Glossary

Predatory animals

These are the carnivorous animals - flesh eaters.

Prey animals

These are the animals that get eaten by predators. Note that predatory animals can get eaten by other predators and hence become prey as well.

A division in the biological grouping (taxonomic grouping) of creatures. All animals belong to a species and each species belongs to a larger group (a genus) and so on. Here is a list of the groups (smallest first) and an example classification (of a wolf).

species	lupus
genus	canis
family	canidae
order	carnivora
class	mammalia
phylum	chordata

Vascular system

The vascular system is the series of vessels or spaces that transport fluids round the body. In the case of bone, the spaces we see are mainly used as blood-vessels, to transport blood through the bone. Highly vascular bone has more of these vessel spaces.

Osteons

You could consider an osteon to be a building block of bone. It is composed of a series of concentric rings of bone cells and bone matrix, surrounding a hole in the middle which is filled by blood-vessels and nerves. The first lot of osteons to be deposited are kown as primary osteons and if they are replaced by new growth, the new osteons are called secondary osteons.

Impermeable

An impermeable substance does not let liquid, e.g. water, pass through it.

Endotherm

An animal that makes use of endothermy.

Ectotherm

An animal that controls its temperature using ectothermy.

Theropod

A type of saurischian dinosaur. Theropods were carniverous and walked on two legs.

Organic

All organic compounds contain the element carbon. Bone is composed of two parts - inorganic crystals and organic collagen (a complex protein). The organic part of bone gives it its flexibility and the inorganic part provides strength.

Saurischia

One of the two major groups (orders) of dinosaurs.

For more information on groups within the dinosaurs click here.

Ornithischia

One of the two major groups (orders) of dinosaurs.

For more information on groups within the dinosaurs click here.

Oxygen isotopes

Oxygens exists in three different isotopic forms - with different numbers of neutrons. The most commonly occuring isotopes are 18O and 16O. The ratio of these two isotopes, compared with a standard value, is what has been referred to as the oxygen isotope value.

Mass homeothermy

Click here to find out more.