The Manis Mastodon

Did humans kill a mastodon and a bison 14,000 years ago?

Last week I had the pleasure of visiting one of the more famous fossil sites in Washington, the Manis Mastodon in Sequim. Little remains except for a concrete block with a plaque, which notes that it is on the national register of historic places, but it’s still a pretty nifty story and pilgrimage location for a geogeek like me.

In August 1977, Emanuel Manis was excavating peaty muck from a pond on his property when he unearthed two tusks, the larger of which was more than six feet long. Convinced by his wife Claire that the tusks were important, the couple reached out to experts and connected with WSU archaeologist Carl Gustafson. Over the next two years, he and a team of researchers excavated a single, large, and old (based on tooth wear and diseased bone, he may have been 45 years old) male mastodon, along with parts of a bison and a muskrat.

What made the find startling was the discovery of a bone projectile point embedded in one of the mastodon’s ribs. Gustafson concluded that the great animal had died about 12,000 years ago, soon after he had been attacked by people. Subsequent analysis has pushed the date back even earlier to 13,800 years ago before present. This is staggering as it implies that people moved into this region shortly after the retreat of glacial ice, and that they began harvesting the region’s charismatic megafauna. But it is not the lone evidence for humans and hunting from this time period.

Mastodon rib with the embedded bone projectile point. (A) Closeup view. (B) Reconstruction showing the bone point with the broken tip. The thin layer represents the exterior of the rib. (C) CT x-ray showing the long shaft of the point from the exterior to the interior of the rib. (D) The entire rib fragment with the embedded bone projectile point. From Science 11/21/2011.

More than two decades after Emanuel Manis found his tusks, workers on Orcas Island excavating a wetland to create a pond (Ayer Pond) discovered 98 bones of the extinct bison, Bison antiquus (a considerably larger species than the modern one with exceptionally long horns). This animal, which was radiometrically dated to 13,835 years before present, appears to have been butchered. Researchers based their conclusion on marks on the bones produced by a blade used to cut the meat, the character and location of impact marks on the bones, and the bone fracture pattern, as well as the absence of any gnawing or other signs indicating animal predation or scavenging.  

Recovered elements and fragments with modifications: (a) skeletal diagram; modifications only found in black areas (red in color) and unshaded bones absent; (b) two deep V-section chop/cutmarks to right distal tibia, one split astragalus; (c) refit green bone fractures of right radio-ulna and distal humerus; (d) concentric fractures (ring fractures) partially encircling points of impact. From Quaternary International 233 (2011)

Not all researchers agree with the conclusions about the connection between early human hunters and the Ayer Pond bison and Manis mastodon. Some paleontologists observe that the location of the point in the Manis mastodon, the lack of any indication that the point was shaped, and the possibility that the backhoe used in the excavation could have mashed the point into the animal raise doubts that people killed the animal. Scientists further contend that the very old Manis mastodon probably died as a result of a fight with another male; the “point” was likely from his own body. The absence of any human made tools at Manis, as well as Ayer Pond, also puts into question the conclusion of butchering or killing.

Although we may not have unequivocal evidence of humans killing massive Pleistocene beasts, people and mastodons, as well as giant sloths, mammoths, horses, and deer were here at the same time. One can easily imagine that such large animals could have provided a key food source—whether scavenged or killed—for the first residents of what would become Washington. It must have been both an exciting and potentially terrifying world to inhabit.

(This newsletter is based on work for a book about Washington fossils that I am co-authoring with Dr. Liz Nesbitt.)


Please excuse the title from my previous newsletter. As I hope you realized, it was a temporary holding name that I forget to change. It should have been “Terror of the Docks.”

Exciting news. The UW Press is planning on a second printing of Homewaters, which means the first is almost sold out “much earlier than expected,” as my editor at the Press told me. If you want to be a total hipster, and I suspect many of you do, of course you will want a copy of the first printing. I still have a few available. Only $34, which includes taxes, S&H, and my autograph.