''Guimarotodon'' is an extinct mammal of the Upper

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The J ...

. It was a relatively early member of the also extinct

order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of ...

Multituberculata Multituberculata (commonly known as multituberculates, named for the multiple tubercles of their teeth) is an extinct order of rodent-like mammals with a fossil record spanning over 130 million years. They first appeared in the Middle Jurassic, ...

. It made its living nibbling plants as great big, and small,

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

s roamed the world. (For the technically minded, suborder

Plagiaulacida Plagiaulacida is a group of extinct multituberculate mammals. Multituberculates were among the most common mammals of the Mesozoic, "the age of the dinosaurs". Plagiaulacids are a paraphyletic grouping, containing all multituberculates that lie ...

, family

Paulchoffatiidae Paulchoffatiidae is a family of extinct mammals that lived predominantly during the Upper Jurassic period, though a couple of genera are known from the Early Cretaceous. Fossils have been reported from Europe (Portugal, Spain, Germany and England ...

.) ''Guimarotodon'' ("Guimarota tooth") Hahn G, 1969. "''Guimarotodon'' Hahn 1969 exhibits a more slender Corpus mandibulae than either ''

Paulchoffatia ''Paulchoffatia'' is a genus of extinct mammal of the Upper Jurassic - Lower Cretaceous. It was a relatively early member of the also extinct order Multituberculata, within the suborder " Plagiaulacida" and family Paulchoffatiidae. It lived in ...

'' or ''

Meketibolodon ''Meketibolodon'' is a genus of extinct mammal from the Kimmeridgian (Upper Jurassic) Camadas de Guimarota of Guimarota, Portugal. It was a relatively early member of the also extinct order Multituberculata, suborder Plagiaulacida, fami ...

''. The most conspicuous character of this genus is the morphology of the P3-4 and the M1.". The Corpus mandibulae is the part of the jaw below the tooth row. P3-4 are upper

premolar The premolars, also called premolar teeth, or bicuspids, are transitional teeth located between the canine and molar teeth. In humans, there are two premolars per quadrant in the permanent set of teeth, making eight premolars total in the mouth ...

s, whilst M1 is an upper molar tooth. "The

incisor Incisors (from Latin ''incidere'', "to cut") are the front teeth present in most mammals. They are located in the premaxilla above and on the mandible below. Humans have a total of eight (two on each side, top and bottom). Opossums have 18, w ...

is relatively little curved and its root is of similar length as that of ''Meketibolodon'' and extends to underneath the posterior premolars." (Both quotations from Hahn & Hahn 2000, p. 105-106).

Guimarotodon leiriensis

''Guimarotodon leiriensis'' is found in Kimmeridgian (Upper Jurassic) of Guimarota, Portugal. Classification is based on three lower jaws. The species name refers to the local town of

Leiria Leiria (; cel-x-proto, ɸlāryo) is a city and municipality in the Central Region of Portugal. It is the 2nd largest city in that same region, with a municipality population of 128,640 (as of 2021) in an area of . It is the seat of its own distr ...

References

* Hahn (1969), Beiträge zur Fauna der Grube Guimarota Nr. 3. Die Multituberculata. Paleontographica, A, 133, p. 1-100. ''(Contributions on the fauna of the Guimarota mine no. 3. The Multituberculates.)'' * Hahn G & Hahn R (2000), Multituberculates from the Guimarota mine, p. 97-107 in Martin T & Krebs B (eds), Guimarota - A Jurassic Ecosystem, Verlag Dr Friedrich Pfeil, München. * Kielan-Jaworowska Z & Hurum JH (2001), "Phylogeny and Systematics of multituberculate mammals". ''Paleontology'' 44, p. 389-429. * Much of this information has been derived fro

MESOZOIC MAMMALS; Basal Multituberculata, an internet directory. Multituberculates Late Jurassic mammals of Europe Prehistoric mammal genera Fossil taxa described in 1969 {{jurassic-mammal-stub