Oldest fossilised fleas were giant, bloodsucking
NEW YORK: The oldest known fossilised fleas have been unearthed in deposits from the Middle Jurassic and Early Cretaceous periods in China.
The insects, some twice the size of modern fleas, have been dated to between 165 and 125 million years ago. Based on their anatomical features, they appear to be a mishmash of two different types of insect - fleas as we know them, and a type of insect called a scorpianfly, thought to predate these ancient fleas.
Their combination of modern flea features, including claws needed to grab onto fur, and scorpianfly features, including large, exposed genitalia, suggests that modern fleas may have descended from scorpionflies, the researchers said in paper published in Nature today.
"Scorpionflies and fleas don't look that much alike, but there were times when the distinction between the two was unclear," said co-author Michael Engel, an entomologist at the University of Kansas in the U.S. "Everyone is talking about where the linking fossils between disparate groups are - the fossil record does reveal evolutionary transitions and shifts."