Oct. 19, 2006 —Battle scars on male mastodon tusks reveal that the Ice Age giants fought in brutal combat each year during seasonal phases of heightened sexual activity and aggression, according to new findings that will be announced at this week's Society of Vertebrate Paleontology meeting in Ontario.
The discovery counters the view that now-extinct mastodons were peaceful, passive creatures that rarely engaged in battles.
It also strengthens the link between mastodon and modern elephant behavior, since male bull elephants also fight seasonal, hormonally-charged battles to show their dominance and win desired mates.
Like warriors with different weapons, however, the two animals had distinct fighting techniques, lead author Daniel Fisher, a University of Michigan paleontologist, told Discovery News.
"Mastodon tusks curve upward strongly at the tips and appear to have been used in a vigorous up-thrusting motion," explained Fisher, who added that elephant tusks are less curved and therefore tend to be used more "in a straight thrusting move."
Fisher's analysis of mastodon tusks and skulls revealed that such ramming caused the lower part of the tusk to rotate backward, "crunching it against the back wall of the tusk socket."
He found that although the tusk continued to grow by adding layers of ivory to its base, pitted scars line up along the outside curve of the tusk base.
"It's not just one event, but a whole series of events that is preserved in this tusk record of fighting," he said.
Using previous research about mastodon tusk growth patterns, Fisher also found the scars correspond to seasonal patterns — the pits formed each year of the adult male animal's life during mid-spring to early summer.
Studies on mastodon vertebrae also helped fill out a picture of gory battles between the 8 to 10-foot-tall creatures.
