Penis
Domestic cats have barbed penises, with about 120–150 one millimeter long backwards-pointing spines. Upon withdrawal of the penis, the spines rake the walls of the female's vagina, which is a trigger for ovulation. Lions also have barbed penises. Male felids urinate backwards by curving the tip of the glans penis backward. When male cheetahs urine-mark their territories, they stand one meter away from a tree or rock surface with the tail raised, pointing the penis either horizontally backward or 60° upward.
Edmontosaurus
The brain of "Edmontosaurus" has been described in several papers and abstracts through the use of endocasts of the cavity where the brain had been. "E. annectens" and "E. regalis", as well as specimens not identified to species, have been studied in this way. The brain was not particularly large for an animal the size of "Edmontosaurus". The space holding it was only about a quarter of the length of the skull, and various endocasts have been measured as displacing to , which does not take into account that the brain may have occupied as little as 50% of the space of the endocast, the rest of the space being taken up by the dura mater surrounding the brain. For example, the brain of the specimen with the 374 millilitre endocast is estimated to have had a volume of . The brain was an elongate structure, and as with other non-mammals, there would have been no neocortex. Like "Stegosaurus", the neural canal was expanded in the hips, but not to the same degree: the endosacral space of "Stegosaurus" had 20 times the volume of its endocranial cast, whereas the endosacral space of "Edmontosaurus" was only 2.59 times larger in volume.