Crescents are a distinctive component of several terminal Pleistocene–early Holocene (TP–EH) toolkits in the Far West, including the concave-based projectile point techno-complex, as demonstrated by archaeological associations, toolstone preferences, and manufacturing techniques. Archaeological and paleoenvironmental evidence suggests regular association with periods of wetland expansion across this region. Numerous speculative hypotheses have been proposed for the possible function(s) of these tools, but little direct investigation or testing has been conducted. This study uses the method of multiple working hypotheses to investigate these competing propositions. It draws on multiple lines of evidence from morphological and techno-functional patterns of tool damage and rejuvenation developed from a large artifact assemblage; analogs from ethnographic, historic, and archaeological cases; paleoenvironmental and ecological observations; an actualistic experimental program; and applications of foraging and design theories. Results show how morphological variation often reflects original blank form and individual tool life-history. Patterned recycling strategies include occasional manufacture from concave-base projectile points and conversion into gravers. The combined evidence best supports the hypothesized interpretation of lunate crescents as specialized transverse projectile points used primarily for open-water hunting of waterfowl by early foragers of the Great Basin and California, especially during episodic and localized increases in their abundance. These conclusions contribute to the growing picture of diversity and adaptive flexibility among early foragers in the Far West and further indicate waterfowl as a significant but temporally and spatially variable dietary component.

新月是远西地区几个更新世末期-全新世早期（TP-EH）工具包的独特组成部分，包括基于凹面的射弹点技术复合体，考古学协会、工具石偏好和制造技术证明了这一点。考古和古环境证据表明，该区域与湿地扩张时期有规律的联系。对于这些工具的可能功能，人们提出了许多推测性假设，但很少进行直接调查或测试。本研究使用多重工作假设的方法来研究这些相互竞争的命题。它从大型人工制品组合中开发的工具损坏和复兴的形态和技术功能模式中汲取了多种证据；来自民族志、历史和考古案例的类比；古环境和生态观测；现实的实验计划；以及觅食和设计理论的应用。结果表明形态变化通常如何反映原始毛坯形式和个体工具的生命史。图案化的回收策略包括偶尔从凹底射弹点进行制造并转化为雕刻机。综合证据最好地支持了对月牙新月作为专门的横向抛射点的假设解释，主要用于大盆地和加利福尼亚州的早期觅食者在开放水域捕猎水禽，特别是在其数量偶尔和局部增加期间。 这些结论有助于进一步了解远西​​部早期觅食者的多样性和适应性灵活性，并进一步表明水禽是重要但随时间和空间变化的饮食成分。