In an article called “Hemoglobin-derived porphyrins preserved in a Middle Eocene blood-engorged mosquito” in Proceedings of the National Academy of Sciences, the authors describe “the fossil of a blood-engorged mosquito in oil shale from northwestern Montana.”

“The existence of this rare specimen extends the existence of blood-feeding behavior in this family of insects 46 million years into the past,” they write.

The researchers were able to identify hemoglobin blood using mass-spectrometry analysis. Although DNA molecules cannot survive fossilization, others can survive and can provide information relative to the mechanisms of the fossilization process.

According to the authors, “The abdomen of the fossil mosquito was shown to contain very high levels of iron, and mass spectrometry data provided a convincing identification of porphyrin molecules derived from the oxygen-carrying heme moiety of hemoglobin. These data confirm the existence of taphonomic conditions conducive to the preservation of biomolecules through deep time and support previous reports of the existence of heme-derived porphyrins in terrestrial fossils.”

Read more at:

– Hemoglobin-derived porphyrins preserved in a Middle Eocene blood-engorged mosquito

– Blood-filled mosquito is a fossil first

– Fossilized Mosquito Blood Meal

– Rare, blood-engorged mosquito fossil found

– The 46-million-year-old meal: Scientists discover mosquito fossil so well-preserved that it still has blood in its stomach