Craniofacial morphology of Adalatherium hui (Mammalia, Gondwanatheria) from the Late Cretaceous of Madagascar

December 18, 2020

David W. Krause (1,2), Simone Hoffmann (3), James B. Rossie (4), Yaoming Hu (2), John R. Wible (5), Guillermo W. Rougier (6), E. Christopher Kirk (7), Joseph R. Groenke (8)
Journal of Vertebrate Paleontology, 40, December 2020: 19-66. DOI: 10.1080/02724634.2020.1808665


The cranium of Adalatherium hui, as represented in the holotype and only specimen (UA 9030), is only the second known for any gondwanatherian mammal, the other being that of the sudamericid Vintana sertichi. Both Adalatherium and Vintana were recovered from the Upper Cretaceous (Maastrichtian) Maevarano Formation of northwestern Madagascar. UA 9030 is the most complete specimen of a gondwanatherian yet known and includes, in addition to the cranium, both lower jaws and a complete postcranial skeleton. Aside from Adalatherium and Vintana, gondwanatherians are otherwise represented only by isolated teeth and lower jaw fragments, belonging to eight monotypic genera from Late Cretaceous and Paleogene horizons of Madagascar, the Indian subcontinent, Africa, South America, and the Antarctic Peninsula. Although the anterior part of the cranium is very well preserved in UA 9030, the posterior part is not. Nonetheless, comparable parts of the crania of Adalatherium and Vintana indicate some level of common ancestry through possession of several synapomorphies, primarily related to the bony composition, articular relationships, and features of the snout region. Overprinted on this shared morphology are a host of autapomorphic features in each genus, some unique among mammaliaforms and some convergent upon therian mammals. The cranium of Adalatherium is compared with the crania of other mammaliamorphs, particularly those of allotherians or purported allotherians (i.e., haramiyidans, euharamiyidans, multituberculates, Cifelliodon, and Megaconus). Particular emphasis is placed on several recently described forms: the enigmatic Cifelliodon from the Early Cretaceous of Utah and several new taxa of euharamiyidans from the Late Jurassic of China.

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Author Affiliation

(1) Department of Earth Sciences, Denver Museum of Nature & Science, Denver, Colorado 80205, U.S.A.
(2) Department of Anatomical Sciences, Stony Brook University, Stony Brook, New York 11794-8081, U.S.A.
(3) Department of Anatomy, New York Institute of Technology, College of Osteopathic Medicine, Old Westbury, New York 11568, U.S.A.
(4) Department of Anthropology, Stony Brook University, Stony Brook, New York 11794-4364, U.S.A.
(5) Section of Mammals, Carnegie Museum of Natural History, 5800 Baum Boulevard, Pittsburgh, Pennsylvania 15206, U.S.A.
(6) Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, Kentucky 40202, U.S.A.
(7) Department of Anthropology and Vertebrate Paleontology Laboratory, Jackson School Museum of Earth History, University of Texas at Austin, Texas 78712, U.S.A.
(8) Department of Biomedical Sciences, Ohio University Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio 45701, U.S.A.