Abstract: Objective To study the morphological characteristics of femurs of adult human and 11 kinds of adult animals from cattle, horses, pigs, goats, sheep, dogs, cats, rabbits, geese, ducks, chickens, and to establish an effective species identification method among various species. Methods The 4 cm mid-diaphyseal segment of the femur from adult human （older than 20 years old） at autopsy was obtained. Additionally, the 4 cm ones from 11 kinds of adult animals were obtained. After decalcification, all femurs were made into slices, and then were observed by optical microscope. The 25 indexes were selected and analyzed by step discriminant analysis according to differences between human and mammal, human and poultry, and human and 11 kinds of animals. Results The histological structure of bone mineral density of middle part of femur had obvious characteristics among the species. And the morphology and number of osteon showed the trend of obvious biological evolution. There were 11 indexes with significant differences between human and 11 kinds of animals to establish some mathematical models to discriminate all species. The correct discrimination rate was 96.3% between human and mammal. The correct discrimination rate was up to 100% between human and poultry, and was 89.4% among human, mammal and poultry. Conclusion The mathematical models have good correct discrimination rate among human and the other animals, which could be applied in the practical species identification cases.

Key words: forensic anthropology, femur, humans, mammals, poultry, species identification