50 million-year-old fossil assassin bug has unusually well-preserved genitalia The fossilized insect is tiny and its genital capsule, called a pygophore, is roughly the length of a grain of rice. It is remarkable, scientists say, because the bug’s physical characteristics – from the bold banding pattern on its legs to the internal features of its genitalia – are clearly visible and well-preserved. Recovered from the Green River Formation in present-day Colorado, the fossil represents a new genus and species of predatory insects known as assassin bugs. The find is reported in the journal Papers in Palaeontology. Discovered in 2006 by breaking open a slab of rock, the fossilized bug split almost perfectly from head to abdomen. The fracture also cracked the pygophore in two. A fossil dealer later sold each half to a different collector, and the researchers tracked them down and reunited them for this study.