caa a22 4500 388017678 CHVBK 20180307124915.0 cr unu---uuuuu 161130e199805 xx s 000 0 eng 10.1017/S0022336000024306 doi S0022336000024306 pii (NATIONALLICENCE)cambridge-10.1017/S0022336000024306 Marsupial mammal from the Upper Cretaceous North Horn Formation, Central Utah [Elektronische Daten] [Richard L. Cifelli, Christian De Muizon] Little is known of the non-dinosaurian fauna from the Cretaceous (Maastrichtian) part of the North Horn Formation, despite its biogeographic importance. Herein we describe a new marsupial mammal from the unit, founded on an exceptionally complete specimen of a juvenile individual, and present new information on the incisor region of early marsupials, based on comparison with complete specimens from the early Paleocene of Bolivia. Alphadon eatoni, new species, is the smallest Lancian species of the genus, and departs from a presumed marsupial morphotype in having the second lower incisor enlarged. The species is, however, primitive in lacking a "staggered” pattern to the incisor series and in having a labial mandibular foramen, and in these respects it differs from Paleocene and later marsupials. Poor representation of other taxa precludes meaningful comparison to most other North American Cretaceous marsupials, although Eodelphis, thought to be distantly related, also has an enlarged i2. Although Alphadon is characterized by many primitive features, the relative development of the incisors is not what would be predicted in a morphological antecedent to later Marsupialia. Copyright © The Paleontological Society Cifelli Richard L. Oklahoma Museum of Natural History and Department of Zoology, University of Oklahoma, Norman 73019, <rlc@ou.edu> aut De Muizon Christian Laboratoire de Paléontologie-URA CNRS 12, Muséum National d'Histoire Naturelle, 8, rue Buffon, F-75005 Paris, France aut Journal of Paleontology Cambridge University Press 72/3(1998-05), 532-537 0022-3360 72:3<532 1998 72 JPA https://doi.org/10.1017/S0022336000024306 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1017/S0022336000024306 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Cifelli Richard L. Oklahoma Museum of Natural History and Department of Zoology, University of Oklahoma, Norman 73019, <rlc@ou.edu> aut NATIONALLICENCE 700 1- De Muizon Christian Laboratoire de Paléontologie-URA CNRS 12, Muséum National d'Histoire Naturelle, 8, rue Buffon, F-75005 Paris, France aut NATIONALLICENCE 773 0- Journal of Paleontology Cambridge University Press 72/3(1998-05), 532-537 0022-3360 72:3<532 1998 72 JPA CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge