Leonardus
{{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
~{{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.[https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=204742 Leonardus] at Fossilworks.org It is a meridiolestidan, closely related to the also Late Cretaceous Cronopio and the Miocene Necrolestes.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.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.
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.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 Within Meridiolestida, it consistently groups with Necrolestes and Cronopio.
Paleobiology
References
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{{Mammaliaformes|H.}}
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Category:Late Cretaceous mammals of South America
Category:Late Cretaceous genus first appearances
Category:Late Cretaceous genus extinctions
Category:Los Alamitos Formation