Top: The daddy longlegs with penis identified. Below: Close-up of the fully erect penis.

Top: The daddy longlegs with penis identified. Below: Close-up of the fully erect penis.
Image: J. A. Dunlop et al., 2016

Daddy longlegs, in addition to their extended appendages, are endowed in other ways as well, as this chunk of Cretaceous amber revealed back in 2016. Here’s how I described the discovery at the time:

When it died, this ancient creature was clearly in a state of arousal, and possibly in the vicinity of a female. How it went from a potential union to paleontological posterity is anyone’s guess. Perhaps it fell into oozing resin amid all the sexual excitement. Alternately, the male daddy longlegs may have accidentally fallen into some tree resin as it was going about its daily business, and as it was struggling, its blood pressure rose, forcing its penis to squeeze out accidentally.

This insect’s penis was so unique in terms of its shape, scientists had to create an entirely new family of arachnids, and a new species, Halitherses grimaldii. As the researchers wrote: “This is the first record of a male copulatory organ of this nature preserved in amber and is of special importance due to the age of the deposit,” which dates back some 99 million years.