The bugs may have evolved to exploit the expansion of feathered dino saur s and early birds. One feather shows signs of significant gnawing damage, suggesting that lice had established feather feeding lifestyles in the mid-Cretaceous. The ancient bugs have different antennae and leg claws from a modern louse, but their wingless bodies look similar, and they feature the large chewing mandibles that cause so much irritation to their hosts. But the insects in question, Mesophthirus engeli, appear as a primitive species very much resembling modern lice. The bugs may not technically be lice, as their taxonomical relationship to the louse order Phthiraptera is unknown. “It’s almost like a lottery game, where you win once in a while. During five years of studying amber samples these two were the only ones found to contain the lice-like insects. Each feather was encased in amber some 100 million years ago in what is today the Kachin Province of northern Myanmar. Shih and colleagues found ten, tiny insect nymphs, each less than 0.2 millimeters long, distributed on a pair of feathers. Consequently, early forms of lice and their evolutionary history have remained a mystery to scientists. The earliest bird louse previously known lived in Germany some 44 million years ago, and by that relatively late date the insect had become nearly modern in appearance. Scientists are not yet sure, however, if the species belongs to the same taxonomical order as modern lice, Phthiraptera. The ancient parasitic insect, Mesophthirus angeli, resembles modern lice, with slightly different antennae and leg claws. The Cretaceous period’s lice-like insects are so small that they have not been found preserved in other fossils. While it stands to reason that feathered dinosaurs were plagued by lice-like insects just as their living bird descendants are, the newly discovered insects encased in amber are the first example to emerge in the fossil record. The supersized fleas gorged on the blood of Jurassic-period dinosaurs some 165 million years ago. In 2012, CNU researchers reported a new family of huge, primitive fleas-more than two centimeters (three-fourths of an inch) long-that survived for millions of years in northeastern China. Studying the ancestors of living ectoparasites, which live on the outside of their hosts, can help scientists understand how these pests evolved over millions of years into the species that live among and on us today. “In human history you can see that the flea caused the black plague, and even today we are affected by blood sucking or chewing parasites,” Shih says. Though small in scope, parasitic insects have caused enormous suffering by spreading modern diseases like the plague and typhus. The scientists are fascinated by insects that spent their lives sucking the blood, or gnawing the skin, hair and feathers of their much larger hosts. While dinosaurs may garner an outsized share of attention, the tiny prehistoric pests and parasites that lived on them are a particular specialty of Shih and colleagues at Capital Normal University (CNU) in Beijing. Mesophthirus angeli crawling on the dinosaur feathers in mid-Cretaceous amber. “The preservation in amber is extremely good, so good it’s almost like live insects,” says Chungkun Shih, a paleoentomologist and co-author of a study detailing the new find in Nature Communications. The bugs provide paleontologists’ first glimpse of ancient lice-like parasites that once thrived on larger animals’ feathers and possibly hair. Scientists examining amber fossils discovered 100-million-year-old insects preserved with the damaged dinosaur feathers on which they lived. As far back as the Cretaceous period, insects that resemble modern lice lived and fed on the bodies of dinosaurs. But humans are far from the first animals to suffer at the expense of these hair- and feather-inhabiting parasites. Anyone who’s had to deal with a lice infestation knows how annoying the persistent little pests can be.
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