopods Telmatosaurus and Zalmoxes – are half the length of their nearest relatives elsewhere.

The team examined these three dinosaurs, each represented by many specimens. They found no evidence of any large bones such as they would expect to find in their normal-sized relatives.

More importantly, a close study of the bones confirmed that the dinosaurs had reached adulthood so they were not just underdeveloped youngsters.

Detailed studies by Martin Sander in Bonn and his students also show that the bone histology (the microscopic structure) is adult.

The idea of „island dwarfing” is well-established in other cases. There were dwarf elephants on many of the Mediterranean islands during the past tens of thousands of years.

These well-studied examples suggest dwarfing can happen quite quickly, the team believes.

Professor Benton, a palaeontologist, said: „The general idea is that larger animals that find themselves isolated on an island either become extinct because there is not enough space for a reasonably-sized population to survive, or they adapt.

The Hateg dinosaurs date from close to the end of the Cretaceous period, some 65-70 million years ago, when much of Europe was flooded by great seas.

There was an archipelago of islands across eastern Europe and the Mediterranean coastal area. Dinosaurs are known to have inhabited some of these.

Hateg Island was about 50,000 square miles and was rich with fossil plants, insects, fishes, frogs, lizards, birds, and mammals, but it is not known exactly how the dinosaurs came to be living on island.

Pof Benton added: „It’s not certain whether they were marooned there as the seas rose, or whether they swam or drifted there by chance later on.

The detailed paper, Dinosaurs And The Island Rule: The Dwarfed Dinosaurs From Hateg Island, is published online today.

Read the article on Metro Cafe

Postat de pe data de 31 ian., 2010 in categoria România în lume. Poti urmari comentariile acestui articol prin RSS 2.0. Acest articol a fost vizualizat de 1,070 ori.

Publica un raspuns