Plagiaulacida is a group of extinct multituberculate mammals. Multituberculates were among the most common mammals of the Mesozoic, "the age of the dinosaurs". Plagiaulacids, an informal suborder, are the most basal of this order, and ranged from the Middle Jurassic Period to the Lower Cretaceous Period of the northern hemisphere.
Sunnyodon is a genus of tiny, extinct mammal, probably of the Lower Cretaceous. Found in what is now southern England and Denmark, it was a relatively early member of the extinct order of Multituberculata. It is part of the suborder Plagiaulacida and family Paulchoffatiidae.
Gerhardodon is an extinct genus of mammal from the Lower Cretaceous of southern England. It was a member of the also extinct order of Multituberculata, and lived with such dinosaurs as Iguanodon. It lies within the suborder "Plagiaulacida" and family Pinheirodontidae.
Bolodon is a genus of extinct mammal from the Lower Cretaceous of Europe and North America. It was a member of the extinct order of Multituberculata and belongs to the suborder Plagiaulacida and family Plagiaulacidae.
Albionbaatar is an extinct mammal from the Lower Cretaceous Lulworth Formation 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 Kielan-Jaworowska Z. and Ensom P.C. in 1994 based on a single species.
Echinodon is a genus of heterodontosaurid dinosaur that lived during the earliest Cretaceous of southern England and possibly western France in the Berriasian epoch. The first specimens were jaw bones named Echinodon becklesii by Sir Richard Owen in 1861, and since their original description only additional teeth have been discovered. The specific name honours collector Samuel Beckles who discovered the material of Echinodon and many other taxa from across England, while the genus name translates as "prickly tooth" in reference to the dental anatomy of the taxon.
Goniopholis is an extinct genus of goniopholidid crocodyliform that lived in Europe and Africa during the Late Jurassic and Early Cretaceous. Being semi-aquatic it is very similar to modern crocodiles. It ranged from 2–4 metres in length, and would have had a very similar lifestyle to the American alligator or Nile crocodile.
Tinodon is an extinct genus of mammal alive 155-140.2 million years ago (Oxfordian-Berriasian) which has been found in the Morrison Formation, the Alcobaça Formation (Portugal) and the Lulworth Formation (England). It is of uncertain affinities, being most recently recovered as closer to therians than eutriconodonts but less so than allotherians. Two species are known: T. bellus and T. micron.
Nannosuchus is an extinct genus of goniopholidid mesoeucrocodylian from the Berriasian Middle Purbeck Formation of England that was originally named as a species of Goniopholis. The type species, N. gracilidens, is based on the holotype BMNH 48217, scattered fragmentary remains that include parts of the skull and various other postcranial elements named in 1879.
Pleurosternon is an extinct genus of freshwater pleurosternid turtle from the late Jurassic period to the early Cretaceous period of Europe. Its type species, P. bullocki was described by the paleontologist Richard Owen in 1853. Since then, and throughout the late 19th century, many fossil turtles were incorrectly assigned to this genus, though only two are currently considered valid.
Triconodon is a genus of extinct mammal from the Early Cretaceous of England and France with two known species: T. mordax and T. averianovi. First described in 1859 by Richard Owen, it is the type genus for the order Triconodonta, a group of mammals characterised by their three-cusped (triconodont) molar teeth. Since then, this "simplistic" type of dentition has been understood to be either ancestral for mammals or else to have evolved multiple times, rendering "triconodonts" a paraphyletic or polyphyletic assemblage respectively, but several lineages of "triconodont" mammals do form a natural, monophyletic group, known as Eutriconodonta, of which Triconodon is indeed part of.
Peramus is an extinct genus of cladotherian mammal. It lived in the Late Jurassic and Early Cretaceous of Europe and North Africa.
Hylaeochelys is an extinct genus of plesiochelyid turtle that lived during the Late Jurassic-Early Cretaceous in Portugal, Spain, France, and southern England. The type species was originally named by Richard Owen as Pleurosternon latiscutatum in 1853, before being moved to the new genus Hylaeochelys by Richard Lydekker in 1889. Other species included in the genus are H. belli, H. kappa and H. lata, originally named under different genera by Gideon Mantell and Owen, respectively. All species are represented by carapaces, primarily from the Lulworth Formation of the Purbeck Limestone Group that was deposited during the Berriasian.
Achyrodon is an extinct genus of mammal from the Berriasian epoch of Early Cretaceous southern England. The taxon was first described by Richard Owen in 1871 for teeth from the Lulworth Formation. The taxon has been considered a synonym of co-existing Amblotherium pusillum, but can be distinguished by differences in the dental anatomy and an overall smaller size. Achyrodon was closely related to co-existing genus Phascolestes and the slightly younger European form Crusafontia, and together they make up the subfamily Kurtodontinae within Dryolestidae, a family of early mammals between modern monotremes and therians with no living descendants.
Phascolestes is a genus of extinct mammal from the Berriasian epoch of Early Cretaceous Southern England. The type and only species is Phascolestes mustelulus, which was named by Richard Owen in 1871 for dental material from the Lulworth Formation. Phascolestes is a close relative of co-existing taxon Achyrodon within the subfamily Kurtodontinae of the family Dryolestidae, with Kurtodon being a junior synonym of Phascolestes although the subfamily name is still applicable.
Spalacotherium is a genus of extinct mammal from the Early Cretaceous of Europe. The type species Spalacotherium tricuspidens was originally named by Richard Owen in 1854, and its material includes maxillary and dentary fragments and many teeth from the Berriasian Lulworth Formation of southern England. Referred species include S. taylori, S. evansae and S. hookeri also from the Lulworth deposits, and S. henkeli from Barremian deposits of Galve, Spain. The Lulworth taxon Peralestes longirostris, named by Owen in 1871, is a junior synonym of the type species S. tricuspidens. Spalacotherium is the namesake taxon of the family Spalacotheriidae, which is an extinct clade within Trechnotheria that may be closely related to the Gondwanan clade Meridiolestida, or united with the family Zhangheotheriidae to form Symmetrodonta.S. evansae is also from the Berriasian aged Angeac-Charente bonebed in western France.
Peramuroides is a genus of extinct mammal from the Early Cretaceous of southern England. The type and only species is Peramuroides tenuiscus, described in 2012 by Brian Davis for dentary fragments and teeth from the Berriasian Lulworth Formation. The genus name references closely related Peramus, while the species name is based on the Latin word for "thin". Peramuroides is closely related to coexisting genera Peramus and Kouriogenys, and along with other genera these make up the family Peramuridae, a group of extinct zatherians.
Durlstodon is a genus of extinct mammal from the Early Cretaceous of Southern England. It contains a single species, Durlstodon ensomi, which is known from molars found in the Berriasian Lulworth Formation of Durlston Bay, Dorset, after which the genus was named. The species name honours Paul Ensom, discoverer of many fossil mammals from Lulworth. Durlstodon and two of its contemporaries, Tribactonodon and Durlstotherium, had tribosphenidan (three-cusped) molars, which are an advanced characteristic among eutherian mammals and suggest that the group emerged earlier than the Early Cretaceous.
Parasaurillus is a genus of extinct lizard from the Early Cretaceous of southern England. The type and only species is Parasaurillus pseudobtusus, named in 2002 by Susan E. Evans and Belinda Searle for extensive jaw and tooth material that has previously been classified as either Saurillus obtusus or Pseudosaurillus from the Berriasian Lulworth Formation. The taxon was found in the Mammal Bed near the base of the formation alongside the other lizards Becklesius, Dorsetisaurus, Durotrigia, Paramacellodus, Pseudosaurillus, Parviraptor and Saurillus obtusus. It is likely closely related to Scincoidea, more so than other contemporary taxa.
Pseudosaurillus is a genus of extinct lizard from the Early Cretaceous of southern England. The type and only species is Pseudosaurillus becklesi, named in 1967 by R. Hoffstetter limited jaw and tooth material from the Berriasian Lulworth Formation. A large amount of material that was additionally referred to Saurillus by Hoffstetter was reassigned to Pseudosaurillus in 1983 by Estes, but this has since been reclassified within its own genus Parasaurillus by Susan E. Evans and Belinda Searle in 2002. The taxon was found in the Mammal Bed near the base of the formation alongside the other lizards Becklesius, Dorsetisaurus, Durotrigia, Paramacellodus, Parasaurillus, Parviraptor and Saurillus. Like Becklesius, Pseudosaurillus may be a member of the family Paramacellodidae.
