Xenosmilus
Encyclopedia
Xenosmilus is a genus
of extinct Machairodontinae
, or saber-toothed cat
. Two fairly intact specimens were found by amateur fossil
hunters, in 1983 (1981 by some sources) in the Haile limestone mines in Alachua County
, Florida
. In 1994 the fossils were examined, and it was decided that the cats were of an entirely new genus, which has been placed under the tribe Machairodontini
. They lived about 1 million years ago, but as there are only two specimens of the same age, when they appeared and when they became extinct is unclear. Currently, there is only one species known, X. hodsonae.
Physically, the cat measured between 1.7-1.8 m long with a highly muscular
body, even more muscular than any other cat alive or dead, and the animal probably weighed around 230-400 kg
. Before their discovery, all known saber-toothed cats fell into two general categories. Dirk toothed cats had long upper canines
and stout legs. Scimitar toothed cats had only mildly elongated canines, and long legs. Xenosmilus broke these groupings by possessing both stout muscular legs and body, and short broad upper canines.
Found alongside the two skeletons were dozens of peccary
bones. It seems likely, with their muscular builds, that X. hodsonae preyed upon peccaries in life.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of extinct Machairodontinae
Machairodontinae
Machairodontinae is an extinct carnivoran mammal subfamily of Felidae endemic to Asia, Africa, North America, South America, and Europe from the Miocene to Pleistocene living from c. 23 Ma until c...
, or saber-toothed cat
Saber-toothed cat
Saber-toothed cat or Sabre-toothed cat refers to the extinct subfamilies of Machairodontinae , Barbourofelidae , and Nimravidae as well as two families related to marsupials that were found worldwide from the Eocene Epoch to the end of the Pleistocene Epoch ,...
. Two fairly intact specimens were found by amateur fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
hunters, in 1983 (1981 by some sources) in the Haile limestone mines in Alachua County
Alachua County, Florida
Alachua County is a county located in the U.S. state of Florida. The U.S. Census Bureau 2006 estimate for the county is 227,120. Its county seat is Gainesville, Florida. Alachua County is the home of the University of Florida and is also known for its diverse culture, local music, and artisans...
, Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
. In 1994 the fossils were examined, and it was decided that the cats were of an entirely new genus, which has been placed under the tribe Machairodontini
Machairodontini
Machairodontini is an extinct tribe of large saber-toothed cats of the subfamily Machairodontinae, that lived in Europe, Asia, Africa, North America, and South America during the Miocene through Pleistocene living from 11.6 mya–11 000 years ago.-Taxonomy:Machairodontini was named...
. They lived about 1 million years ago, but as there are only two specimens of the same age, when they appeared and when they became extinct is unclear. Currently, there is only one species known, X. hodsonae.
Physically, the cat measured between 1.7-1.8 m long with a highly muscular
Muscle
Muscle is a contractile tissue of animals and is derived from the mesodermal layer of embryonic germ cells. Muscle cells contain contractile filaments that move past each other and change the size of the cell. They are classified as skeletal, cardiac, or smooth muscles. Their function is to...
body, even more muscular than any other cat alive or dead, and the animal probably weighed around 230-400 kg
Kilogram
The kilogram or kilogramme , also known as the kilo, is the base unit of mass in the International System of Units and is defined as being equal to the mass of the International Prototype Kilogram , which is almost exactly equal to the mass of one liter of water...
. Before their discovery, all known saber-toothed cats fell into two general categories. Dirk toothed cats had long upper canines
Canine tooth
In mammalian oral anatomy, the canine teeth, also called cuspids, dogteeth, fangs, or eye teeth, are relatively long, pointed teeth...
and stout legs. Scimitar toothed cats had only mildly elongated canines, and long legs. Xenosmilus broke these groupings by possessing both stout muscular legs and body, and short broad upper canines.
Found alongside the two skeletons were dozens of peccary
Peccary
A peccary is a medium-sized mammal of the family Tayassuidae, or New World Pigs. Peccaries are members of the artiodactyl suborder Suina, as are the pig family and possibly the hippopotamus family...
bones. It seems likely, with their muscular builds, that X. hodsonae preyed upon peccaries in life.