Fossils discovered in north China have revealed the existence of giant fleas dating back to the mid-Jurassic era, when dinosaurs still lived on Earth, according to a report published Thursday on the website of the scientific journal Nature. The fossils date back as far as 165 million years, making them the oldest known evidence of fleas, according to Huang Diying, a scientist conducting research on the fossils. Huang is a fellow with the Nanjing Institute of Geology and Palaeontology under the Chinese Academy of Sciences. He led a study of the nine fossils, which were gleaned from north China\'s Inner Mongolia Autonomous Region and Liaoning Province. He said the ancient fleas were as long as 2 cm, while modern fleas are typically 1 to 3 mm long. \"Ancient fleas had stiff bristles, strong claws and longer blood siphons, allowing them to suck blood from dinosaurs,\" Huang said. He said ancient fleas did not have the powerful hind legs seen on modern fleas, although their flat bodies made it easy for them to latch onto a variety of animals.