JOHNSON CITY (January 24, 2013) – A recent article in the prestigious journal PLOS ONE reveals new information about the early dietary behavior of saber-toothed cats and American lions.
The article was published by a team of scientists that includes Dr. Larisa R.G. DeSantis from Vanderbilt University; Drs. Peter Ungar and Jessica Scott from the University of Arkansas; and Dr. Blaine Schubert from East Tennessee State University, who is director of the Don Sundquist Center of Excellence in Paleontology and the ETSU and General Shale Brick Natural History Museum, as well as an associate professor in the Department of Geosciences.
“In summary, our research focuses on understanding how saber-toothed cats and American lions ate their meals while living around the tar pits of southern California,” Schubert said.
According to Schubert, the tar pits, otherwise known as Rancho La Brea (or La Brea), are considered to be one of the most significant fossil sites in the world, dating back to the late part of the Ice Age.
“The site is known to have been a ‘natural trap’ where animals became stuck in tar,” he said. “Carnivores were particularly attracted by other dead or dying animals, and therefore a cyclical pattern of carnivore entrapment occurred, resulting in extremely high numbers of some meat-eating species.”
The new study features a technique called dental microwear texture analysis (DMTA), which uses a confocal microscope to produce a three-dimensional image of wear surfaces on teeth that is then analyzed for microscopic wear patterns using automated software.
Studies on living cheetahs, lions and hyenas have demonstrated that wear patterns reflect a degree of bone consumption or bone avoidance. The saber-toothed cat’s wear most closely resembles those of the present-day African lion, which incorporates some bone-crushing when eating. In contrast, the American lion wear was more similar to cheetahs, which typically avoid bone.
“Our research results were unexpected and have important behavioral implications for these giant cats,” Schubert said.
Previous work by other researchers on these and other carnivores from La Brea report exceedingly high numbers of broken teeth in the front of the mouth – three times higher than their living counterparts. These results were interpreted to represent higher levels of carcass consumption and possibly more competition for food than living large carnivores.
“Thus, the overall theme often applied to La Brea is ‘times were tough,’” Schubert said.
“Combining our research results with those of other researchers sheds new light on this interpretation at La Brea,” he added. “The dental microwear results indicate that the level of carcass consumption was actually low and therefore competition may have been as well. We hypothesize that the high level of broken teeth, primarily in the front of the mouth, may have resulted from hunting a wide variety of Ice Age megafauna.
“Times were certainly tough at La Brea, but not necessarily because food resources were low,” Schubert noted.