An ancient tick with mammalian blood discovered in a piece of amber

Fossil tick in amber (Photo courtesy Oregon State University)
Fossil tick in amber (Photo courtesy Oregon State University)

An article published in “Journal of Medical Entomology” describes the study of a drop of blood that belonged to a mammal that lived tens of millions of years ago preserved in amber. A team led by George Poinar, Jr. of the College of Science at Oregon State University, studied what are the oldest traces of mammalian blood. That blood was sucked by a tick that probably belonged to the genus Amblyomma which was then trapped in amber.

This piece of amber was found in a mine in today’s Dominican Republic. Its age was estimated in different ways based on the presence of other fossils: counting the foraminifera it’s estimated between 15 to 23 million years and counting coccoliths up to 30-45 million years.

Probably the blood belongs to some species of monkey from which the tick had sucked it. Two holes in the tick’s body indicate that the specimen was injured, possibly by another monkey who was grooming its partner, and ended up trapped in amber.

This trivial event that occurred millions of years ago was preserved in an extraordinary way and today allowed to study the red blood cells and determine that they were infected by that tick. Today the only species of similar tick that infects blood cells of various mammals, including humans, is Babesia microti, also known as Theileria microti after its species was assigned to a different genus of those parasites.

This research was led by George Poinar, Jr., an entomologist super-veteran of studies of insects trapped in amber. He also wrote some essays on the subject that also mention the possibility of being able to extract the DNA of some animal preserved in amber. For this reason, he’s considered the inspiration for Michael Crichton for the idea that led to the development of “Jurassic Park”.

The possibility to perform a kind of medical examination of such an old fossil gave the researchers the opportunity to better understand the history and evolution of this type of disease. By extending the studies to quite different parasites, there are diseases against which humans are still struggling and various species belonging to the Piroplasmida order can also affect breeding animals with consequences that can be heavy.

It’s for this reason that a research of a type that’s usually interesting mainly for paleontologists was published in a magazine about the medical aspects of entomology. All information on the evolution of ticks and the diseases associated to them can contribute to medical research.

Fossil blood cells (Photo courtesy Oregon State University)
Fossil blood cells (Photo courtesy Oregon State University)

Leave a Reply

Your email address will not be published. Required fields are marked *