title: Three new Jurassic euharamiyidan species reinforce early divergence of mammals.
abstract: The phylogeny of Allotheria, including Multituberculata and Haramiyida, remains unsolved and has generated contentious views on the origin and earliest evolution of mammals. Here we report three new species of a new clade, Euharamiyida, based on six well-preserved fossils from the Jurassic period of China. These fossils reveal many craniodental and postcranial features of euharamiyidans and clarify several ambiguous structures that are currently the topic of debate. Our phylogenetic analyses recognize Euharamiyida as the sister group of Multituberculata, and place Allotheria within the Mammalia. The phylogeny suggests that allotherian mammals evolved from a Late Triassic (approximately 208 million years ago) Haramiyavia-like ancestor and diversified into euharamiyidans and multituberculates with a cosmopolitan distribution, implying homologous acquisition of many craniodental and postcranial features in the two groups. Our findings also favour a Late Triassic origin of mammals in Laurasia and two independent detachment events of the middle ear bones during mammalian evolution.
authors.affiliation: 1] Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China [2] Department of Biology, Indiana University of Pennsylvania, Indiana, Pennsylvania 15705, USA.
authors.forename: Shundong
authors.initials: S
authors.lastname: Bi
authors.affiliation: Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China.
authors.forename: Yuanqing
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Beijing Natural History Museum, 126 Tianqiao Street, Dongcheng District, Beijing 100050, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Guan
authors.affiliation: Paleontological Museum of Liaoning, Shenyang Normal University, Shenyang, Liaoning 110034, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Sheng
authors.affiliation: Division of Paleontology, American Museum of Natural History, Central Park West at 79th Street, New York, New York 10024, USA.
authors.forename: Jin
authors.initials: J
authors.lastname: Meng
mesh_terms: D000818:Animals; D002681:China; D005580:Fossils; D008322:Mammals / Q000033:anatomy & histology* / Q000145:classification*; D008334:Mandible / Q000033:anatomy & histology; D010802:Phylogeny; D012863:Skeleton; D012886:Skull / Q000033:anatomy & histology; D014070:Tooth / Q000033:anatomy & histology