Accessory navicular: A heritable accessory bone of the human foot

The accessory navicular is a supernumerary bone of the human foot located medial to the navicular tuberosity and represents a secondary center of ossification that has failed to fuse to the main body of the navicular. Three forms of the accessory bone have been identified: Type I is an independent ossicle that is often embedded within the tibialis posterior tendon; Type II is a triangular accessory bone that attaches to the navicular tuberosity by means of a cartilaginous or fibrocartilaginous bridge; and Type III represents a fused Type II, which forms a hook‐like protuberance extending from the tuberosity. The Type II accessory navicular is the most common of the three forms and is the most readily identifiable in skeletal material since it causes the navicular tuberosity to become abnormally flattened and porous. The purpose of this study was to describe the various manifestations of the accessory navicular in dry bone, to present and compare frequency data for several skeletal populations, and to consider questions of laterality and sex bias in trait expression. In total, the skeletons of 497 Danes, 460 Euro‐Americans, 300 African Americans, 100 Japanese, and 205 Europeans were examined for the presence of the Type II accessory navicular. Overall frequencies for the five groups ranged from 2% in the African American sample to 5% in the Japanese sample. Since several family pedigrees have documented the accessory navicular as being an inherited skeletal defect, the relatively low frequency found in the present study makes this trait a potentially useful indicator of genetic relatedness within archaeological cemeteries. In addition, the trait was found to occur more often unilaterally than bilaterally and there was nearly equal incidence among males and females. Copyright © 2010 John Wiley & Sons, Ltd.     

The demographic,socio‐economic and temporal contextualisation of the Universitat Autònoma de Barcelona collection of identified human skeletons (UAB collection)

Identified human skeletal collections are those in which basic demographic data (sex, age and biological origin) are known and are crucial for developing and testing osteological methodologies. It is important that the identified collection be contextualised, and in this way the collection will be considered a reference collection. To contextualise a collection requires documentation of the basic demographic data of the individuals (sex, age, year of birth, geographical area) as well as information concerning the socio‐economic and temporal context in which the individuals lived. The contextualisation of an identified collection is very important so the researchers can understand the ‘point of reference’ when applying a method to it or developing a new method. The purpose of this study is to contextualise the identified skeletal collection of the Universitat Autónoma de Barcelona (UAB) which currently contains 35 adult skeletons of both sexes. To carry out the objectives of the present study, the information about the individuals was collected from cemetery registers and compared with the information of the demographic and statistic public institutions of Spain. The results indicate that the UAB collection is formed only by Spanish nationals who mainly lived during the 20th century in Granollers (Barcelona, Spain). Both sexes are equally represented and all of the individuals are adults. They reflect the most current adult population structure of Catalonia and be treated as a Catalan reference sample of adults living in the 20th century. This collection offers special opportunities for demographic analysis, including validation studies of skeletal ageing and sexing methods that target adult individuals. The collection can also be used in conjunction with other reference samples to investigate secular and populational change in cranial form, sexual dimorphism and stature. Copyright © 2010 John Wiley & Sons, Ltd.