Scientists working with fossilized remains generally needed an entire limb or cranium to puzzle out the sex of a prehistoric mammals they examined. The shape or size of the fossil were the bases for determining gender.
As DNA testing advanced, researchers were able to determine sex from fossil fragments, even though usable DNA is not always available in twenty-thousand-year-old remnants. Better DNA testing, though, is confirming what visitors to natural-history museum have noticed: most fossilized specimens are male. Apparently it was a man’s world in prehistoric times.
Were there many more male than female mammals in the ancient world? Not likely. Scientists have concluded that the preponderance of male fossilized remains is probably the result of reckless male behavior. Male mammoths, for example, especially young ones, were much more inclined to travel alone, away from the wisdom and protection of the herd, and more likely to get into some kind of fatal trouble. On their own, chances of getting stuck in a pit or encountering human hunters greatly increased. Meeting their demise in bogs or crevices or lakes is good for scientists as those death sites are good at preserving their remains.
Some things don’t change. As one paleontologist said, young males “were more likely to do silly things, like die in tar pits.”