They are considered a common species in the region during the Holocene and Late Pleistocene (
Rancholabrean Land Mammal Age).
The fractured patterns observed on the Yukon bone fragments are sometimes found on proboscidean limb bone from faunal collections that are listed as being from the
Rancholabrean Land Mammal Age (LMA).
The
Rancholabrean Land Mammal Age is defined by the first appearance of Bison south of 55[degrees]N latitude and begins approximately 160,000 years BP (Bell et al., 2004).
Lauren Hall, School of Science and TechnologyCorpus Christi, "Pleistocene
Rancholabrean Large Mammalian Fauna from Aransas River, San Patricio County, TX"
American mastodons (Mammut americanum) have been recovered from late Pleistocene (
Rancholabrean) sediments across North America, with numerous occurrences in the southeast.
He presents morphometric data in detail and suggests that the population was already in a state of transition towards the larger size that characterized the later
Rancholabrean forms.
Teeth and post-cranial remains of Bison from throughout the deposits indicate that the Terapa local fauna represents the
Rancholabrean North American Land Mammal Age of the late Pleistocene.
The beautiful armadillo is known from the end of the Pliocene through the latest Pleistocene, exhibiting a temporal size increase that terminated with
Rancholabrean armadillos twice the size of the modern D.
There are at least 14
Rancholabrean fossil localities of M.
americanum phytoliths from Aucilla River (Pleistocene: late
Rancholabrean) in Florida are compared with Kansas mastodon phytoliths to determine possible regional differences in diet.
Several fossil collecting trips by the writer to Tesheva Creek in Yazoo County, Mississippi between the years of 1997-2001 have produced numerous fossil bones and teeth of Late Pleistocene (
Rancholabrean age) land mammals including mastodon, horse, tapir, mammoth, deer, and llama which are derived from the loess deposits of the area.