Temporal and Geographic Variability in Projectile Points

It did not take long following the introduction of the Berkeley typological system for debate to ensue. Aikens (Reference Aikens1970) was the first to argue that large corner-notched points (i.e., Elko points) appeared earlier in the eastern Great Basin than in the western Great Basin. Thomas (Reference Thomas1981) acknowledged this and other issues when he proposed the MVK, and he was careful to point out its limitations in time and space. He cautioned that “the Monitor Valley classification is hardly infallible, and undoubtedly becomes fuzzy the further one travels from Monitor Valley” (Thomas Reference Thomas1981:37). Furthermore, it did not include pre-Mazama (i.e., late Pleistocene and early Holocene) point types because they were limited in the Monitor Valley sample.Footnote ¹ Despite Schroedl’s (Reference Schroedl2025:347) assertation that Thomas implied that the MVK was well suited for use across the Great Basin and Colorado Plateau, a careful reading of his article indicates this is not the case.Footnote ² On this, he was clear: “We must be certain to restrict this typology to the central and western Great Basin areas” (Thomas Reference Thomas1981:37).

Following publication of the MVK, additional discoveries of projectile points in well-dated contexts beyond Monitor Valley, improvements in radiocarbon dating, and studies of point morphology highlighted that (as Thomas [Reference Thomas1981] cautioned) the MVK is best suited for the central Great Basin. The proposed Thomas (Reference Thomas1981) unilineal sequence of projectile-point series tends to vary—either in the ages or geographic distributions of the point types that comprise them—as one moves away from central Nevada. In some places, there are also point types that Thomas (Reference Thomas1981) did not encounter in his study area (see Schroedl Reference Schroedl2025:Table 1). But we have known this for decades; it is not a new discovery, and Schroedl’s (Reference Schroedl2025) presentation of it as such seems disingenuous.

Projectile-Point Types and Series Are Working Approximations, Not Final Products

As Thomas (Reference Thomas2013:133) has noted, projectile-point typologies are works in progress, not final products. Additional chronology building and typology refinement have improved our understanding of the MVK’s utility and limitations. In many cases (e.g., Keene Reference Keene2018; Largaespada Reference Largaespada and Brian2006; Martin et al. Reference Martin, Coltrain and Codding2017; O’Connell and Inoway Reference O’Connell and Inoway1994; Pendleton Reference Pendleton and Thomas1985, Reference Pendleton and Thomas2020; Smith et al. Reference Smith, Barker, Hattori, Raymond and Goebel2013), chronology building has reaffirmed the ages of MVK types or series. In others (e.g., Coulam Reference Coulam2022), it has demonstrated that point types subsumed within a series differ in age or geographic distribution. In a few cases (e.g., Hildebrandt and King Reference Hildebrandt, King and McGuire2002; Hockett and Spidell Reference Hockett and Spidell2022), it has prompted researchers to propose new types. That our understanding of projectile-point variability has evolved should not mean that we abandon its foundation. Projectile-point series and chronology remain useful constructs. They allow researchers to order surface sites in time and address myriad questions related to social and economic organization across broad geographic areas (e.g., Hildebrandt et al. Reference Hildebrandt, McGuire, King, Ruby and Young2016; Smith Reference Smith2010; Thomas Reference Thomas2013, Reference Thomas2024:52–97). Often, studies using projectile points as time markers converge to highlight significant diachronic shifts in human behavior. Projectile-point series and chronology also remain important in efforts to assess the stratigraphic integrity of archaeological deposits, even when radiocarbon dates are available (Keene Reference Keene2018; Rosencrance et al. Reference Rosencrance, Jazwa, Smith and Mueller2023; Smith et al. Reference Smith, Felling, Taylor and Layton2015). Consequently, Schroedl’s (Reference Schroedl2025:354) assertion that Great Basin projectile point series are “artificial groupings that have no archaeologically interpretive value” is simply wrong. Are they imperfect, and should they be the subject of continued refinement? Of course. Should we abandon decades of research? We think not.

Failure to Provide an Alternative Is Failure to Move the Conversation Forward

Science advances when researchers offer alternatives to the status quo. Schroedl (Reference Schroedl2025) has highlighted issues of which scholars have long been aware. To address them, he has called for research that has been ongoing for decades. But he stops short of proposing a viable alternative beyond abandoning the projectile-point-series concept and chronology. In our opinion, the series concept has generated valuable knowledge. Its continued use and improvement of our understanding of variability across a huge geographic region are not mutually exclusive. Calling for the retirement of the series concept and chronology without proposing a replacement fails to advance the conversation.