Two hyperostotic non-metric traits, caroticoclinoid foramen and pterygospinous foramen, which appear at an early developmental stage in the human cranium

Hyperostotic non-metric traits of the human cranium are characterized by excessive ossification over the non-anomalous condition. Although hyperostotic traits are considered age-progressive, the appearance of two hyperostotic traits, hypoglossal canal bridging and jugular foramen bridging, has been reported in fetal crania. In the present study, we show the detection of a pterygospinous foramen and two caroticoclinoid foramina in Japanese fetal crania. These findings suggest that these two types of foramen can appear at an early stage of craniofacial development. Analysis of the Spitalfields skeletal collection (London) has shown that the frequencies of both foramina in adults older than 20 years of age were slightly higher than those of children aged 0-6 years. However, statistical analyses did not show significant differences between children and adults. This suggests that these non-metric cranial traits may also be useful for anthropological population studies of juveniles.