Megafauna were pretty big to be "our animal friends" but here's some interesting stuff about them:
As recently as 10,000 years ago, North America was filled with massive megafauna who influenced plants and the landscape in important ways that we can still perceive today. In Ohio the ancient megafauna included mastodon, mammoth, ground sloth, peccary, giant beaver, horse, bison, muskox, stagmoose, short-faced bear, and very likely dire wolf and saber-toothed cat as well. The American Mastodon (Mammut americanum) in particular was a keystone 'ecosystem engineer' who maintained open woodlands and prairies during the 5 million years in which they roamed the planet.
These Mastodons were browsers and can almost be thought of as oversized Whitetail Deer, capable of overturning large trees and creating a browse line many meters above the ground. Unlike Mammoths, Elk or Bison who specialize in eating grasses, these browsers such as Mastodons would use their long trunks to strip trees of their leaves and fruit. Along with other megafauna like Giant Sloth, Mastodons forced many native North American plants to adapt to extreme, harsh browsing. Nearly all native Sumac (Rhus sp.) sucker, or grow new shoots off their roots, and this can clearly be attributed to the influence of ancient megafauna. Other plants of eastern North America that share the characteristic of suckering includes Wild Plum (Prunus sp.), Pawpaw (Asimina triloba), Persimmon (Diospyros virginiana), and various species of Dogwood (formerly Cornus).
The false thorns on Wild Plums and the large, intimidating thorns of the Honey Locust (Gleditsia triacanthos) are evolutionary adaptations to the days when ancient megafauna posed a serious threat to these plants survival. Although they are now extinct, it is clear that the mammoths, mastodons, ground sloths and other ancient creatures still influence native plant communities to this today
Pawpaw fruit, a huge tropical-looking fruit that may seem out of place in the midwest. In fact, Ohio is the heartland of Pawpaw's range. Giants like Mastodons and Ground Sloths formerly dispersed their large seeds.
Pawpaw thicket below:
The ferocious thorns of Honey Locust, designed to persuade Giant Sloths and other large creatures from climbing the tree in order to eat the sweet seedpods. A fine argument against climbing, to this day.
One single American Persimmon tree was cut down at a park in Kentucky. The ensuing thicket grew from the roots of that single cut Persimmon. You can clearly see how this would be beneficial adaptation for a tree if a large creature (such as a ground sloth or mastodon) ever mangled or destroyed you.
Staghorn Sumac (Rhus typhina), displaying its excellent fall color. Like many shrubs of open environments, Sumac was influenced by ancient megafauna.
Wild plum thicket
Wild Plums ripening during late summer. These were the fruits that Mastodons sought out. One Mastodon fossilized dung specimen discovered in Florida was found to contain plum seeds. |
