EMBARGO: July 1, 2015 11 AM Pacific / 2 PM Eastern
Dagger-like saber-toothed cat canines took
years to grow
New technique suggests rapid canine growth, but
delayed dental maturity in saber-toothed cats
The fearsome saber-toothed cat teeth may have
fully emerged later in life than those of modern big
cats, but they grew at a rate about double that of
their living relatives, according to a study
published July 1, 2015 in the open-access journal
PLOS ONE by Aleksander Wysocki from
Clemson University, and colleagues.
The saber-toothed cat lived in North and South
America until going extinct about 10,000 years
ago. The cats are famous for their protruding
canines, which could grow to be about 7 inches
long. Although well-preserved fossils are available
to researchers, very little is known about the ages
at which the animals reached key developmental
stages.
Using saber-toothed cat specimens recovered
from the La Brea Tar Pits in Los Angeles, the
authors of the study combined data from stable
oxygen isotope analyses, micro-computed
tomography, and previously published studies to
establish the eruption rate for the saber-toothed
cat’s permanent upper canines and to calculate
the timing of other growth events.
The authors of the study estimate that the permanent dentition of saber-toothed cats was fully
erupted by 14 to 22 months, with the exception of the upper canines. These weren’t fully
developed until about three years of age, which is delayed in comparison to similar-sized living
members of the cat family. The eruption rate of the saber-toothed cat’s permanent upper canines
was 6 millimeters per month—double the growth rate of an African lion’s teeth.
The researchers suggest that the technique used in the study could be applied to a variety of
extinct species to better understand the manner and rate by which different animals grew, for
example, by looking at the tusks of extinct elephants or marine mammals.
“Despite having canine crown heights that were more than twice those of the lion, it didn’t require
twice as much time to develop its canines,” added lead author Aleksander Wysocki.
Adapted by PLOS ONE from release provided by the author
In your coverage please use this URL to provide access to the freely available paper:
http://dx.plos.org/10.1371/journal.pone.0129847
Press-only preview: https://www.plos.org/wp-content/uploads/2013/05/pone-10-7-Wysocki
Contact: Robert Feranec, ph: 1 (518)474-5819, feranec@gmail.com,
robert.feranec@nysed.gov, Aleksander Wysocki, mwysock@clemson.edu
Citation: Wysocki MA, Feranec RS, Tseng ZJ, Bjornsson CS (2015) Using a Novel Absolute
Ontogenetic Age Determination Technique to Calculate the Timing of Tooth Eruption in the
Saber-Toothed Cat, Smilodon fatalis. PLoS ONE 10(7): e0129847.
doi:10.1371/journal.pone.0129847
Image Credit: Wysocki, Feranec, Tseng, and Bjornsson
Funding: Funding for this study was provided by the Society of Vertebrate Paleontology, U.C.
Berkeley Department of Integrative Biology, American Museum of Natural History’s Theodore
Roosevelt Grant, and an NSF DDIG to RSF. ZJT is supported by NSF DEB-1257572 and a Frick
postdoctoral fellowship from the American Museum of Natural History. Logistical support was
provided by the NY State Museum. The funders had no role in study design, data collection and
analysis, decision to publish, or preparation of the manuscript.
Competing Interests: The authors have declared that no competing interests exist.