Castroville Mammoth
About the COLUMBIAN MAMMOTH
Columbian mammoths (Mammuthus columbi) are effectively North American mammoths. The Columbian mammoth is thought to have evolved from an earlier Old World species, Mammuthus trogontherii (the steppe mammoth). In Eurasia, the steppe mammoth evolved into Mammuthus primigenius (the woolly mammoth), which later migrated to North America. The range of woolly mammoth and the range of the Columbian mammoth overlapped in some areas of North America; but the Columbian mammoth extended as far south as Mexico and Nicaragua, while the woolly mammoth remained in the more northern latitudes. For the most part, both of these species appear to have gone extinct some time around 12,500 – 9,000 years ago. However, researchers have become aware of several small remnant populations on Wrangell Island in the Bering Strait and also on the Santa Barbara Channel Islands; these populations appear to have continued for several thousand more years before they too became extinct.
Large male specimens of Columbian mammoth stood 14 feet tall and weighed as much as 10 (metric) tons – on average, making them larger than the woolly mammoth. The Columbian mammoth was likely a grazer and limited browser – they ate grasses and sometimes low foliage. Estimates (based upon rates of modern elephants) are that an adult Columbian mammoth ate around 300 pounds of vegetation daily.
The Columbian mammoth differs from the woolly mammoth in location, size, skull shape, teeth shape, and tusk shape (Columbian mammoth tusks spiral inward, whereas the woolly mammoth curls upward). Columbian mammoths lack the large “knob” at the top of the head that we find on the woolly mammoth; and neither have the same teeth, tusks, and frame as the American mastodon (Mammut americanum) – a completely different genus of ancient elephant. The Columbian mammoth likely lacked the full wooly undercoat of the woolly mammoth, but did have a long stringy outer coat, similar to the woolly mammoth. Our hair samples may reflect this.
THE EXCAVATION SITE AND THE SPECIMENS
The mammoth site was found in 2011 by artichoke farmers in Castroville (unincorporated Monterey County) – as they were leveling-out the soil with heavy equipment, they struck a mammoth tusk. This brought their attention to the find, which was reported to Mark Hylkema, a California State Archaeologist. Hylkema has significant field experience in the Monterey Bay region and prepared an initial findings report that was forwarded to a number of professional paleontologists and other colleagues. In doing so, a research team was gathered, including faculty members and students of the Foothill College Anthropology Department. Given the limited window of time allocated for excavation, they proceeded to expose and document the remains.
To date, only 10% of the total skeletal remains have been uncovered; assuming that all of the skeletal elements of the individual are at the site. Ground-penetrating radar was used to direct excavations, informing us about the location of the yet-to-be excavated remains.
Though this is certainly not the first example of a Columbian mammoth found in California, it is the first one found in Monterey County. Other specimens have been found in San Jose (2005) and Fremont (1960s).
We have found hair from the mammoth – the distinctive, thick hairs are visible in the clay context of these remains. When the pigment is intact, the hair is reddish-brown. This is similar to the hair color of woolly mammoths, but the hair of Columbian mammoths is typically less coarse.
Hair from woolly mammoths is often recovered in locations where the remains were buried in permafrost, as this preserves soft tissues. Columbian mammoths live in warmer, more southern regions than their woolly cousins, so hair is often not found. There are only a few other reported instances where Columbian mammoth hair has been found.
Identified and likely present elements of the mammoth.
Stephan Schuster, a member of our investigative team, is a paleofaunal DNA specialist at Pennsylvania State University. Our hopes are that he will be able to extract ancient DNA from the hair follicles, or from the tusk ivory. If he succeeds, this will be the first published recovery of DNA from this species. This DNA information could be used to understand exactly how the Columbian mammoth is related to woolly mammoth and modern elephant species, and to better understand the common ancestor of woolly mammoths, modern elephants, and Columbian mammoths.