Fossilized female mosquito in a paper-thin piece of shale. The 46 million year-old insect drew blood in its last meal, was blown into a lake in what is now northwestern Montana and sank, belly still full. It’s a first for biology, a blood meal found intact in a fossil. [ source ]
PHOTO CREDIT: Dale Greenwalt / Smithsonian
Blood-Engorged Mosquito Fossil Found
Said to be a First in Paleobiology
Source: Dale Greenwalt (National Museum of Natural History)
via Douglas Main, LiveScience | October 14, 2013
About 46 million years ago, a mosquito sunk its proboscis into some animal, perhaps a bird or a mammal, and filled up on a meal of blood. Then its luck turned for the worse, as it fell into a lake and sunk to the bottom.
Somehow, the mosquito didn’t immediately decompose and became fossilized over the course of many years.
Dale Greenwalt — a retired biochemist who collects and analyzes insect fossils from Montana for the Smithsonian Institution — discovered the mosquito fossil after it was given to the museum as a gift, and he immediately realized the rarity of a blood-engorged mosquito fossil.
The specimen was examined using time-of-flight secondary ion mass spectrometry, an analytic technique that doesn’t destroy the sample being examined.
The female mosquito’s belly was full of iron. Iron levels were higher than elsewhere in her body and than anywhere on a non-biting male used as a control subject. Then the team found evidence of porphyrins, which are bound to iron in blood. Putting the two together makes “a definitive case” for blood, Greenwalt said.
Researchers don’t know what kind of animal the blood came from, since such porphyrins don’t differ among different animals.
While the scenario sounds eerily similar to the Michael Crichton book and movie “Jurassic Park,” no new T. rexes will result.
This mosquito flew long after dinosaurs went extinct. Moreover, scientists have long known that DNA from other organisms cannot survive in insect fossils.
(via LiveScience and AP / Miami Herald)