A sumatralith is an

oval An oval () is a closed curve in a plane which resembles the outline of an egg. The term is not very specific, but in some areas of mathematics (projective geometry, technical drawing, etc.), it is given a more precise definition, which may inc ...

rectangular In Euclidean plane geometry, a rectangle is a rectilinear convex polygon or a quadrilateral with four right angles. It can also be defined as: an equiangular quadrilateral, since equiangular means that all of its angles are equal (360°/4 = 90 ...

shaped

stone In geology, rock (or stone) is any naturally occurring solid mass or aggregate of minerals or mineraloid matter. It is categorized by the minerals included, its Chemical compound, chemical composition, and the way in which it is formed. Rocks ...

artefact made by unifacially flaking around the

circumference In geometry, the circumference () is the perimeter of a circle or ellipse. The circumference is the arc length of the circle, as if it were opened up and straightened out to a line segment. More generally, the perimeter is the curve length arou ...

of a cobble. It is often used to infer the

Hoabinhian The Hoabinhian is a lithic techno-complex of archaeological sites associated with assemblages in Southeast Asia from the late Pleistocene to the Holocene, dated to –2000 BCE. It is attributed to hunter-gatherer societies of the region whose te ...

character of a lithic assemblage.

References

* Nishimura M. 1994. Attribute analysis of the Hoabinhian industry: Implications from a comparative study of Bung cave and Xom Trai cave, Northern Vietnam. ''Vietnam Social Sciences'' 5: 75-87 * Van Tan, H. A. (1997). The Hoabinhian and before. Bulletin of the Indo-Pacific Prehistory Association, 16, 35–41. Lithics {{archaeology-stub