Reconstructing the functional traits of the horses from the tomb of King Childeric

The Merovingian period sees the emergence of the saddle horse as a critical component of the military forces. This increased importance is generally thought to be associated with a particular attention paid to horse breeding, which contributed to preserve the large size they acquired during Roman period. In spite of the Early Middle Ages being considered as a turning point in the history of their usage in Western Europe, its impact on the morphological traits of the horses remain largely unexplored. Privilege of the warrior elite, the horse is also a marker of social rank when associated to human burials. The royal tomb of Childeric the 1st (Tournai, Belgium), considered as the most lavish of the western Germanic world, revealed the presence of twenty-one skeletons of equids, deposited in peripheral pits. Here we use 3D geometric morphometrics to characterize the morphological traits and possible function of these equids using shape variation and covariation analyses of the limb bones. We found close phenotypic proximities with modern racehorse specimens. However, differences in magnitude of morphological integration between them suggest specificities in the functional features of the archaeological horses and probably reflect variation in the degree of artificial selection. Our results demonstrate the importance of accurately exploring the complete shape of bones to describe the morphological characteristics of past animals. Our results also illustrate the interest of not only investigating shape variation, but also covariation patterns, in order to address functional questions and in trying to detect possible markers of artificial selection on past horses.1 Introduction 2 Material and methods 2.1 Material 2.2 Acquisition of data and geometric morphometrics 2.3 Species classification 2.4 Shape variation 2.5 Shape covariation 2.5.1 Visualization of covariation patterns 2.5.2 Magnitude of morphological integration 2.5.2 Magnitude of morphological integration 3 Results 3.1 Classification 3.2 Shape variation 3.2.1 Shape variance 3.2.2 Morphological comparison with extant breeds 3.3 Shape covariation 3.3.1 Visualization of covariation patterns 3.3.2 Magnitude of morphological integration 4 Discussion 5 Conclusio