New specimens, including the first record of lower dental plates, of the extinct myliobatid Myliobatis wurnoensis were recovered from the Maastrichtian (Late Cretaceous) of the Iullemmeden Basin, Mali, and are the oldest record of the taxon. We evaluated the phylogenetic position of this taxon with reference to other myliobatids (extinct and extant) using osteology and dentition. Our results indicate that Myliobatinae and Myliobatis are each paraphyletic, and that Aetobatus and Rhinoptera are monophyletic. We also found that taxa known only from the Cretaceous, Brachyrhizodus and Igdabatis, are highly nested within Myliobatidae. The phylogenetic position of these taxa unambiguously extends the origin of Myliobatidae and most of its representative taxa into the Mesozoic.

Key words: Chondrichthyes, Myliobatidae, Myliobatiformes, dentition, batoid, ghost lineage, phylogeny, Cretaceous, Maastrichtian, Mali.

Kerin M. Claeson, [kclaeson@mail.utexas.edu], Department of Geological Sciences, The University of Texas at Austin, Austin, 78712-0254, Texas, USA; Maureen A. O’leary [maureen.oleary@stonybrook.edu], Department of Anatomical Sciences, Stony Brook University, Stony Brook, 11794, New York, USA; Eric M. Roberts [robertse@suu.edu], Department of Physical Science, Southern Utah University, Cedar City, 84720, Utah, USA; Famory Sissoko, Institut des Sciences Humaines, Bamako, Mali (passed away); Mamadou Bouaré École [bouamala@yahoo.fr], Nationale des Ingénieurs, Bamako, Mali; Leif Tapanila [tapaleif@isu.edu], Department of Geosciences, Idaho State University, Pocatello, 83209-8072, Idaho, USA; David Goodwin [goodwind@denison.edu], Department of Geosciences, Denison University, Granville, 43023, Ohio, USA; Michael D. Gottfried [gottfrie@msu.edu], Department of Geological Sciences and Museum, Michigan State University, East Lansing, 48824, Michigan, USA.