Center for the Study of the First Americans, Texas A&M University, College Station, TX 77843-4352, USA.
Department of Anthropology, Texas A&M University, College Station, TX 77843-4352, USA.
Sci Adv. 2018 Oct 24;4(10):eaat4505. doi: 10.1126/sciadv.aat4505. eCollection 2018 Oct.
Lanceolate projectile points of the Clovis complex and stemmed projectile points of the Western Stemmed Tradition first appeared in North America by ~13 thousand years (ka) ago. The origin, age, and chronological superposition of these stemmed and lanceolate traditions are unclear. At the Debra L. Friedkin site, Texas, below Folsom and Clovis horizons, we find stemmed projectile points dating from ~13.5 to ~15.5 ka ago, with a triangular lanceolate point form appearing ~14 ka ago. The sequential relationship of stemmed projectile points followed by lanceolate forms suggests that lanceolate points are derived from stemmed forms or that they originated from two separate migrations into the Americas.
克莱维斯复合文化中的披针形投射器和西部茎状投射器传统中的有茎投射器最早于约 13000 年前出现在北美洲。这些茎状和披针形传统的起源、年代和年代顺序尚不清楚。在德布拉·L·弗里德金遗址(位于德克萨斯州),我们发现有茎投射器的年代可以追溯到约 13500 到 15500 年前,其中一种三角形的披针形形式出现在约 14000 年前。有茎投射器先于披针形形式出现的顺序关系表明,披针形投射器是从有茎投射器衍生而来,或者它们是从两个不同的方向进入美洲的。