A Surprise in a 50 Million-Year-Old Assassin Bug Fossil: Its Genitals - The New York Times

The exquisite preservation of the fossil, which represents an undescribed species, is “extraordinary,” said Daniel Swanson, an entomologist at the University of Illinois at Urbana-Champaign and the paper’s lead author.

Much less is known about the lifestyle of assassin bugs of yore, of which only 50 or so species have been unearthed in fossil form.

The fossil was first pried from a wreath of rock in Colorado’s Green River Formation, a treasure trove of fossil fish and insects.

The extraction process split the fossil into two mirror images, each stretching the length of the bug’s body, that ended up in the hands of different fossil collectors.

Dan Judd, the owner of the piece’s partner fossil, soon followed suit, earning the insect its species name.

Swanson said, not unlike the exoskeletal structures that swaddle the rest of the bug’s body.

Genitalia isn’t always the go-to structure for differentiating insect species.

The researchers can’t be sure what females of this species looked like.

Despite some subtle differences, the team’s new assassin bug doesn’t look all that different from many of its contemporary kin — a hint that this group of insects hit upon evolutionary success early, and stuck with it