Ancient sloth bone found in California mountains
During the last ice age, known as the Pleistocene, Santa Cruz County was a wild place populated with ancient humans and largerthan-life creatures, or megafauna, such as mastodons and mammoths. But not until a group of adventurous kids brought in a mysterious fossil to the Santa Cruz Museum of Natural History did anyone in the scientific community know that massive ground sloths once roamed the region.
“Our paleontology adviser Wayne Thompson was immediately so excited by this specimen, and when he gets excited about something, you know that it’s going to be good,” said Executive Director of the Santa Cruz Museum of Natural
History Felicia Van Stolk.
According to Van Stolk, a group of kindergarteners and first-graders from Tara Redwood School were playing outside one fateful day on a field trip in the Santa Cruz Mountains when they stumbled upon the fossilized bone.
“One of the students pulled up this great big stick, except that it wasn’t a stick,” said Van Stolk. “The kids then brought it to their classroom and were cleaning it off with paint brushes, pretending to be paleontologists.”
The bone remained in the classroom for a short time before the family of one of the young citizen scientists thought to bring it into the Museum of Natural History to get to the bottom of the strange fossil’s identity.
“We tapped into our resources and connections and had it confirmed to be this very rare specimen,” said Van Stolk. “We were just over the moon.”
At the museum Friday, Thompson, principal paleontologist at Pacific Paleontology, told the Sentinel that the bone has been identified as the left radius bone of a Jefferson’s ground sloth, named after the Founding Father Thomas Jefferson, and is the first of its kind ever to be found in the county. However, the exact age of the specimen is still being determined.
Thompson explained that Jefferson’s ground sloths lived between about 300,000 years ago to about 11,700 years ago and remnants of their existence are rarely found in California.
Jefferson’s ground sloths lived near creeks and rivers and under canopy forests and were about as big as an ox and generally weighed more than a ton.
“They would be about 6 feet tall on all fours and they’d be a good 8 to 9 feet tall when they stood up,” said Thompson.
Thompson mentioned that he was stoked about the specimen not only because of its rarity and the fact that it was the first of its kind in the county, but also because it was discovered by a group of young kids.
For those who are inspired by the find and want to venture out on a fossilfinding mission of their own, Thompson has some advice.
“The golden rule there is to know before you go,” said Thompson. “Do some background research and know the regulations of where you’re going. If you are on public land, it is illegal to take this kind of artifact unless it is in immediate danger of being destroyed. Document with photographs and try to pin where it is and report any finds to a museum. Most of all, be excited. There is so much more that is out there yet to be discovered.”