The development of the vermiculate pattern in the brow region of crania from Indian Knoll, Kentucky.

A convoluted brow surface consisting of fine ridges, grooves, and depressions, first identified in ancient fossil hominids and termed the vermiculate pattern (VP), is often low in frequency and of moderate rugosity in crania of anatomically modern human populations. Burials at Indian Knoll, Kentucky, constitute an excellent series for study of the development of the VP, since cranial surfaces are usually well preserved, there are hundreds of immature and mature individuals previously assessed for age, and the VP is high in frequency and rugosity. While a surface pattern resembling a miniature VP is found on the supraorbital surface of all newborns, it is not found on any children age 2 or older. This newborn pattern is probably different in structure and origin from the adult VP. The smooth surface characteristic of children shows evidence of changing to the VP in some adolescents, but the fullest development of the VP occurs in adults. The VP continues to develop in rugosity into the fourth decade, especially in males. These observations indicate that the human VP is different in etiology from somewhat similar brow surfaces found sporadically in immature individuals of some species of nonhuman primates. Statements lumping all vermiculate bone surfaces as "fine cancellous bone" are premature. The human VP development shows no apparent relationship to phases of tooth eruption, as postulated for the appearance of areolar surfaces on brow ridges of immature non-human primates.