Strategic Communications and Marketing News Bureau

Ancient extinct sloth tooth in Belize tells story of creature’s last year

Anthropology Ph.D. student and study lead author Jean Larmon analyzed the sloth tooth for clues about its diet and the climate.

Anthropology Ph.D. student and study lead author Jean Larmon analyzed the sloth tooth for clues about its diet and the climate.

CHAMPAIGN, Ill. — Some 27,000 years ago in central Belize, a giant sloth was thirsty. The region was arid, not like today’s steamy jungle. The Last Glacial Maximum had locked up much of Earth’s moisture in polar ice caps and glaciers. Water tables in the area were low.

The sloth, a beast that stood up to 4 meters tall, eventually found water – in a deep sinkhole with steep walls down to the water. That is where it took its final drink. In 2014, divers found some of the sloth’s remains – parts of a tooth, humerus and femur – while searching for ancient Maya artifacts in the pool, in Cara Blanca, Belize.

Though partially fossilized, the tooth still held enough unaltered tissue for stable carbon and oxygen isotope analysis, which provided clues to what the sloth ate in the last year of its life. This, in turn, revealed much about the local climate and environment of the region at the time. The findings, reported in the journal Science Advances, will aid the study of similar fossils in the future, the researchers said.

“We began our study with the hopes of gaining a better understanding of the landscape within which large mammals went extinct and humans emerged in central Belize,” said University of Illinois graduate student Jean T. Larmon, who led the research with U. of I. anthropology professors Lisa Lucero and Stanley Ambrose. “In the process, we discovered which part of the tooth had best maintained its integrity for analysis. And we refined methods for studying similar specimens in the future.”

U. of I. anthropology professor Lisa Lucero and her colleagues discovered the remains of an extinct giant sloth in central Belize.

While searching for ancient Maya artifacts in a sinkhole in central Belize, U. of I. anthropology professor Lisa Lucero and her colleagues discovered the remains of an extinct giant sloth. An analysis of the sloth tooth offers insight into the climate and environment of the region 27,000 years ago.

The new findings “add to the evidence that many factors, in addition to a changing climate, contributed to the extinction of megafauna in the Americas,” said Lucero, who studies the ancient Maya of central Belize. “One of those potential factors is the arrival of humans on the scene 12,000 to 13,000 years ago.”

The teeth of giant sloths like the one found in Belize, Eremotherium laurillardi, differ from those of other large mammals, like mammoths, that went extinct between 14,000 and 10,000 years ago, Larmon said.

“Giant sloth teeth have no enamel, the hard, outer layer of human and some animal teeth that can be analyzed to learn about their diet,” she said.

Pool 1, where the ancient sloth tooth was discovered. The structure at the bottom of the photo is an ancient Maya ceremonial platform

Pool 1, where the ancient sloth tooth was discovered. The structure at the bottom of the photo is an ancient Maya ceremonial platform

Other factors have limited scientists’ ability to study the teeth of ancient sloths. Most are fossilized, with minerals replacing much or all of the original tissue and bone.

By using cathodoluminescence microscopy, a technique that causes minerals to glow and can detect the extent of mineralization in fossils, the researchers discovered that one type of tooth tissue, the dense orthodentin, was largely intact.

Study co-author Greg McDonald extracted a sloth tooth from this fossil bed in a large sinkhole in central Belize.

Photo by Tony Rath

Delete

Edit embedded media in the Files Tab and re-insert as needed.

Larmon drilled 20 samples of orthodentin for isotopic analysis along the 10-centimeter-long tooth fragment, spanning more than a year of tooth growth.

“This allowed us to trace monthly and seasonal changes in the sloth’s diet and climate for the first time, and also to select the best part of the tooth for reliable radiocarbon dating,” Ambrose said.

The isotopic analysis revealed that the giant sloth lived through a long dry season, which lasted about seven months, sandwiched between two short rainy seasons. The analysis also revealed that the creature lived in a savanna, rather than a forest, and consumed a variety of plants that differed between wet and dry seasons.

Divers found the sloth tooth in one of several large pools in the Cara Blanca region of central Belize.

Divers found the sloth tooth in one of several large pools in the Cara Blanca region of central Belize.

“We were able to see that this huge, social creature was able to adapt rather readily to the dry climate, shifting its subsistence to relying upon what was more available or palatable,” Larmon said.

“This supports the idea that the sloths had a diverse diet,” Lucero said. “That helps explain why they were so widespread and why they lasted so long. It’s likely because they were highly adaptable.”

The National Science Foundation and the University of Illinois supported this research

Editor’s notes:

To reach Jean Larmon, email larmon2@illinois.edu.

To reach Lisa Lucero, email ljlucero@illinois.edu.  

To reach Stanley Ambrose, email ambrose@illinois.edu.

The paper “A year in the life of a giant ground sloth during the Last Glacial Maximum in Belize” is available online and from the U. of I. News Bureau.

DOI: 10.1126/sciadv.aau1200

Read Next

Announcements Marcelo Garcia, professor of civil and environmental engineering at The Grainger College of Engineering.

Illinois faculty member elected to National Academy of Engineering

Champaign, Ill. — Marcelo Garcia, a professor of civil and environmental engineering in The Grainger College of Engineering, has been elected to the National Academy of Engineering.

Social sciences Male and female student embracing on the quad with flowering redbud tree and the ACES library in the background. Photo by Michelle Hassel

Dating is not broken, but the trajectories of relationships have changed

CHAMPAIGN, Ill. — According to some popular culture writers and online posts by discouraged singles lamenting their inability to find romantic partners, dating is “broken,” fractured by the social isolation created by technology, pandemic lockdowns and potential partners’ unrealistic expectations. Yet two studies of college students conducted a decade apart found that their ideas about […]

Engineering Civil and Environmental Engineering Professor Nishant Garg, center, is joined by fellow researchers, from left: Yujia Min, Hossein Kabir, Nishant Garg, center, Chirayu Kothari and M. Farjad Iqbal, front right. In front are examples of clay samples dissolved at different concentrations in a NaOH solution. The team invented a new test that can predict the performance of cementitious materials in mere 5 minutes. This is in contrast to the standard ASTM tests, which take up to 28 days. This new advance enables real-time quality control at production plants of emerging, sustainable materials. Photo taken at the University of Illinois Urbana-Champaign on Monday, Feb. 3, 2025. (Photo by Fred Zwicky / University of Illinois Urbana-Champaign)

Researchers develop a five-minute quality test for sustainable cement industry materials

A new test developed at the University of Illinois Urbana-Champaign can predict the performance of a new type of cementitious construction material in five minutes — a significant improvement over the current industry standard method, which takes seven or more days to complete. This development is poised to advance the use of next-generation resources called supplementary cementitious materials — or SCMs — by speeding up the quality-check process before leaving the production floor.

Strategic Communications and Marketing News Bureau

507 E. Green St
MC-426
Champaign, IL 61820

Email: stratcom@illinois.edu

Phone (217) 333-5010