- Glirodon
Taxobox
name = "Glirodon"
fossil_range =Late Jurassic
regnum =Animal ia
classis =Mammal ia
ordo =Multituberculata
familia = Affinities unclear
genus = "Glirodon"
subdivision_ranks = Species
subdivision = "G. grandis""Glirodon" is a
genus of extinctmammal from the UpperJurassic . It was a relatively early member of the also-extinct order ofMultituberculata , suborder "Plagiaulacida ". These mammals lived inNorth America during the Mesozoic, also known as the "age of thedinosaur s".The genus "Glirodon" has been described by Engelmann G.F. and Callison G. (1999) from a 'gliriform tooth'.
The
species "Glirodon grandis", also described by Engelmann and Callison, has been found in the Upper Jurassic formations ofDinosaur National Monument inUtah (USA ). Other than being a large, early American Multituberculate, (seeMultituberculata ), the nature of this beast is somewhat unclear. It's an "allodontid (two families and the genus "Glirodon")", (Kielan-Jaworowska and Hurum, 2001). It had gliriformincisor s; incisors with the "enamel reduced to a stripe on the front side." Apparently, this condition evolved several times among Multituberculates.It's based on a portion of snout. "Glirodon" retains the plesiomorphic 'plagiaulacidan' ("
Plagiaulacida ")dental formula and shares withAllodontidae the structure of the upper premolars (Pl.1 fis 2-4). It differs from the Paulchoffatiidae and Plagiaulacidae in having a single-cusped I3," (Kielan-Jaworowska & Hurum, 2001, p.401-402). I3 refers to an upper incisor and 'plsiomorphic' means 'basal'.References
* Engelmann & Callison, (1999), Glirodon grandis, "a new multituberculate mammal from the Upper Jurassic Morrison Formation". Vertebrate Paleontology of Utah, pp.161-178, in the Utah Geological Survey, (ed. Gillette DD), 8/99.
* Kielan-Jaworowska Z & Hurum JH (2001), "Phylogeny and Systematics of multituberculate mammals". Paleontology 44, p.389-429.
* Most of this information has been derived from [http://home.arcor.de/ktdykes/plagiau.htm] MESOZOIC MAMMALS; Basal Multituberculata, an Internet directory.
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