INTERNAL ANATOMY HUMAN

After the excitement of all the sporting events that have taken place in London this summer palaeontologists have been reviewing the fossils of one of the oldest English dinosaurs known to science - Hypsilophodon. With memories of great long distant races still fresh in the mind, it looks like some dinosaurs could have competed with the very best human runners.

However, a new study by scientists, shows that one ancient resident of Great Britain could have given the top sprinters and the very best middle distance competitors a run for their money.

A Common Dinosaur in the Cretaceous of Europe

Hypsilophodon remains are relatively common in Lower Cretaceous strata of both Europe and America. The Hypsilophodonts were a highly successful group and a number of superbly preserved fossil specimens are known. This animal was named and described in 1869. At the time of its formal classification, British Zoologist Thomas Huxley commented that with its five-fingered hands and light body this dinosaur could have lived in trees. A number of illustrations were made of this arboreal dinosaur and depictions of Hypsilophodon sitting comfortably on a conifer branch can be found in many old dinosaur text books from the 1970s and 1980s.

Dermal Armour to Protect Against Dinosaur Attacks?

Previous descriptions of Hypsilophodon fossils describe these little plates as components of dermal armour, perhaps a double row of plates running down the spine. Now Butler and his associates have a different explanation for the finding of these items with fossils of this particular dinosaur. The team noted that the plates were weakly constructed and overlaid but were not actually fused to the ribs. Butler explained the previous interpretations by saying that as the carcase of a Hypsilophodon rotted the bones from the skin would become jumbled up with internal bones. However, the team's careful analysis and mapping of the fossil material shows that the bony plates are always closely associated with the outside surface of the ribs from the front end of the ribcage.

Natural History Museum Scientists Analyse the Fossil Bones

The Natural History Museum scientists believe the plates were similar to the bony structures referred to as "uncinate processes," seen in the rib-cages of many modern birds. Although it is not clear whether dinosaurs had the same breathing systems as birds. Since this feature is involved in bird ribcage support, facilitating movement and breathing, the scientists now suspect the structures played a similar role in the dinosaur.

The British team have suggested that because evidence for similar mineralised plates has been detected in other dinosaur skeletons, the researchers further theorise that all small-bodied, bird-footed dinosaurs possessed these structures.

Darren Naish, of the University of Portsmouth's School of Earth & Environmental Sciences, is also intrigued by the fact that the structures could be "widespread, possibly even universal" in other small, herbivorous dinosaurs.

The popular science writer and palaeontologist commented that when the academic old papers are examined there are several mentions of bony plates being found in association with Hypsilophodontid skeletons. None of the papers actually infer any connection with efficient breathing however. Sometimes a fresh look at old fossil material may reveal some surprises.