A new Haramiyid indicating a complex pattern of evolution in Mesozoic mammals
A major unsolved problem in mammalian evolution is the origin of Allotheria, including Multituberculata and Haramiyida. Multituberculates are the most diverse and best known Mesozoic era mammals and ecologically resemble rodents, but haramiyids are known mainly from isolated teeth, hampering our search for their phylogenetic relationships. Researchers from Institute of Vertebrate Paleontology and Paleoanthropology (IVPP), Chinese Academy of Sciences, Shandong Tianyu Museum of Nature and Linyi University, reported a new haramiyid from the Jurassic period of China, Arboroharamiya jenkinsi, a partial skeleton with both mandibles associated with teeth and isolated upper teeth. This largest known haramiyid reveals additional mammalian features of this group, and helps to identify other haramiyids represented by isolated teeth, indicating a complex pattern of evolution involving many convergences and/or reversals existed in Mesozoic mammals, as reported August 8 in Nature.