What can you tell from a heap of bones?

When paleontologists dig up bones they get bits and pieces - some complete bones, often mere fragments. Very rarely, they will find a complete skeleton. These pieces of the jigsaw need to be combined and from them the story of the animal told.

There is much which is purely speculation - the skin type, colour, behaviour - yet other aspects of the animals life can be assessed with reasonable certainty. The diet is part of that more certain ground. The skull is the key to the solution.

What about the largest marsupial (pouched mammal) which ever lived? Can we know what the diprotodon ate?

Owen's Diprotodon

It was the great British biologist, Richard Owen, who coined the term 'dinosaurs'. He founded the British Museum of Natural History, designing the building in which it now stands in Kensington, London. The diprotodon skeleton shown in the Museum of Melbourne, is fully reference scientifically as the Diprotodon optaum (Owen, 1838).


The skull of Diprotodon optaum (Owen, 1838).
It was Richard Owen, who will feature further in the Evolution wars, who scientifically described and named the fossil remains sent from Australia. Not only did he name and describe the dinosaurs, he was the world's leading light in popularising their astounding size and features. Yet he remained a staunch creationist all his life. It was not stupid people who opposed Darwin's revolutionary ideas. Opposition came from some of the greatest minds of the time.

Skulls of mammals can be distinguished by various features including:

* a special ability to chew.

* socketed differentiated teeth which appear in 2 generations of teeth - milk teeth and then adult teeth.

* a single nasal opening leading to nasal cavity.

* a large crania cavity for the brain.

Differences between carnivores and herbivores

In studying a dinosaur skull, the features which help tell if the animal ate meat, or lived on a plant based diet, include these indicators:

* carnivore eyes face forwards to hunt for prey.

* herbivore eyes face out to the side to keep a watch for predators.

* carnivores have large sagittal crests (a central ridge) on their skulls to aid large muscle attachments in the jaw.

* a space between the teeth, where canines would be in a carnivore, is distinctively empty in a herbivore jaw.

* carnivores have well developed canine teeth.

a sheep skull
By studying the available skulls of carnivores and herbivores - such as the skulls of dogs and sheep - scientists, back when dinosaur skulls were first being unearthed, knew the differences in the shape of the skull and the teeth structure.
Dog skulls



The term 'canine teeth' comes from the prominent pointy teeth.
Tyrannosaurus rex skeleton at the Smithsonian museum of Natural History

Photo by Quadell

A hypothetical situation

You are Richard Owen, sitting in your museum in London. You have been sent the skulls of the diprotodon and T-rex.

You are taking these two skulls to a school room full of British school children at the early part of the Nineteenth Century. You are going to describe these two amazing finds to kids who know only of dogs and cats.

Describe the two skulls and explain to the students what they are and how you know what each of the animals ate.

Remember - your audience knows nothing of dinosaurs and digging up the past. Australia is still New Holland and the T-rex skull comes from North America, still  a pretty wild and far off place.

Give your young audience some idea of what these skulls are and what new knowledge they are imparting to the world of science.