Washington: Palaeontologists claim to have discovered the world`s oldest fleas, dating back to 40 million years, which were big in size and might have fed on dinosaurs.
Fleas are hardly preserves as fossils like other ectoparasitic insects. Therefore, the evidence suggesting the origin and early evolution of fleas has been lacking so far. Not any more.
Now, a team, led by Professor Huang Diying from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, says it has found several giant fleas from Middle Jurassic Daohugou biota at Ningcheng Couty in Inner Mongolia and the Early Cretaceous Jehol biota at Beipiao City in China.
The palaeontologists claim the findings provide new insights into the origin and early evolution of fleas and the adaption of hosts. These findings traced back the earliest occurrence of fleas at least for 40 million years.
These Mesozoic fleas are of great body sizes, approximately 15 mm in length, and some longer than 20 mm. As the extant fleas, the ancient females are larger than males.
New Mesozoic fleas with very long piercing mouthparts suggest a resemblance to some Mesozoic siphonate mecopteran, which supports the hypothesis that fleas are derived from Mecoptera, say the researchers.
By contrast the Tarwinia, the new Middle Jurassic and Early Cretaceous fleas armed with various ctenidia on legs and numerous posteriorly-directed setae on abdomen, indicating an adaption to hosts with hairs or furs.
Nevertheless, the long siphon of fleas is obviously able to pierce the skin of feathered dinosaurs, so this is also a possibility, the palaeontologists say in a release by the Chinese Academy of Sciences.
The findings have been published in the `Nature` journal.