First cranial remains of a gondwanatherian mammal reveal remarkable mosaicism.
Previously known only from isolated teeth and lower jaw fragments recovered from the Cretaceous and Palaeogene of the Southern Hemisphere, the Gondwanatheria constitute the most poorly known of all major mammaliaform radiations. Here we report the discovery of the first skull material of a gondwanatherian, a complete and well-preserved cranium from Upper Cretaceous strata in Madagascar that we assign to a new genus and species. Phylogenetic analysis strongly supports its placement within Gondwanatheria, which are recognized as monophyletic and closely related to multituberculates, an evolutionarily successful clade of Mesozoic mammals known almost exclusively from the Northern Hemisphere. The new taxon is the largest known mammaliaform from the Mesozoic of Gondwana. Its craniofacial anatomy reveals that it was herbivorous, large-eyed and agile, with well-developed high-frequency hearing and a keen sense of smell. The cranium exhibits a mosaic of primitive and derived features, the disparity of which is extreme and probably reflective of a long evolutionary history in geographic isolation.
Department of Anatomical Sciences, Stony Brook University, Stony Brook, New York 11794, USA.
David W
DW
Krause
Department of Anatomical Sciences, Stony Brook University, Stony Brook, New York 11794, USA.
Simone
S
Hoffmann
Section of Mammals, Carnegie Museum of Natural History, 5800 Baum Boulevard, Pittsburgh, Pennsylvania 15206, USA.
John R
JR
Wible
Department of Anthropology, University of Texas at Austin, Austin, Texas 78712, USA.
E Christopher
EC
Kirk
Steinmann-Institut für Geologie, Mineralogie und Paläontologie der Universität Bonn, D-53115 Bonn, Germany.
Julia A
JA
Schultz
Steinmann-Institut für Geologie, Mineralogie und Paläontologie der Universität Bonn, D-53115 Bonn, Germany.
Wighart
W
von Koenigswald
Department of Anatomical Sciences, Stony Brook University, Stony Brook, New York 11794, USA.
Joseph R
JR
Groenke
Department of Anthropology, Stony Brook University, Stony Brook, New York 11794, USA.
James B
JB
Rossie
1] Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio 45701, USA [2] Ohio Center for Ecology and Evolutionary Studies, Ohio University, Athens, Ohio 45701 USA.
Patrick M
PM
O'Connor
Department of Anatomical Sciences, Stony Brook University, Stony Brook, New York 11794, USA.
Erik R
ER
Seiffert
Department of Biology, 221 Morrill Science Center, University of Massachusetts, Amherst, Massachusetts 01003, USA.
Elizabeth R
ER
Dumont
1] Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio 45701, USA [2] Ohio Center for Ecology and Evolutionary Studies, Ohio University, Athens, Ohio 45701 USA.
Waymon L
WL
Holloway
Geology Department, Macalester College, 1600 Grand Avenue, St Paul, Minnesota 55105, USA.
Raymond R
RR
Rogers
Département de Géologie, Université d'Antananarivo, Antananarivo (101), Madagascar.
Lydia J
LJ
Rahantarisoa
Department of Anthropology, University of Texas at Austin, Austin, Texas 78712, USA.
Addison D
AD
Kemp
Département de Paléontologie, Université d'Antananarivo, Antananarivo (101), Madagascar.
Haingoson
H
Andriamialison
D000818:Animals; D005580:Fossils; D060434:Herbivory; D008322:Mammals; D009030:Mosaicism; D010802:Phylogeny; D012886:Skull / Q000033:anatomy & histology*; D013045:Species Specificity; D014070:Tooth / Q000033:anatomy & histology