''Pseudobolodon'' was a relatively early member of the also

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

order of

mammal Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...

s, Multituberculata. It lived in

Portugal Portugal, officially the Portuguese Republic ( pt, República Portuguesa, links=yes ), is a country whose mainland is located on the Iberian Peninsula of Southwestern Europe, and whose territory also includes the Atlantic archipelagos of ...

during 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 ...

, part of the "age of the

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." It lies within the

suborder Order ( la, ordo) is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and ...

" Plagiaulacida" and family

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

. The genus ''Pseudobolodon'' ("false Bolodon") was named by Hahn G. in 1977 based on two species. A third one-time species, ''P. robustus'' (Hahn, 1978), seems to have transformed into ''

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, family ...

robustus'' (Hahn G. 1978). The species ''Pseudobolodon krebsi'' was named by Hahn G. & Hahn R. in 1994.

Fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

remains consisting of two upper jaws have been found in the Kimmeridgian (Upper Jurassic)-age

strata In geology and related fields, a stratum ( : strata) is a layer of rock or sediment characterized by certain lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by visible surfaces known as ei ...

of Guimarota, Portugal. As for the septomaxilla mentioned in the title of the reference: "A small, triangular bone is placed between the premaxilla and the maxilla; this bone is interpreted as a septomaxilla. This is a bone that is typical for lower tetrapods (

amphibians Amphibians are four-limbed and ectothermic vertebrates of the class Amphibia. All living amphibians belong to the group Lissamphibia. They inhabit a wide variety of habitats, with most species living within terrestrial, fossorial, arbore ...

reptiles Reptiles, as most commonly defined are the animals in the Class (biology), class Reptilia ( ), a paraphyletic grouping comprising all sauropsid, sauropsids except birds. Living reptiles comprise turtles, crocodilians, Squamata, squamates (lizar ...

), but is usually absent in mammals", (Hahn & Hahn 2000, p. 98). The premaxilla is the front bit of your upper jaw, while the maxilla is the side of it. Like other existing mammals, humans don't have this septomaxilla. The species ''Pseudobolodon oreas'' was named by Hahn G. in 1977. Remains consisting of seven upper jaws have been found in Kimmeridgian (Upper Jurassic)-age strata of Guimarota, Portugal.

References

* 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, J.H. (2001), "Phylogeny and Systematics of multituberculate mammals", ''Paleontology'' 44, p. 389-429. * Hahn & Hahn (1994), Nachweis des Septomaxillare bei ''Pseudobolodon krebsi'' n.sp. (Multituberculata) aus dem Malm Portugals, p. 9-29, in ''Miscellanea Palaeontologica'' 3. - 531 p., 67 pl., Berl. Geowiss. Abh. Vol 13, editors Kohring R & Martin T. ''(Evidence of the septomaxilla in Pseudobolodon krebsi n.sp. ( Multituberculata) from the Malm of Portugal.)'' * Much of this information has been derived fro

Multituberculata Cope, 1884. Multituberculates Late Jurassic mammals Fossils of Portugal Prehistoric mammal genera {{Jurassic-mammal-stub