MASTODON SKULL FROM OVER 13 THOUSAND YEARS DISCOVERED IN IOWA RIVERBANK

Mastodons formerly trampled over North America. These extinct animals roamed the earth for millions of years, sharing the same family tree as mammoths and contemporary elephants, until going extinct about 10,500 years ago at the end of the Pleistocene era. The retreat of the Ice Age glaciers and the expansion of human populations across the continent occurred at the same time as their decline.

Finding a fossil from this era offers a fascinating opportunity to gain additional insight into a period of change. A fascinating new find from an Iowa riverbed is a mastodon skull that provides insight into this prehistoric period.

The mastodon, scientifically known as Mammut americanum, was exterminated after a resident of rural Wayne County, Iowa, shared a picture of himself clutching a big bone that had been found—a mastodon femur. The University of Iowa archaeologists followed this lead to the sodden banks of a creek. They found a tusk in the bank that appeared to be affixed to a skull. Additional excavation validated this hypothesis.

The researchers have some fascinating possibilities because of the 2-foot tusk that protruded from the enormous skull. In fact, the structure of the tusks can tell us a lot about the animal. The state archaeologist of Iowa, John Doershuk, told Iowa Public Radio that "apparently there are techniques now to determine how many calves a female mastodon had that get recorded as a chemical signature because of the changes in the body chemistry during the pregnancy and the birth." "And the tusks keep track of that."

Early human occupants of the area used stone tools that were found during excavations near the creek. The tools are a few thousand years older than the mastodon skull, which is 13,600 years old. Still, the earliest humans were moving into Iowa at the same time the mastodon was having fun. Archaeologist Doershuk stated in a statement, "We're really hoping to find evidence of human interaction with this creature—perhaps the projectile points and knives that were used to kill the animal and do the initial butchering."

"The bones themselves may also contain evidence in the form of distinguishable cut marks."