Proalbionbaatar is a small mammal

Mammal

Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...

 from the Upper Jurassic

Jurassic

The Jurassic is a geologic period and system that extends from about Mya to  Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...

 of Guimarota

Guimarota

Guimarota is a disused coal mine that contains a diverse array of fossil animals and plants from the Upper Jurassic, Kimmeridgian period. It is located in central Portugal, near the city of Leiria....

, Portugal

Portugal

Portugal , officially the Portuguese Republic is a country situated in southwestern Europe on the Iberian Peninsula. Portugal is the westernmost country of Europe, and is bordered by the Atlantic Ocean to the West and South and by Spain to the North and East. The Atlantic archipelagos of the...

. It's the most derived member of the order Multituberculata

Multituberculata

The Multituberculata were a group of rodent-like mammals that existed for approximately one hundred and twenty million years—the longest fossil history of any mammal lineage—but were eventually outcompeted by rodents, becoming extinct during the early Oligocene. At least 200 species are...

 known from that locality, and shared the world with the much larger dinosaur

Dinosaur

Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...

s. It lies within the suborder "Plagiaulacida

Plagiaulacida

Plagiaulacida is a group of extinct multituberculate mammals. Multituberculates were among the most common mammals of the Mesozoic, "the age of the dinosaurs"...

" and family Albionbaataridae

Albionbaataridae

Albionbaataridae is a family of small, extinct mammals within the order Multituberculata. Fossil remains are known from the Upper Jurassic and Lower Cretaceous of Europe and Asia. These herbivores lived their obscure lives during the Mesozoic, also known as the "age of the dinosaurs." They were...

.

The genus Proalbionbaatar was named by Hahn G. and Hahn R. in 1998, based on a single species. The name refers to it being both earlier and more basal than Albionbaatar

Albionbaatar

Albionbaatar is an extinct mammal from the Lower Cretaceous of England. It was a member of the also extinct order Multituberculata and shared the world with the much larger dinosaurs. It is in the suborder "Plagiaulacida", family Albionbaataridae. The genus Albionbaatar was named by...

, a broadly similar form known from the Lower Cretaceous

Cretaceous

The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...

 of Dorset

Dorset

Dorset , is a county in South West England on the English Channel coast. The county town is Dorchester which is situated in the south. The Hampshire towns of Bournemouth and Christchurch joined the county with the reorganisation of local government in 1974...

, England.

The species Proalbionbaatar plagiocyrtus was named by Hahn G. and Hahn R. in 1998. Fossil

Fossil

Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...

 remains are known from the Kimmeridgian

Kimmeridgian

In the geologic timescale, the Kimmeridgian is an age or stage in the Late or Upper Jurassic epoch or series. It spans the time between 155.7 ± 4 Ma and 150.8 ± 4 Ma . The Kimmeridgian follows the Oxfordian and precedes the Tithonian....

 (Upper Jurassic)-age strata

Stratum

In geology and related fields, a stratum is a layer of sedimentary rock or soil with internally consistent characteristics that distinguish it from other layers...

 of Guimarota, Portugal. Remains are presently restricted to two isolated upper molars, which are smaller than the corresponding teeth of paulchoffatiids (Paulchoffatiidae

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 earliest Cretaceous. Some undescribed fossils from the Middle Jurassic of England may represent earlier versions. Remains have been reported from...

is the best represented multi group from Guimarota). These teeth also have more cusps, which are arranged in two rows. (Hahn & Hahn 2000, p. 106).