{{Short description|Extinct family of mammals}} {{about|the fossil mammalian genus|the given name|Leonardus (name)}} {{Italic title}} {{Automatic taxobox |name = ''Leonardus'' |fossil_range = Late Santonian-Maastrichtian<br>~{{fossil range|84|66}} |image = |image_caption = ''Leonardus'' (top left), alongside other meridiolestidan taxa |taxon = Leonardus |authority = Bonaparte 1990 |display_parents = 3 |type_species = '''''Leonardus cuspidatus''''' |type_species_authority = Bonaparte 1990 }}
'''''Leonardus''''' is an extinct mammal genus from the Late Cretaceous (Late Santonian to Maastrichtian) of South America.<ref name=FWLeonardus>[https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=204742 ''Leonardus''] at Fossilworks.org</ref> It is a meridiolestidan, closely related to the also Late Cretaceous ''Cronopio'' and the Miocene ''Necrolestes''.<ref name="Guillermo W. Rougier 2012">Guillermo W. Rougier, John R. Wible, Robin M. D. Beck and Sebastian Apesteguía (2012). "The Miocene mammal Necrolestes demonstrates the survival of a Mesozoic nontherian lineage into the late Cenozoic of South America". Proceedings of the National Academy of Sciences of the United States of America. 109 (49): 20053–20058. doi:10.1073/pnas.1212997109.</ref><ref name="Alexander O. Averianov 2013">Alexander O. Averianov, Thomas Martin and Alexey V. Lopatin (2013). "A new phylogeny for basal Trechnotheria and Cladotheria and affinities of South American endemic Late Cretaceous mammals". Naturwissenschaften. 100 (4): 311–326. doi:10.1007/s00114-013-1028-3.</ref>
== Description == ''Leonardus'' is a fairly small mammal, similar in size to ''Necrolestes''. It is known from two specimens, the holotype '''MACN-RN 172''', composed of a left maxilla, four associated molariform teeth and two pairs of alveoli, and '''MACN-RN 1907''', a right mandible with two molariforms. Said molariforms are vaguely peg-like, with a dome-like stylocone.
== Discovery == ''Leonardus'' is currently only known from the Los Alamitos Formation, Argentina. The holotype was found in 1990, while the second specimen was described more recently in 2010. The genus name honours the Italian paleontologist Giuseppe Leonardi.
== Classification == ''Leonardus'' was originally referred to Dryolestidae, but the lack of a parastylar hook on the molariforms, as well as a few features of the stylocone, suggest that it was grouped with other South American and African species at the exclusion of Laurasian species, in a clade known as Meridiolestida.<ref name="ReferenceA">Laura Chornogubsky, New remains of the dryolestoid mammal Leonardus cuspidatus from the Los Alamitos Formation (Late Cretaceous, Argentina), Article in Paläontologische Zeitschrift 85(3):343-350 · September 2011 DOI: 10.1007/s12542-010-0095-4</ref> Within Meridiolestida, it consistently groups with ''Necrolestes'' and ''Cronopio''.<ref name="Guillermo W. Rougier 2012"/><ref name="Alexander O. Averianov 2013"/>
== Paleobiology == ''Leonardus''' teeth are noted as being unique among meridiolestids and the animal would have had an orthal and transverse jaw-stroke with tooth-to-tooth shearing,<ref name="ReferenceA"/> though no further comments have been made on its diet.
== References == {{Reflist}}
{{Mammaliaformes|H.}} {{Taxonbar|from=Q28045585}} Category:Meridiolestida Category:Late Cretaceous mammals of South America Category:Santonian life Category:Campanian life Category:Maastrichtian life Category:Late Cretaceous genus first appearances Category:Late Cretaceous genus extinctions Category:Cretaceous Argentina Category:Fossils of Argentina Category:Los Alamitos Formation Category:Fossil taxa described in 1990 Category:Prehistoric mammal genera