May 2, 2012
Prehistoric Flea-Like Insects Were A Mean Bunch
Illustration by Wang Cheng, Oregon State University
Massive flea-like insect fossils discovered by Chinese scientists are believed to be the oldest of their kind, and may have feasted on dinosaurs some 165 million years ago, according to zoologists who analyzed the creatures.
The fossils were discovered in Inner Mongolia by a group of Chinese scientists, and recently announced in the journal Current Biology.
The blood-sucking pests, which are similar to fleas, are more likely part of a separate and now extinct lineage, said George Poinar Jr., an insect expert and zoology professor at Oregon State University who wrote a commentary on the fossil finds. These nasty critters were likely 10 times larger than a flea you would find on your pet today, he added.
“These were insects much larger than modern fleas and from the size of their proboscis we can tell they would have been mean,” said Poinar. “You wouldn´t talk much about the good old days if you got bit by this insect. It would have felt about like a hypodermic needle going in — a flea shot, if not a flu shot. We can be thankful our modern fleas are not nearly this big.”
Called Pseudopulex jurassicus and Pseudopulex magnus, these insects had bodies that were flatter than those of modern fleas, like a bedbug or tick. They had long claws that could reach over the scales on a dinosaur´s skin, so they could hold on tightly while feeding. Modern fleas are taller and thinner, with shorter antennae, and can move quickly across the furred and feathered bodies of their victims.
“These are really well-preserved fossils that give us another glimpse of life into the really distant past, the Cretaceous and Jurassic,” Poinar said.
True fleas, like those around today, feed on warm-blooded vertebrates, explained Poinar. Today, 94 percent of the 2,300 known species attack mammals, while the rest attack birds. But the unusual characteristics of the fossilized specimens lead researchers to believe their prey were some of the largest non-warm-blooded animals to have ever lived.
And unlike today´s fleas, which deliver a little more than an annoying bite, the prehistoric critters may have produced a very painful stinging bite. However, modern fleas have done plenty of damage in their own right -- fleas brought mankind the bubonic plague, which has killed more than 75 million people worldwide.