A tall rostral hook in a medieval horse premolar tooth

Development of dental abnormalities due to improper occlusal wear is common among modern domestic horses. This phenomenon often is attributed to jaw conformation. Rostral mandibular hooks may develop in horses with underjet or mandibular prognathism, a condition where the lower jaw protrudes forward, beyond the upper jaw. Less abrasive diet, free of phytoliths and matrix-like plant fibers, also may promote enamel and focal overgrowths of equine dentition. Here we report a rostral mandibular hook in a lower premolar tooth of a medieval horse, found in a spring deposit in Levanluhta, Osthrobothnia, Finland. To our knowledge, this is the first such report from a medieval horse. (C) 2017 Elsevier Inc. All rights reserved.Peer reviewe

Excess protein enabled dog domestication during severe Ice Age winters

Peer reviewe

Excess protein enabled dog domestication during severe Ice Age winters

International audienceDogs (Canis familiaris) are the first animals to be domesticated by humans and the only ones domesticated by mobile hunter-gatherers. Wolves and humans were both persistent, pack hunters of large prey. They were species competing over resources in partially overlapping ecological niches and capable of killing each other. How could humans possibly have domesticated a competitive species? Here we present a new hypothesis based on food/resource partitioning between humans and incipient domesticated wolves/dogs. Humans are not fully adapted to a carnivorous diet; human consumption of meat is limited by the liver’s capacity to metabolize protein. Contrary to humans, wolves can thrive on lean meat for months. We present here data showing that all the Pleistocene archeological sites with dog or incipient dog remains are from areas that were analogous to subarctic and arctic environments. Our calculations show that during harsh winters, when game is lean and devoid of fat, Late Pleistocene hunters-gatherers in Eurasia would have a surplus of animal derived protein that could have been shared with incipient dogs. Our partitioning theory explains how competition may have been ameliorated during the initial phase of dog domestication. Following this initial period, incipient dogs would have become docile, being utilized in a multitude of ways such as hunting companions, beasts of burden and guards as well as going through many similar evolutionary changes as humans