Cronopio is an extinct genus of small insectivorous mammal known from the early Late Cretaceous of the Río Negro region in Argentina. Its only species is Cronopio dentiacutus.[1] It belongs to the Meridiolestida, an extinct group of mammals widespread in South America during the Late Cretaceous, which are more closely related to modern marsupials and placental mammals than to monotremes.
| Cronopio dentiacutus Temporal range:
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|---|---|
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| Skull diagram. Scale bar = 5 mm | |
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Clade: | Cladotheria |
| Clade: | †Meridiolestida |
| Genus: | †Cronopio Rougier et al. 2011 |
| Species: | †C. dentiacutus
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| Binomial name | |
| †Cronopio dentiacutus Rougier et al. 2011
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Description edit
Cronopio is known from the holotype MPCA PV 454, a partial skull around 27 millimetres (1.1 in) long which is missing the skull roof, basicranium and squamosals and from the referred specimens MPCA PV 450, a partial left lower jaw with damaged teeth and MPCA PV 453, an incomplete skull with a relatively complete right lower jaw missing some teeth. All specimens were collected in La Buitrera locality, from the Candeleros Formation of the Neuquén Group, dating to the early Cenomanian stage of the early Late Cretaceous, about 99.6-96 million years ago.[1]
Paleontologist Guillermo Rougier commented on the creature's "superficial" resemblance to the fictional character Scrat in the Ice Age franchise created by Chris Wedge, saying "it just goes to show how diverse ancient mammals are, that we can just imagine some bizarre critter and later find something just like it."[2]
Etymology edit
Cronopio was first named by Guillermo W. Rougier, Sebastián Apesteguía and Leandro C. Gaetano in 2011 and the type species is C. dentiacutus. The generic name is named after the fictional characters appearing in the work of Argentinian writer Julio Cortázar.[1] The specific name is derived from Latin, meaning "sharp-toothed".[1]
Phylogeny edit
Cladogram following the analysis of Rougier, Wible, Beck and Apesteguía (2012):[3]
References edit
- ^ a b c d Guillermo W. Rougier; Sebastián Apesteguía; Leandro C. Gaetano (2011). "Highly specialized mammalian skulls from the Late Cretaceous of South America". Nature. 479 (7371): 98–102. Bibcode:2011Natur.479...98R. doi:10.1038/nature10591. PMID 22051679. S2CID 4380850, supplementary information.
- ^ "Ice Age Reality?". Calgary Sun. November 9, 2011. p. 22.
- ^ Guillermo W. Rougier; John R. Wible; Robin M. D. Beck; 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. Bibcode:2012PNAS..10920053R. doi:10.1073/pnas.1212997109. PMC 3523863. PMID 23169652.