Julian Beck, of College St School, asks :-

How many different kinds of dinosaurs are there?

Joan Wiffen, is an amateur palaeontologist who was awarded an honorary DSc from Massey University in 1994 for her work in discovering and excavating bones from several dinosaur in New Zealand. Joan is 72 and self-taught. Raised on a farm at a time when few girls received higher education, Joan discovered the world of biology and fossils through the books she brought to read to her children. She has a wood-boring, bi-valve shell named in her honour. Joan responded.

There is no single list of different kinds of dinosaurs, to the best of my knowledge. Dinosaurs are identified in the usual way, beginning with the Class, Order, Family, Sub-family, Genus and species. Many of the old names in use are invalid because they have been given to inadequate material (a bone or two), or because the name has already been used. There are literally hundreds of different kinds of dinosaurs belonging to approximately 23 families, and more are being discovered every week!

The longest name given to a dinosaur is probably 'Pachycephalosaurus', a 'bonehead' type of hadrosaur found in Montana, U.S.A. The shortest name given to a dinosaur is 'Mimi', and belongs to a nodosaur, found in Queensland, Australia.

The largest meat-eating dinosaur is Tyrannosaurus Rex, typically 14 metres long and 5.6 metres high.

The largest dinosaur discovered, a 52 metre long plant-eater, was called 'Seismosaurus' becaused it was guessed that it the earth would shake like an earthquake when it walked.

The smallest dinosaur is thought to the Compsognathus which was discovered in France. It is the size of a chicken. Embrionic dinosaurs have been found in fossilised eggs.

We have found many isolated dinosaur bones which have been washed down rivers during floods to be buried in marine sediments together with complete skeletons of marine animals. Subsequent sea level changes and geological land upthrust have placed these above sea level today. I have a lot of fun searching for these relics of the earth who lived before humans evolved.