Fleas and Lice

A warm rain had caused tens of thousands of termites to swarm out of a nest at the base of a rotting log, and a feathered juvenile theropod, a coelurosaur was frantically rushing after them, savoring their rich, fatty bodies. After leaping into the air to snap at those that had just become airborne, the youngster suddenly stopped and began frantically scratching among the feathery structures on his neck. Residing there were two species of strange, wingless insects. One, a large, partially flattened louse almost a half-inch in length, remained fairly quiescent between the feather bases close to the skin surface. From time to time, the creature's vertical mandibles scraped away and devoured some of the epidermis, which served as its major food source. This giant louse was one of many that lived here, and the resulting irritation from their bites had caused the dinosaur to stop and claw at the itchy infested area. But the disturbance only made the primitive lice extend flattened antennae and secure themselves more firmly to the host.

A second, somewhat smaller parasite living in the downy plumage of the small coelurosaur had inserted a short, sturdy beak into the animal's skin and was sucking up blood. This primitive flea had stretched out monstrous hind legs and used them to grasp the feather bases for stability. Earlier, these same muscular legs had been employed to propel the flea onto the victim's body. A series of other appendages protruding from the abdomen provided additional attachment. An entire community of fleas and lice infested the youngster, having crawled aboard when he hatched, and succeeding generations would continue to reside there until his death.

Parents cringe when their child brings a note from school informing them that a lice infection has been detected in the classroom and their child needs to be treated. And pet lovers know all about the astonishing jumping abilities of fleas and their painful, itching bites. Such pests have followed us into urban communities, and even with all our efforts to control them, still manage to plague us. Think how primitive man must have suffered!

Where would these pests have occurred on dinosaurs? A reasonable location would be among the plumage of feathered dinosaurs. Fleas and lice thrive under the protection of hairs and feathers on both mammals and birds. Plumed dinosaurs such as Sinosauropteryx, a small coelurosaur, were probably ideal hosts for early fleas and lice.

While modern fleas can be enticed to take blood from lizards,219 they do not seek out reptiles in nature, probably because there is little place for concealment. However, flea-like creatures have been described from the Mesozoic that could have attacked ancient reptiles. One of these is the outlandish Strashila, equipped with crab-like claspers and long claws.104 This small creature had extremely powerful hind legs that dwarfed the rest of the body (fig. 21). We sometimes are able to surmise the habits of extinct organisms by their structural characters, a principle known as functional morphology. A robust beak indicated that Strashila may have sucked blood, and clasping processes on the hind legs might have been used to grip feathers. It was suggested that these creatures sucked blood from pterosaurs, but they could just as well have attacked feathered dinosaurs. This bizarre lineage probably became extinct sometime in the Cretaceous.

Another bewildering Mesozoic flea-like insect is the large-bodied Saurophthirus. Their prolonged proboscis, extended claws, and long legs have been considered modifications for feeding on pterosaur wings.221222 The peculiar legs also could have been

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