New Species of Big-headed Flies Discovered in Eocene Epoch Fossil Beds

A modern big-headed fly, with a round head covered by compound eyes. Photo by Nikola Rahmé.

Scientists recently discovered three new, extinct fossil species of big-headed flies. The fossils show their early evolution parallels an ecological revolution, one that formed the character of our modern natural communities.

“The newly discovered species were preserved in Eocene epoch fossil beds that are 49 million to 52 million years old, which is about 12 million to 15 million years after the extinction of the dinosaurs,” said Simon Fraser University’s Bruce Archibald. “This great extinction event also disrupted forests in which the dinosaurs had lived, with mostly low diversity and greatly disrupted food webs for millions of years.”

By the time of these flies in the Eocene, however, forests had diversified again, but this time with many new kinds of flowering plants that are familiar to us today, such as birches, maples, and many others.

Along with these new, rich forests came an expanding diversity of pollinators and herbivorous insects, and with them, diversification of their insect predators, including these big-headed flies.

The three new species of fossil big-headed flies are members of the living family Pipunculidae. One fossil, Metanephrocerus belgardeae, is well-enough preserved to name as a new species. It is named in honor of its finder, Azure Rain Belgarde, a student at the Paschal Sherman Indian School, who uncovered it on a field trip to the fossil deposits at Republic, Washington state.

The other two unnamed, more enigmatic species are described from less complete fossils uncovered at Quilchena in southern British Columbia.

“Big-headed flies are a group of bizarre insects whose round heads are almost entirely covered by their bulging compound eyes, which they use to hunt for mainly leafhoppers and planthoppers, renowned common garden insect pests,” said Archibald. “With these new discoveries, we see that the early history of these oddly shaped insect predators provides a part of the puzzle revealing the broad ecological-evolutionary revolution of expanding predator-prey relationships and increasing biodiversity during the formation of new ecosystems.”

Read more at:

Early Eocene big headed flies (Diptera: Pipunculidae) from the Okanagan Highlands, western North America

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: