indicate that they were left lying as modified natural resources, whether with benevolent intent or because they did not represent a sufficient investment of time and labor to justify transporting them ("opportunistic" tools). More simply, perhaps the users intended to return to the same area during the next year's mast-gathering period. The now traditional term "nutting stone" may be justified, as may "straightening stone" or "shaft-anchor" (for straightening arrow-shafts) within a larger class we might call "poculoliths" (<L. poculus, "small pocket", "cup"). While an equivalent to "pitted stone", the proposed term has the advantage of wider comprehensibility among international scholars as the worldwide distribution of the form becomes increasingly evident. Another interpretation of these structures is fossilization. Anatomical structures of the orbit, skull, joints, organs, antler and dental cavities are similar. Fragmentation may have occurred before or after fossilization, natural human smoothing and polishing. The structure becomes a ubiquitous, multipurpose tool for humans to exploit. Cupstone sites in Northern Italy, Switzerland and the Atlantic regions, also known as "druid altars" or "Opferkessel" (sacrificial bowl), are associated with places of worship due their locality close to glacial erratics, view points and treacherous alpine trails. Some of the prehistoric cupstone sites north of the Alps along the Jura mountains, for example near Grenchen, show a row of cups with possibly astronomical orientation. However, cupstones are usually not associated with calendar functions as this is sometimes the case with menhirs and megaliths. Omars Nutting stones can be very similar in appearance to omars. Omars are naturally formed stones that have hemispherical bubbles in them. See also Knocking stone References Archaic period in North America Archaeological artefact types Native American tools Lithics Primitive technology