Fossilised Fleas Ten Times the Size of a House Flea from the Jurassic

Warning, reading this article may cause irritation. Don’t blame me if you end up scratching your skin as your read this piece. Dinosaurs and fleas, dinosaurs and their parasites, what a combination. Our subject is the evolution of that highly specialised and very successful insect the flea. A number of new studies into the evolution of fleas have taken place recently, with a focus on giant blood-sucking parasites from the Middle Jurassic.

Chinese scientists have been slowly and surely piecing together the origins of the flea family using fossils found in two regions of China, both famous for their dinosaur fossils. Scientists have been “scratching” around in the sedimentary layers of Liaoning Province and in Ningcheng County collecting beautifully preserved, ancient, insect specimens that shed light on the origin and evolution of fleas. They may not be as exciting as a Triceratops or a T. rex but it seems that fleas may have readily adapted to feeding off and living on the Dinosauria as they evolved and diversified. We know that many readers will be just “itching” to learn more about these latest fossil discoveries.

Fleas – Highly Specialised Insects – Very Successful Insects

Fleas are one of the most dramatically specialised of all the families that make up the Order Insecta. They have reduced wings, a laterally-flattened body and specialised mouth parts for feeding on the blood of mainly mammals (including our own species). There are about 2,550 species or sub-species known and they are present throughout the world, even places like the Arctic circle – just ask a lemming. Most fleas are small, usually between 1-3 millimetres in length. Fleas are parasitic insects – insects that feed on other creatures (parasites).

Fleas in the Fossil Record

Like most insects, Fleas are seldom preserved as fossils. Indeed, take away those fossils of insects preserved inside amber and you are left with a disproportionately sparse fossil record for such an important group of Arthropods. Definitive fossil evidence of fleas has been largely confined to fossils of fleas caught in tree sap and preserved as amber. Most of these fossils date from the Cenozoic, from after the time of the dinosaurs, but in one or two exceptional locations fossils of fleas that once plagued the dinosaurs can be found. The evidence suggesting the origin and early evolution of fleas has not been gathered together and studied, there simply were not enough fossils to study – until now. » Read more: Giant Fleas From the Jurassic Sucking the Blood of Dinosaurs