Friday, January 29, 2010

Pennsylvania's Tusker

On January 23rd, a new and spectacular exhibit opened at The State Museum of Pennsylvania. The star attraction is a completely articulated skeleton of an adult mastodon. A mastodon is one of two types of elephants species that roamed Pennsylvania during the Ice Age over 12,000 years ago. This individual stood nine feet tall and would have weighed 8000 to 10,000 pounds in the flesh. They inhabited an open woodland environment and browsed on twigs and leaves. The specimen was discovered in 1968 near Marshalls Creek in the Pocono’s.

The other type of woolly elephant that lived in Pennsylvania was the mammoth. These were larger than mastodons with high foreheads and longer tusks. Mammoths grazed on grass and lived in an open environment with bison and horses. That both elephant types were contemporaneous, demonstrates the diverse nature of the forests and grasslands that covered Pennsylvania during the Ice Age.

The mastodon skeleton is part of a larger exhibit called Tusks! Ice Age Mammoths and Mastodons. Created by the Florida Museum of Natural History, this exhibit features more than 80 specimens that include rare Ice Age animals such as saber toothed cats, horses, bison, short faced bears, giant ground sloths and giant armadillos. These were all recovered from rivers in Florida and are very well preserved. Due to their large size, these animals are called megafauna. They were the most common type of animal all over the world during this time and their large size was an evolutionary response to the cooler temperatures of the Ice Age. Megafauna were the dominate animals for about two million years when, for reasons not totally understood, they became extinct about 11,000 years ago.

The Marshalls Creek mastodon was excavated by paleontologists who study life in the past based on fossils. Many of the remains in the Tusks! exhibit were excavated by archaeologists who study past human behavior based on artifacts. Archaeologists are very interested in these animals because they tell us about the environment of the past and, in fact, some of these animals were hunted by the first humans in the New World.

The Tusks! exhibit includes stone tools that may have been used to kill or butcher these animals. Archaeologists are interested in understanding the relationship between extinct Ice Age animals, especially mammoths and mastodons and the earliest humans in the New World. Of special interest to archaeologists is the question - Why did the Ice Age megafauna become extinct between 11,000 and 15,000 years ago and did humans have a role in their extinction?

Since the 1970s, the so called “Clovis First” theory has proposed that humans migrated into North America about 12,000 years ago via the Bering Strait Land Bridge. They entered a land where the animals had no experience with the killing power of spear throwing Paleolithic humans. These early migrants to the New World focused on big game hunting and as they moved south, they exterminated the animals in one region and moved onto the next. There are approximately sixteen sites west of the Mississippi River that contain the remains of mammoths (n=62) and mastodons (n=2) killed by these early hunters. East of the Mississippi there are five sites containing five mastodons possibly killed by humans. All of this is known as the “over-kill hypothesis” and blames human hunting for the mass extinction of these animals at the end of the last Ice Age.

Challenging the “Clovis First theory”, is the “Pre-Clovis or early entry theory” that proposes that humans migrated into the New World between 18,000 and 20,000 years ago and slowly spread throughout North and South America. They were opportunistic foragers who hunted animals, fished and gathered plant foods. There were so few of these people that they are practically invisible in the archaeological record and very few sites have been found from this time period (prior to 12,000 years ago). Gradually, these Pre-Clovis populations increased and by 11,100 years ago, they invented a very distinctive spear point style called a fluted point and their artifacts became more common at archaeological sites. Pre-Clovis people probably also hunted elephants, there are a few examples in South America but they did not cause their extinction. In response to the “overkill hypothesis” the proponents of the Pre-Clovis theory remind us that humans had been hunting megafauna in the Old World for tens of thousands of years and they did not cause their extinction in those regions. They argue that environmental change was the reason for their demise.

There have been numerous discoveries of mammoth and mastodon in Pennsylvania but so far, none show butchering marks by humans and none have been found with stone tools. However, the Marshalls Creek specimen is very interesting. While over 90% of the skeleton was recovered, the tusks are mysteriously missing. The carbon 14 dates for this specimen are 12,000 years old and Pre-Clovis in age. Ivory was a extremely valuable resource. Could the tusks have been removed by early hunters? Or were they instead scavenged by Clovis peoples sometime after the mastodon’s natural death? Archaeologists continue to research these questions and others in attempts to better understand early human cultures.

Please come view the exhibit yourself and read about these fascinating finds. There is much more to learn about our past and the newly restored Marshalls Creek mastodon is now preserved for all to appreciate. The Tusks! exhibit will be on display until May and at that time the Marshalls Creek Mastodon will be moved to the State Museum’s Hall of Geology on the third floor for permanent display sometime in the fall.

For more information, visit or the Hall of Anthropology and Archaeology at The State Museum of Pennsylvania .

1 comment:

  1. Until April 4th, you can see similar fossils at the New Jersey State Museum in an exhibit called Rising Tide: Climate Change and New Jersey. A significant portion of this exhibition includes Ice Age animal fossils.