''Loxaulax'' is a genus of extinct

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 ...

from the Lower

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

of southern England. It was a member of the also extinct order

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 ...

, and lived alongside 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 "

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

Eobaataridae Eobaataridae is a family of fossil mammals within the order Multituberculata. Remains are known from the Lower Cretaceous of Europe and Asia. They are among the most derived representatives of the informal suborder "Plagiaulacida", and closely re ...

. The genus ''Loxaulax'' was named by Simpson G.G. in 1928 based on one species. The

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

of ''Loxulax'' is known from a single molar. It is characterised by possessing "outer cusps of lower molar shortened antero-posteriorly, subselenodont, four in number. Inner cusps three." (Simpson, 1928).

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 of the species ''Loxaulax valdensis'' consist of a tooth found in

Valanginian In the geologic timescale, the Valanginian is an age or stage of the Early or Lower Cretaceous. It spans between 137.05 ± 0.2 Ma and 132.6 ± 0.2 Ma (million years ago). The Valanginian Stage succeeds the Berriasian Stage of the Lower Cretac ...

(Lower Cretaceous)

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 ...

belong to the

Wadhurst Clay Formation The Wadhurst Clay Formation is a geological unit which forms part of the Wealden Group and the middle part of the now unofficial Hastings Beds. These geological units make up the core of the geology of the High Weald in the English counties of West ...

of the Cliff End bonebed in

Hastings Hastings ( ) is a seaside town and Borough status in the United Kingdom, borough in East Sussex on the south coast of England, east of Lewes and south east of London. The town gives its name to the Battle of Hastings, which took place to th ...

, England. More recently, "Butler and Ford reported some IoW (Isle of Wight) Wealden mammal teeth several decades ago from the

Wessex Formation The Wessex Formation is a fossil-rich England, English geological formation that dates from the Berriasian to Barremian Stage (stratigraphy), stages of the Early Cretaceous. It forms part of the Wealden Group and underlies the younger Vectis Form ...

. They identified one of the teeth as belonging to the multituberculate ''Loxaulax'' but weren't sure about the others. Other IoW Wealden mammal teeth have been found since but have yet to be written up," (with thanks to Darren Naish). Representatives from the

Isle of Wight The Isle of Wight (Help:IPA/English, /waɪt/ Help:Pronunciation respelling key, ''WYTE'') is an island off the south coast of England which, together with its surrounding uninhabited islets and Skerry, skerries, is also a ceremonial county. T ...

Museum say that sieving is underway at one fossil location. This suggests new mammal finds are not unlikely.

remains of the species ''Loxaulax herreroi'' were found in the

Barremian The Barremian is an age in the geologic timescale (or a chronostratigraphic stage) between 125.77 Ma (million years ago) and 121.4 ± 1.0 Ma (Historically, this stage was placed at 129.4 million to approximately 125 million years ago) It is a ...

-age

Camarillas Formation The Camarillas Formation is a geological formation in the Teruel Province of Aragón, Spain whose strata date back to the Early Cretaceous (Barremian stage). The sandstones, mudstones and conglomerates of the formation, that due to syn-sedimen ...

of Galve, Spain.

References

* Simpson (1928), A catalogue of the Mesozoic mammalia in the geological department of the British Museum. London: British Museum (Nat Hist). * Kielan-Jaworowska Z & Hurum JH (2001), "Phylogeny and Systematics of multituberculate mammals". ''Paleontology'' 44, p. 389-429.

External links

Mesozodic Mammals: Plagiaulacidae, Albionbaataridae, Eobaataridae & Arginbaataridae
Multituberculata Early Cretaceous mammals of Europe Barremian life Cretaceous Spain Fossils of Spain Cretaceous England Fossils of England Camarillas Formation Prehistoric mammal genera {{cretaceous-mammal-stub