Fossil mosquito containing blood discovered. We’re a long…

Fossil mosquito containing blood discovered.

We’re a long way from Jurassic Park, or even cloning a mammoth, but a 46 million year old Eocene fossil found thirty years ago by an amateur collector and donated to the Washington National Museum of Natural History has been discovered to contain traces of its sanguinous last meal in its abdomen.

Surprisingly the female insect was not found preserved in amber, but in an oil shale formation from northern Montana. This is a first for palaeontology, and should pave the way for a fascinating study into Eocene biochemistry, though the age is too young to contain any dino blood (but it might come from one of their close descendants the birds).

Analyses showed the presence of iron, heme and porphyrin (essential constituents of haemoglobin, the protein that carries oxygen around the body in vertebrate blood) in the mosquito’s abdomen, though any DNA that was once present has long since degraded into illegibility (its inferred lifespan is about 1.5 million years). They were not present in a fossilised male mosquito from the same location. While fossil fleas and mosquitoes have already been found, this is the first to conserve irrefutable biochemical remnants of its blood eating habits.

The survival of such a delicate structure as an engorged mosquito abdomen through the process of the original lake sediments turning into rock (called diagenesis) is in itself extraordinary. Nothing this clear has been found in amber, partly due to the chemical changes that take place as tree sap ages into amber.

It is the first accepted geochemical proof that insects started eating blood a long old time ago, and plagued other lifeforms for tens of millions of years longer than they have us. The survival of porphyrin through 46 million years also tells us about the potential geological lifespan of such organic molecules. It also substantiates controversial claims made by Mary Schweitzer regarding preservation of haemoglobin in dinosaur bone.

Dale Greenwalt’s team published their discovery this week in the Proceedings of the National Academy of Sciences.

Loz

Image credit: The National Museum of Natural History, Washington

http://www.nature.com/news/blood-filled-mosquito-is-a-fossil-first-1.13946

http://www.csmonitor.com/Science/2013/1015/46-million-year-old-mosquito-filled-with-blood-is-a-scientific-first-video

http://news.discovery.com/earth/rocks-fossils/rare-blood-engorged-mosquito-fossil-found-131015.htm

Original paper. paywall access: http://www.pnas.org/content/early/2013/10/08/1310885110