These range in size from tiny to "heroic" in size, with the aforementioned "Oosic" coming from an Walrus, and being rather large.
There is now some question as to why humans do not have this bone, even though some of our closer relatives, like the Chimpanzee, do:
The baculum, also called the os penis or penis bone, is a puzzling thing. It sits in the tip of the organ, not connected to any larger skeletal structure. Your pet cat has one if it is a he, as does your male dog. Many male mammals do — chimpanzees, gorillas, weasels and bears. The walrus has a particularly impressive baculum, up to 22 inches in length. The bone was even larger in the past. A fossilized, 4.5-foot os penis of an extinct walrus species fetched $8,000 at auction in 2007.Less than 2 minutes for humans? Seriously?
But humans, curiously, do not have penis bones. One reading of Genesis offered an explanation for the disappearing bone by way of creation myth. It was the penis bone, not a rib bone, a pair of biblical scholars argued in 2015, that God removed to fashion Eve from Adam. (This interpretation went over about as well as one might expect.)
As to why humans lack the bones, a study published on Wednesday in the Proceedings of the Royal Society B offered a possible explanation. By the standards of primate reproduction, humans do not need to do the deed for a long enough time to warrant an os penis. Plus, our breeding habits are, in the context of our great ape cousins, fairly low-pressure.
A pair of researchers at the University College London examined several sexual characteristics of primates and mammal carnivores, including features like polygamy, testes mass, seasonal mating and intromission time (how long an act of penetration lasts). For primates, the best predictor for whether the male had a penis bone was if intromission lasted three minutes or longer. There was also a correlation between long intromission and length of the bone for both primates and carnivores.
Study author Matilda Brindle wrote at the Conversation that “humans don’t quite make it into the ‘prolonged intromission’ category. The average duration from penetration to ejaculation for human males is less than two minutes.” These long bouts of primate intromission are not exactly romantic. The end goal is gestation, not gesture. They are insurance to a male mammal, Brindle pointed out, that a female does not mate “with anyone else before his sperm have had a chance to work their magic.”
Damn! I barely have her shoes untied in 2 minutes.*
As an aside, if you Google Oosic, the almost all first links are for knife handles made from Walrus baculi.
*It's not that I don't know how to untie shoes, it's that I am not using my hands.