First Blood-engorged Mosquito Fossil Discovered

After a slew of false alarms, researchers say they have uncovered the first fossilized mosquito bloated with the blood of another animal.

Discovered in northwestern Montana, the 46 million-year-old specimen was uncovered 30 years ago by an amateur fossil hunter. After decades of collecting dust in a basement, it was rediscovered by a biochemist named Dale Greenwalt while he was in the West collecting fossils for the Smithsonian Museum of Natural History.

According to Greenwalt, the fossil stood out from among the others due to its dark, opaque abdomen.

"I immediately noticed it -- it was obvious that it was different," he said in a statement.

Tests revealed a large amount of iron in the abdomen, indicative of blood, while an analysis using a secondary ion mass spectrometer revealed heme, the compound responsible for blood cell's color, among other things.

Unlike Michael Crichton's version of the story, this blood-engorged mosquito was found in stone, not amber, and isn't old enough to contain dinosaur blood. Even if it were, the researchers note, DNA degrades far too quickly for any kind of Jurassic Park-like reenactment, with a recent study suggesting that DNA has a half-life of just 521 years even under ideal conditions. Furthermore, for scientists to assemble a full genome from DNA fragments, they would need a clear picture of what that entire genome looks like -- something they do not have in this case.

Still, the fossil is intriguing, according to the study published in the Proceedings of the National Academy of Sciences, as it offers the oldest direct evidence of blood-sucking behavior. Prior to the discovery, the closest thing researchers had was a mosquito dating back between 15-20 million years with remnants of the malaria parasite in its stomach, offering indirect evidence the creature fed on blood. Finally, the discovery provides the first evidence that biological molecules like heme are able to survive as part of the fossil record.