1CONICET, Divisio´n Antropologı´a, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata,
Paseo del Bosque s/n. La Plata 1900, Argentina
2Department of Anthropology, University of Nevada Reno, Reno, NV 89557
3School of Human Evolution and Social Change, Arizona State University, Tempe, AZ 85287-2402
KEY WORDS dental morphology; first maxillary premolars; nonmetric traits; Native Americans
ABSTRACT The Uto-Aztecan premolar (UAP) is a
dental polymorphism characterized by an exaggerated distobuccal
rotation of the paracone in combination with the
presence of a fossa at the intersection of the distal occlusal
ridge and distal marginal ridge of upper first premolars.
This trait is important because, unlike other dental variants,
it has been found exclusively in Native American
populations. However, the trait’s temporal and geographic
variation has never been fully documented. The discovery
of a Uto-Aztecan premolar in a prehistoric skeletal series
from northern South America calls into question the presumed
linguistic and geographic limits of this trait. We
examined published and unpublished data for this rare
but highly distinctive trait in samples representing over
5,000 Native Americans from North and South America.
Our findings in living Southwest Amerindian populations
corroborate the notion that the variable goes beyond the
bounds of the Uto-Aztecan language family. It is found in
prehistoric Native Americans from South America, eastern
North America, Northern and Central Mexico, and in living
and prehistoric populations in the American Southwest
that are not members of the Uto-Aztecan language
stock. The chronology of samples, its geographic distribution,
and trait frequencies suggests a North American origin
(Southwest) for UAP perhaps between 15,000 BP and
4,000 BP and a rapid and widespread dispersal into South
America during the late Holocene. Family data indicate
that it may represent an autosomal recessive mutation
that occurred after the peopling of the Americas as its geographic
range appears to be limited to North and South Amerindian populations.
WHOLE ARTICLE: http://www.unr.edu/Documents/liberal-arts/anthropology/Scott/Delgado
Am J Phys Anthropol 143:570–578, 2010. VVC 2010 Wiley-Liss, Inc.
