'Extremely Stable' Blood Found in 46-Million-Year-Old Mosquito

Mosquitoes have been annoying humans for hundreds of years, but they have been sucking blood from other animals for far longer, close to 50 million years, say scientists who have ancient blood to prove it. Researchers have found components of blood cells in a 46-million-year-old fossilized mosquito. (Photo : Smithsonian Institution)

This is the first blood-filled ancient fossilized mosquito ever found.

Researchers' report on the fossilized mosquito appeared Monday in the journal Proceedings of the National Academy of Sciences.

"[The paper] shows that details of a blood-sucking mosquito can be nicely preserved in a medium other than amber," paleontologist George Poinar of Oregon State University, who was not involved in this research, told The Scientist.

The insect, with its visibly extended abdomen, was found trapped in oil shale, a sedimentary rock from an ancient lakebed in northwestern Montana

Researchers were surprised to find that the blood had not disintegrated before fossilization set in. The chances of this discovery occurring were very, very small.

Dale Greenwalt, a researcher at the National Museum of Natural History in Washington, D.C., discovered the mosquito fossil after it was given to the museum as a gift, and he immediately realized the specimen's rarity.

Using non-destruction technologies, a team of researchers screened the fossil for a range of compounds, including two components of heme, the protein that transports oxygen in red blood cells.

Among the chemicals they recovered from the fossilized mosquito were iron and porphyrin molecules, which are organic compounds present in hemoglobin, a protein found in blood. This confirmed the iron was from the insect's last meal and not part of the fossilization process.

Unfortunately, it is impossible to tell what kind of animal the blood came from. DNA does not preserve very well - The Sydney Morning Herald notes that DNA cannot survive more than 6.8 million years - and current technology cannot pick out DNA from fossils older than that. The mosquito is from the Eocene epoch, lasting from 56 to 33.9 million years ago - about 19 million years after dinosaurs went extinct.

Unfortunately, that means no real-life "Jurassic Park."

The discovery of the fossilized mosquito with ancient animal blood in it is only the fifth time scientists have come across an insect fossil containing blood, according to IBTimes.

"Most fossils of blood-eating insects that have been found are of midges, a kind of biting fly, trapped in amber," Western Digs notes.

The mosquito preservation recovered from shale, a type of rock that forms from sediments deposited at the bottom of bodies of water is an extremely improbable event.

"The insect had to take a blood meal, be blown to the water's surface, and sink to the bottom of a pond or similar structure to be quickly embedded in fine anaerobic sediment, all without disruption of its fragile distended blood-filled abdomen," the researchers said in the report.

What is shocking is that the sedimentation didn't damage the fragile insect's blood-filled abdomen. 

Mary Schweitzer, a researcher at the North Carolina Museum of Natural Sciences, who was not involved in the study, confessed:

The study is exciting, because it provide more evidence that porphyrins, organic compounds found in "virtually all living organisms from microbes to humans in varying amounts" are "extremely stable" - and are thus a perfect focus for studying long-dead plants and animals.