Home > Lifestyle > Features
Tuesday October 22, 2013 MYT 12:00:00 AM
Tuesday October 22, 2013 MYT 8:06:57 AM
by kerry sheridan
A close-up of the fossil of a blood-engorged mosquito. Researchers do not know what kind of creature provided the blood for her last meal, since DNA is impossible to detect from a sample so old. — AFP/ Smithsonian Institution
A rare mosquito fossil shows female’s blood-filled belly, but forget about getting any DNA from it.
A UNIQUE 46-million-year-old mosquito fossil with a belly full of dried blood has been found in a Montana riverbed, US researchers said.
“It is an extremely rare fossil, the only one of its kind in the world,” said Dale Greenwalt, lead author of the study in the Proceedings of the National Academy of Sciences.
Cutting-edge instruments detected the unmistakable traces of iron in her engorged abdomen, but just what creature that blood came from is a mystery since DNA cannot be extracted from a fossil that old.
Greenwalt said it might have been blood from a bird, since the ancient mosquito resembles a modern one from the genus Culicidae, which likes to feed on our feathered friends.
“But that would be pure speculation,” said Greenwalt, a retired biochemist who volunteers at the Smithsonian Museum of Natural History in Washington.
While far from the oldest known mosquito fossil – that honour goes to a 95-million-year-old mosquito in amber in Myanmar – entomologist Lynn Kimsey of the University of California said it was “a very exciting find”.
Greenwalt said he became fascinated with fossilised insects several years ago.
He learned about Master’s student Kurt Constenius, who described his discoveries of fossilised insects along a remote Montana riverbed in an obscure geological journal more than two decades ago.
Greenwalt and Constenius discussed the fossil grounds, which lie near the Flathead River along the western boundary of Glacier National Park.
The fossil described in the journal came not from Greenwalt’s outings, but from a collection of fossilised insects languishing in Constenius’s basement since the 1980s, and which he and his family had donated to the Smithsonian museum.
“As soon as I saw it, I knew it was different,” Greenwalt told AFP.
The mosquito itself is only about 4.5mm in size. Somehow, the fragile creature ate its last meal, filling its abdomen until it was nearly ready to burst like a balloon.
Then, perhaps as the mosquito was flying over an algae-coated lake, it became caught in that mucus, enveloped in microbes that protected it from degrading, and eventually sank deep into the sediment of the lake.
Experts used a technique called non-destructive mass spectrometry to identify the source of the iron in her abdomen as haeme, the molecular entity that allows haemoglobin to transport oxygen.
The 1993 movie Jurassic Park showed scientists extracting dinosaur DNA from the abdomen of a mosquito trapped in amber.
Not only was the scene fictional – no one has ever been able to extract DNA from a fossil so old – Greenwalt said the mosquito pictured was a male, and male mosquitoes do not feast on blood.
“Like a lot of science fiction, it kind of predicted what we might be looking at in the future,” he said. – AFP
Tags / Keywords:
Science & Technology, Science, fossil, mosquito, blood, DNA
Copyright © 1995-2013 Star Publications (M) Bhd (Co No 10894-D)