Featured Research

from universities, journals, and other organizations

Bones Of Baby Ice Age Sloth Carefully Reconstructed

Date:
June 26, 2006
Source:
University Of Iowa
Summary:
For the past three years, students, staff and volunteers from the University of Iowa Museum of Natural History, UI Department of Geoscience in the College of Liberal Arts and Sciences and the Office of the State Archaeologist have been excavating, analyzing and carefully reconstructing the bones of an ice-age giant sloth from a site near Shenandoah, Iowa.

Lindsay Eaves-Johnson, Graduate Assistant, Department of Anthropology.
Credit: Photo courtesy of David Brenzel

For the past three years, students, staff and volunteers from the University of Iowa Museum of Natural History, UI Department of Geoscience in the College of Liberal Arts and Sciences and the Office of the State Archaeologist have been excavating, analyzing and carefully reconstructing the bones of an ice-age giant sloth from a site near Shenandoah, Iowa. Like detectives at a 12,000-year-old crime scene, the team has been attempting to piece together a life history of this extinct, furry, SUV-sized mammal. What did it eat? Why did it die? And why did sloths mysteriously become extinct along with over three dozen other large ice age animals?

Related Articles


The mystery has suddenly gotten much more complicated. The museum has announced the research team has recovered more than 30 smaller bones which have been confirmed as belonging to a juvenile version of the same species "probably about one year old," according to Greg McDonald, the world's foremost giant sloth authority and senior curator of natural history at the National Park Service in Ft. Collins, Colo. "With 30-plus bones I would rank this the second-most complete juvenile Megalonyx ever found."

The bones were found about 10 feet away from where the first adult bones were discovered. "This is the first time an immature sloth of this species has been found associated with an adult," said David Brenzel, curator of the UI Museum of Natural History. "The bones are surprisingly well-preserved. Ribs are fragile, if we can find 20 that look this good, the condition of any other bones that are still out there must be exceptional."

The new specimen was excavated in a series of weekend trips that began in April and ended June 11. According to Brenzel, more than two dozen volunteers from all over Iowa helped in the recovery effort. "The bones were sitting smack-dab on the bottom of the creek. We didn't want to lose them in a spring flood," he said.

Even before diggers found the new sloth, the site had yielded almost 90 bones from an adult -- the second most complete adult skeleton of this species ever recovered. Bob and Sonia Athen first discovered the bones in the summer of 2001 behind their home, along the West Tarkio Creek, which forms the border between their land and land owned by Dean and Loreta Tiemann of Lincoln, Neb. The Athens began gluing the pieces together that winter. Sonia and her daughter Katie, a UI student, subsequently brought the bones to Iowa City, where Holmes Semken, emeritus professor of geoscience and leader of the sloth research project, identified them as the remains of Megalonyx Jeffersoni, or Jefferson's Ground Sloth.

Although other sites have previously produced remnants of juvenile sloths, none has ever been found directly associated with an adult. "When paired with the adult, the juvenile represents a one-of-a-kind find," Semken said.

Conclusions drawn from sloth specimens recovered from separate locales and different geologic times are highly speculative because unknown variables muddle the causes and effects, said McDonald. "This is unprecedented; two individuals living and dying in the same place at the same time form a Rosetta Stone for understanding these extinct animals," he said.

The discovery opens the door to research that has never been possible before. "Frequently all we can do is take physical measurements of the bones. What's so exciting is the potential window this opens into the maternal behavior of giant sloths," McDonald said.

The museum will have to extract and sequence the DNA to prove that the two finds constitute a "sloth family," but the close association of the fossils is compelling evidence that they are related, Brenzel said, adding that the museum also learned in May that it has been awarded an $8,114 National Science Foundation (NSF) grant for further excavation of the find. He said the discovery will drive a major rewrite by the research team of a second grant proposal to fund further analysis of the fossils.

"This adds a whole new dimension to our NSF proposal," Semken said. Tests can indicate climate, diet, and possible migration patterns of the animals, among a host of other important characteristics. Together, the two individuals may help establish parameters for age of sexual maturity, growth rates and diet changes with age.

"The window into the biology and behavior of this extinct species is unprecedented," McDonald said.

The museum is currently preparing a temporary exhibit of the new bones. In a reference to the famous T-rex dinosaur at Chicago's Field Museum, UI Museum of Natural History director Pamela Trimpe said, "This is Iowa's Sue. We're very grateful to everyone, but especially the volunteers and people of southwest Iowa who have made it possible to bring this incredible discovery to the attention of the world."

Additional information about sloth digs and research can be found on the Museum of Natural History Web site at: http://www.uiowa.edu/~nathist/Site/sloth/index.html.


Story Source:

The above story is based on materials provided by University Of Iowa. Note: Materials may be edited for content and length.


Cite This Page:

University Of Iowa. "Bones Of Baby Ice Age Sloth Carefully Reconstructed." ScienceDaily. ScienceDaily, 26 June 2006. <www.sciencedaily.com/releases/2006/06/060626123721.htm>.
University Of Iowa. (2006, June 26). Bones Of Baby Ice Age Sloth Carefully Reconstructed. ScienceDaily. Retrieved November 27, 2014 from www.sciencedaily.com/releases/2006/06/060626123721.htm
University Of Iowa. "Bones Of Baby Ice Age Sloth Carefully Reconstructed." ScienceDaily. www.sciencedaily.com/releases/2006/06/060626123721.htm (accessed November 27, 2014).

Share This


More From ScienceDaily



More Fossils & Ruins News

Thursday, November 27, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

New Dinosaur Species Found in Museum Collection

New Dinosaur Species Found in Museum Collection

Reuters - Innovations Video Online (Nov. 27, 2014) A British palaeontologist has discovered a new species of dinosaur while studying fossils in a Canadian museum. Pentaceratops aquilonius was related to Triceratops and lived at the end of the Cretaceous Period, around 75 million years ago. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Classic Hollywood Memorabilia Goes Under the Hammer

Classic Hollywood Memorabilia Goes Under the Hammer

Reuters - Entertainment Video Online (Nov. 26, 2014) The iconic piano from "Casablanca" and the Cowardly Lion suit from "The Wizard of Oz" fetch millions at auction. Sara Hemrajani reports. Video provided by Reuters
Powered by NewsLook.com
3D Map of Antarctic Sea Ice to Shed Light on Climate Change

3D Map of Antarctic Sea Ice to Shed Light on Climate Change

Reuters - Innovations Video Online (Nov. 24, 2014) A multinational group of scientists have released the first ever detailed, high-resolution 3-D maps of Antarctic sea ice. Using an underwater robot equipped with sonar, the researchers mapped the underside of a massive area of sea ice to gauge the impact of climate change. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
Ruins Thought To Be Port Actually Buried Greek City

Ruins Thought To Be Port Actually Buried Greek City

Newsy (Nov. 24, 2014) Media is calling it an "underwater Pompeii." Researchers have found ruins off the coast of Delos. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins