Monster 'Fleas' Put the Bite on Dinosaurs

giant flea plagued dinosaurs — Artist's illustration of a giant flealike insect that plagued dinosaurs 165 million years ago. The bug, *Pseudopulex jurassicus*, used a long proboscis to feed on the blood of dinosaurs.

(Image credit: courtesy of Capital Normal University, Beijing, China)

Paleo-pests about 10 times bigger than today's fleas may have sneaked up on a huge dinosaur, crawled onto its soft underbelly and taken a bite, likely a painful one, say researchers who have discovered fossils of the flealike organisms.

"It would have felt about like a hypodermic needle going in, a flea shot, if not a flu shot," George Poinar Jr., a professor emeritus of zoology at Oregon State University, said in a statement. "We can be thankful our modern fleas are not nearly this big," said Poinar, who wrote a commentary alongside the research article published online April 24 in the journal Current Biology.

Latest Videos From

Watch full video here:

This large body size as well as the long, serrated mouthparts "for piercing tough and thick skin or hides of hosts suggest that these primitive ectoparasites might have lived on and sucked the blood of relatively large hosts, such as contemporaneous feathered dinosaurs and/or pterosaurs or medium-sized mammals, found in the Early Cretaceous, but not the Middle Jurassic," Shih wrote in an email to LiveScience.

To find out which dinosaurs may have needed flea collars, the team surveyed information on coexisting animals that lived at the same time and place as these insects. During the middle Jurassic, potential feathered-dinosaur hosts may have been Pedopenna daohugouensis and Epidexipteryx hui. During the early Cretaceous, when P. magnus lived, Sinosauropteryx prima and Microraptor gui may have served as hosts, Shih noted.

Jeanna Bryner is managing editor of Scientific American. Previously she was editor in chief of Live Science and, prior to that, an editor at Scholastic's Science World magazine. Bryner has an English degree from Salisbury University, a master's degree in biogeochemistry and environmental sciences from the University of Maryland and a graduate science journalism degree from New York University. She has worked as a biologist in Florida, where she monitored wetlands and did field surveys for endangered species, including the gorgeous Florida Scrub Jay. She also received an ocean sciences journalism fellowship from the Woods Hole Oceanographic Institution. She is a firm believer that science is for everyone and that just about everything can be viewed through the lens of science.