Evolution Diary

Scientists continue to learn more about Thecodontosaurus

New research into the Bristol dinosaur Thecodontosaurus suggests it lived on subtropical islands around the city and not in a desert.

A microscopic study of marine algae and fossil pollen revealed the dinosaur lived just before the Jurassic Period in lushly vegetated islands.

It had been thought the dinosaur lived in the arid uplands of the late Triassic Period.

The original dinosaur was discovered in 1834 near what is now Bristol Zoo.

The findings could also explain the dinosaur’s size (2m) in relation to its mainland equivalent, Plateosaurus (10m).

Thecodontosaurus  is one of the earliest named dinosaurs. When its bones were first discovered dinosaurs were not recognised as a group.

In 1975, the remains of at least 11 other individual dinosaurs were uncovered in a quarry at Tytherington, north of Bristol.

Dr David Whiteside, an authority on extinct reptiles at the University of Bristol, and Professor John Marshall, an expert on fossil pollen at Southampton University, collaborated on the research project.

Dr Whiteside said: “This is a unique equal collaboration between a palaeontologist specialising in pollen grains, which are microfossils, and a vertebrate palaeontologist working on Triassic reptiles.

“I can’t think of any other scientific paper where the two specialisms were combined to produce a complete paleoenvironmental model which includes the whole community of land animals showing the time and habitat they lived in and how they died.”

Small territory

Professor John Marshall said: “The big surprise was discovering that these reptiles did not live on arid uplands but rather on small well-vegetated tropical islands around Bristol about 200 million years ago.

“It is only the microfossil pollen and algae that can tell us this. The outlines of the islands can still be seen today in the shape of the land.”

Thecodontosaurus bones have been discovered on both Cromhall Island, north of Bristol, and Failand Island, part of which is in the city of Bristol and a short distance inland from the present coast.

Geological mapping indicates that the islands the dinosaurs lived on were quite small in size.

The discovery that the Bristol dinosaur lived on very small islands is very important as most researchers have believed that it was a primitive member of the prosauropods, which included some very large animals and existed before the huge sauropods, such as Diplodocus of the Jurassic Period.

The study is published in Geological Magazine.

News reposted from BBC