Anthropologists at North Carolina State University found the differences in the craniofacial features of men and women have become less pronounced over the centuries, a university release reported Monday.
The researchers found that while craniofacial features for both sexes in Spain have changed over time, the changes have been particularly significant in females, with the facial structure of modern Spanish females considerably larger than that of 16th century women.
The difference may stem from improved nutrition or other environmental factors, the researchers say.
Researchers say studying structural differences between male and female skulls has importance because "this can help us establish the sex of the remains based on their craniofacial features," NCSU anthropologist Ann Ross says.
"This has applications for characterizing older remains," Ross said. "Applying 20th century standards to historical remains could be misleading, since sex differences can change over time -- as we showed in this study."
But the research has modern applications as well, she said, particularly when an incomplete skeleton missing the pelvic area or other distinctive feature is found.
"Being able to tell if a skull belonged to a man or woman is useful in both criminal investigation and academic research," Ross said.