Jurassic age cleaners

125 million-year-old fossil suggests cockroaches ate dinosaur dung

By Megha Prakash
Published: Wednesday 15 January 2014

A cockroach fossil trapped in tree resin has been found in Lebanon

COCKROACHES are known for their ability to adapt and survive. Over 100 million years ago, in the era of the dinosaurs,ÔÇêthey survived by feeding on dinosaur dung.

During most of the Mesozoic era (252-266 million years ago), dung beetles and flies, which generally clean up faeces, were rare. A study suggests that the function of cleaning up at that time was being done by cockroaches.

Researchers from Slovakia, Russia, Lebanon and Japan studied a 125 million-year-old fossil of a cockroach found in Lebanon. It belonged to the now extinct Blattulidae family. The immature cockroach was found trapped in tree resin in a forest. Trying to escape, it defecated and left five coprolites still extruding from the body. When the researchers studied the fossil using a synchrotron X-ray microtomography, to figure out the cockroaches’ diet, they found small pieces of smooth-edged wood particles in its gut.

The researchers postulate that this wood originated from dung—the pieces were smooth—suggesting predigestion. As dinosaurs dominated the period, the researchers say that the wood came from dinosaur faeces. The team has studied roughly 30,000, more or less preserved, specimens from the Blattulidae family.

The study shows that the first insects to process wood might have originated to clean up after dinosaurs, says lead author Peter Vrsansky associated with the Slovak Academy of Sciences and Russian Academy of Sciences.

The study also indicates a relation between modern day termites and cockroaches. The findings suggest that the microorganisms involved in the breakdown of dinosaur faeces would have passed on from these cockroaches to the modern day termites.

However, Srini Kambhampati, chair, department of biology, University of Texas, Tyler, US, saysÔÇêthe evidence that cockroaches may have been feeding on dinosaur faeces is less than convincing. “It seems unlikely that a cockroach would feed on a large piece of wood that it cannot digest. The authors do not consider the possibility that the cockroach in question ate wood. If this was the case,ÔÇêthe cockroach could have excreted smooth, partially digested wood. The authors have drawn pretty broad conclusions based on one fossil specimen and sparse data,” he says.

The paper was published online on December 4 in PLoS ONE.

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