Discriminant function sexing of fragmentary and complete tibiae from medieval Croatian sites

Previous studies have demonstrated that populations differ from each other in size and proportion and that these differences can affect metric assessment of sex. This paper establishes standards for determining sex from fragmentary and complete tibiae in the medieval Croatian population. The sample is composed of 180 tibiae (96 males and 84 females) from six medieval archaeological sites in Croatia. Three of the sites were located in continental Croatia, three on the eastern Adriatic coast and its immediate hinterland. Six tibial dimensions were measured: (1) length of the tibia; (2) maximum epiphyseal breadth of the proximal tibia; (3) maximum epiphyseal breadth of the distal tibia; (4) maximum diameter of the tibia at the nutritient foramen; (5) transverse diameter of the tibia at the nutritient foramen; and (6) circumference of the tibia at the nutritient foramen. Unifactorial and multifactorial analyses were performed on the collected data. Six discriminant functions were generated, one using six variables, two using two variables, and three employing one variable. Results show that complete tibiae can be sexed with 92.2% accuracy. Slightly lower accuracies (91.7 and 87.8%) were achieved using a combination of two variables, while functions employing one variable were accurate from 85.6 to 81.7%. The results of this study show that the medieval Croatian tibia is a good skeletal component for determining sex. Standardized coefficients of the discriminant functions generated in this study support the results of previous studies that found that breadth dimensions provide better separation of the sexes than length.