WASHINGTON (AP) — For the first time, researchers believe they have found an intact meal of blood preserved inside a fossil of a mosquito.

A study in the Proceedings of the National Academy of Science says the fossilized female insect was found in a piece of shale, which had sat in someone's basement for 25 to 30 years with other rocks.

Dale Greenwalt, a retired biochemist who analyzes insect fossils from Montana for the Smithsonian Institution, says the research team analyzed what was in the mosquito's belly and concluded it was blood, probably from a bird.

It sounds eerily similar to the Michael Crichton book and movie "Jurassic Park," but Greenwalt says real scientists know DNA doesn't survive in insect fossils.

Outside expert Mary Schweitzer of North Carolina State University says the study is exciting and significant, but preliminary. She also says Greenwalt and his team didn't prove their conclusion that it is blood by ruling out all other possibilities.