Complex sentence: The proborhyaenids were characterized by a large and massive skull with molars specialized in meat consumption (carnassials) and their canines lacked of teeth enamel in preserved specimens; Marshall, L. "Evolution of the Borhyaenidae, extinct South American predaceous marsupials".
Split into simpler sentences: The proborhyaenids were characterized by a large and massive skull with molars specialized for meat consumption (carnassials). Preserved specimens of their canines lack enamel; Marshall, L. "Evolution of the Borhyaenidae, extinct South American predaceous marsupials".