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

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

order of

mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

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

. It lived in

Portugal Portugal, officially the Portuguese Republic, is a country on the Iberian Peninsula in Southwestern Europe. Featuring Cabo da Roca, the westernmost point in continental Europe, Portugal borders Spain to its north and east, with which it share ...

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 143.1 Mya. ...

, part of the "age of the

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

s." It lies within the

suborder Order () 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 recognized ...

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

" and 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 ...

. 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 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 preserve ...

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 (geology), rock or sediment characterized by certain Lithology, lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by v ...

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 ectothermic, anamniote, anamniotic, tetrapod, four-limbed vertebrate animals that constitute the class (biology), class Amphibia. In its broadest sense, it is a paraphyletic group encompassing all Tetrapod, tetrapods, but excl ...

reptiles Reptiles, as commonly defined, are a group of tetrapods with an ectothermic metabolism and Amniotic egg, amniotic development. Living traditional reptiles comprise four Order (biology), orders: Testudines, Crocodilia, Squamata, and Rhynchocepha ...

), 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. (

) from the Malm of Portugal.)'' * Much of this information has been derived fro

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