Dinosaur Camouflage Uncovered by Chromatography?

Fierce, scary and, above all else, pretty massive — dinosaurs ruled the earth for millions of years. But not all of them were big and mighty. In fact, there were many species of dinosaur that were relatively small. The Psittacosaurus is a perfect example. About the size of a large dog, it was considerably smaller than its co-habitants on earth. So how did it survive?

In a world dominated by bigger creatures, it can be difficult to imagine a smaller species lasting too long. It would certainly be going towards the lower end of the food chain. However, scientists have discovered that camouflage might have played a key part in keeping the Psittacosaurus alive.

Ancient pigments

To gather more information about dinosaur species, scientists turn to palaeontology — the analysis of fossils. Previous research suggests that the Psittacosaurus had pigmentation in the form of black specks across its tail and legs. But the reason for this skin colouring is a bit of a mystery. Some scientists think this could merely be decomposition from the animal’s corpse being feasted on, while others suggest it is the remnants of melanosomes.

Melanosomes are responsible for the colour in cells and tissues. The problem is that the fossil melanosomes are often mistaken. Some scientists argue that in a lot of cases microbes are being mistaken for melanosomes. The microbes are preserved in fossils by a biofilm, which means that it can be difficult to distinguish between the two. Microbes and melanosomes overlap visually, and some microbes can even develop into melanin over time, adding further complications to the research.

Digging beneath the skin

Ideally, scientists would have a method of telling the two apart. And chromatography could be the answer, specifically gas chromatography-mass spectrometry (GC-MS) — a method which allows different bacteria to be identified by even the smallest trace. The use of GC-MS is discussed in the article, Adding more Power to your GC-MS Analysis through Deconvolution.

The problem, however, is that samples would be destroyed in the process — a process known as destructive testing. Fossils are totally invaluable for research, giving scientists an abundance of information. So, while chromatography would be a useful tool to use, it looks like the information might have to stay locked away in fossils.

Those who do believe the pigments are melanosomes suggest that the animal’s light belly and dark back was characteristic of camouflage. The part of the body exposed to light — the back — is darkened. This, if true, would have made it much harder to hunt the animal in forest areas, where it is believed to have resided. But with only four fossil samples at their disposal, it’s thought the team may be jumping to conclusions.