Unexpected morphological diversity in ancient dogs compared to modern relatives

The Neolithic transition to farming may have resulted in an early morphological diversification as a result of changes in the anthropic environment or intentional selection on specific morphologies. Here, we explore the variability and modularity in mandible form by comparing 525 dog mandibles from European archaeological sites ranging from 8,100 to 3,000 cal.

BC to a reference sample of modern dogs, wolves, and dingoes. We use three-dimensional geometric morphometrics to quantify the form of complete and fragmented mandibles. We demonstrate that an important morphological variability already existed before the Bronze Age in Europe, yet the largest, smallest, most brachycephalic or dolichocephalic extant dogs have no equivalent in the archaeological sample, resulting in a lower variation compared to modern relatives.