Bison latifrons (Giant Ice Age Bison)
The largest bison with horns up to 7.5feet tall were herbivorous browsers/grazers that went extinct about 20,000-30,000 years ago. These bison thrived in North America and lived in small herds during the Pleistocene epoch for about 200,000 years before becoming extinct most likely due to a glaciation event that occurred during the Quaternary Extinction.
Capromeryx minor (dwarf pronghorn)
Capromeryx minor is a very small, extinct species of a pronghorn-like ungulate. The herbivore stood about only 60 cm tall and weighed about 22 pounds. They had two tined horns, giving them a four-horned appearance. Because of its small size, it most likely lived in forests where it hid. Specimens of this species dated to the late Irvingtonian and rancholabrean period, which is considered to overlap the late Pleistocene and middle Pleistocene epochs. The species was discovered in La Brea Tar Pits of California and has been found as far east as Texas. Little is known about this species but its extinction was most likely associated with environmental conflicts.
The western horse inhabited North America during the Ice Age, appearing to go extinct approximately 11,000 years ago. Their earliest fossils date to 500,000 years ago.They were a larger horse species, growing to about the size of a modern mustang and having a stout build. Though they are known as the western horse, their remains have been found all across the United States. As is characteristic of horse species, the western horse was a grazer. Their extinction appears to be a result of the ending of the Ice Age.
Euceratherium collinum (Shrub-ox)
A herbivorous browser/grazer that mainly fed on trees and shrubs. It is about the size of a cow and is native to North America. This species is considered a close relative of the musk-ox. It appeared on this continent in the early Pleistocene epoch. It went extinct about 11,500 years ago most likely due to environmental factors and climatic changes.
Homotherium serum is the less widely known saber-toothed cat. It had shorter saber-teeth that had serrated edges, long legs, non-retractible claws, a large nasal cavity, and was about the size of a modern lion.. It was most likely very fast and hunted in open habitats in packs. Homotherium serum was much less abundant than Smilodon and lived in higher latitudes and altitudes. It probably survived on a diet of large thick-skinned herbivores such as mammoths or mastodon. Its extinction in North America is approximated at 10,000 years ago.
Mammuthus columbi (Columbian mammoth)
The Columbian mammoth is one of the largest elephants to ever live, growing to sizes up to 13 feet tall and weighing up to 10 tons. The mammoth’s primary diet consisted of various grasses and conifers. They ranged across all of North America and as far south as Nicaragua. The date of their extinction is generally set at about 12,500 years ago but newer fossils have been found outside of California. Their extinction is generally attributed to either dramatic climate change or overhunting by the indigenous populations.
Panthera atrox (American Lion)
Panthera atrox, the American lion, was one of the largest felines in the world. It was approximately 25% larger than the modern African lion. It originated in North America and eventually colonized parts of South America. The American lion often lived in cold areas, using caves for shelter. They are thought to have preyed on deer, North American horses, bison, mammoths, and other large animals. The American lion went extinct around the same time as the other megafaunal extinctions during the Quaternary, which is when most species that it preyed on went extinct. Humans may have contributed to its extinction as well, as lion bones have been found in trash heaps of Paleolithic Indians.
Platygonus cf. P. compressus (flat headed peccaries)
Platygonus cf. P. compressus is the species name for flat headed peccaries that once lived from New York west to California. They also lived from Mexico north to the ice sheets, from the middle and late Rancholabrean. Their preferred habitat is open areas. This species was about the size of the European wild boar. Its rostrum was moderately elongated. It stood at roughly 30 inches tall at the shoulder and weighed approximately 50kg. This species of peccaries tended to live in herds inside caves. It went extinct during the end of the Pleistocene, probably due to marginal conditions because remains were found in groups within the caves. They were omnivores and tended to eat courser vegetation as opposed to shrubs because they lived in open areas.
Smilodon fatalis is the most well-known saber-toothed cat. It existed during the last ice age on the western coast of North America. Smilodon fatalis was about the size of a modern lion, except with a much more muscular build. It also had fron “saber” teeth, long canines that grew up to seven inches long. The muscular body of Smilodon fatalis suggests that it was slower but most powerful than other felines, which means it was probably an ambush predator. It preyed on a variety of large game such as bison, deer, horses, ground sloths, and mammoths. The saber-toothed cat went extinct at the end of the Pleistocene around 10,000 B.C., which was a time of extinction for many other large mammals. Its decline has been speculated to be human-induced, as saber-toothed cats may have been hunted extensively. There are other theories that suggest that the end of the ice age and subsequent climatic and vegetation changes caused its extinction.
Tapirus californicus (California tapir)
The Tapirus californicus lived in Coastal southern California approximately 50 million years ago. Its preferred habitat consists of forests, woodlands, and grasslands near rivers and lakes. This species had unique physical features: It had a stout body, short legs, and a large tapered head with a short muscular snout. Its front limbs had four toes while its hindlimbs had three toes. Its body weight was estimated to be around 225 kg. Its head along with body length was estimated to be 140 cm. The California tapir was believed to be solitary and non-territorial. It may have liked wallowing in the mud. The species went extinct roughly 13,000 years ago, probably due to the Ice Age. Its diet consisted of leaves, fruits, seeds, and aquatic plants.