Tinodon is an extinct genus of mammal alive 155–140.2 million years ago (Oxfordian-Berriasian) which has been found in the Morrison Formation (United States),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 (Marsh, 1879) and T. micron (Ensom & Sigogneau-Russell, 2000 ).
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.
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.
Docodonta is an order of extinct mammaliaforms that lived during the Mesozoic, from the Middle Jurassic to Early Cretaceous. They are distinguished from other early mammaliaforms by their relatively complex molar teeth, from which the order gets its name. Until recently, Docodonta were represented primarily by teeth and jaws found across former Laurasia,. However, recent discoveries in China include some exceptionally well preserved, almost complete body fossils.
Morganucodonta is an extinct order of basal Mammaliaformes, a group including crown-group mammals (Mammalia) and their close relatives. Their remains have been found in Southern Africa, Western Europe, North America, India and China. The morganucodontans were probably insectivorous and nocturnal, though like eutriconodonts some species attained large sizes and were carnivorous. Nocturnality is believed to have evolved in the earliest mammals in the Triassic as a specialisation that allowed them to exploit a safer, night-time niche, while most larger predators were likely to have been active during the day.
Trechnotheria is a group of mammals that includes the therians and some fossil mammals from the Mesozoic Era. In the Jurassic through Cretaceous periods, the group was endemic to what would be Asia and Africa.
Amphidon is an extinct genus of Late Jurassic mammal from the Morrison Formation. It is present in stratigraphic zone 5. The only species in the genus is Amphidon aequicrurius, found by Simpson in 1925.
Amblotherium is an extinct genus of Late Jurassic and Early Cretaceous mammal. The type species Amblotherium pusillum is from the Lulworth Formation of southern England, while the referred species Amblotherium gracile is from stratigraphic zones 2, 3 and 5 of the Morrison Formation of the US.
Several mammals are known from the Mesozoic of Madagascar. The Bathonian Ambondro, known from a piece of jaw with three teeth, is the earliest known mammal with molars showing the modern, tribosphenic pattern that is characteristic of marsupial and placental mammals. Interpretations of its affinities have differed; one proposal places it in a group known as Australosphenida with other Mesozoic tribosphenic mammals from the southern continents (Gondwana) as well as the monotremes, while others favor closer affinities with northern (Laurasian) tribosphenic mammals or specifically with placentals. At least five species are known from the Maastrichtian, including a yet undescribed species known from a nearly complete skeleton that may represent a completely new group of mammals. The gondwanathere Lavanify, known from two teeth, is most closely related to other gondwanatheres found in India and Argentina. Two other teeth may represent another gondwanathere or a different kind of mammal. One molar fragment is one of the few known remains of a multituberculate mammal from Gondwana and another has been interpreted as either a marsupial or a placental.
Dorsetodon is an extinct genus of mammal from the Early Cretaceous (Berriasian) Purbeck Group of Britain. It is represented by isolated lower molars.
Purbeckodon is an extinct genus of mammaliaforms, possibly belonging to Morganucodonta, that is known from Early Cretaceous deposits of southeastern Dorset, England. It was collected in the Purbeck Limestone Group of Dorset. It was first named by Percy M. Butler, Denise Sigogneau-Russell and P. C. Ensom in 2011 and the type species is Purbeckodon batei.
Aegialodontia is a clade of extinct early mammals, close to the origin of Boreosphenida. The clade includes some of the oldest known tribosphenic taxa, until the discovery of Tribactonodon from the Berriasian Durlston Formation in 2001, Aegialodon from the Valanginian Wadhurst Clay Formation was the oldest taxon with the tooth form. The Aptian to Albian taxon Kielantherium from Mongolia, formerly a synonym of Aegialodon, is also within the group, sister to Aegialodon within Aegialodontidae.
Dyskritodon is a genus of extinct mammal from the Early Cretaceous of Morocco, and possibly the Early Jurassic of India. Of uncertain affinities, it is tentatively described as a eutriconodont.
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.
Chunnelodon is a genus of extinct mammal from the Early Cretaceous of Southern England. The type and only species is Chunnelodon alopekodes, represented by two lower molars from the Sunnydown Farm locality of the Lulworth Formation of Dorset. The taxon was described by Paul Ensom and Denise Sigogneau-Russell in 1998, who gave the species name from the translation of the Ancient Greek phrase "sly as a fox", with the generic name honouring the British-French collaboration and the newly inaugurated Channel Tunnel. Chunnelodon is diagnosed by multiple features of the dental anatomy including slightly asymmetrical but aligned roots, sharp cusps, a tall protoconid and metaconid, a small paraconid, and a reduced talonid. While it was only assigned to Cladotheria indeterminate, Chunnelodon was likely closely related to Dryolestoidea, although outside the clade.
Thereuodon is a genus of extinct mammal known from the Early Cretaceous of southern England and Morocco. The type species, named by Denise Sigogneau-Russell in 1989 for teeth from the earliest Cretaceous Ksar Metlili Formation of Morocco, is Thereuodon dahmani, while the referred species named by Sigogneau-Russell and Paul Ensom for teeth from the Lulworth Formation of England is Thereuodon taraktes. The two species are separated by a break in the cingulum in T. dahmani, a more obsute medial crest in T. taraktes, a duller stylocone in T. taraktes, a "c" cuspule in T. dahmani, and a reduced facet A in T. taraktes. The genus Thereuodon is the only taxon in the symmetrodont family Thereuodontidae, which may be closely related to Spalacotheriidae. Tooth referred to T. cf. taraktes is known from the Berriasian aged Angeac-Charente bonebed of France.
Magnimus is a genus of extinct mammal from the Early Cretaceous of Southern England. The type and only species is Magnimus ensomi, described in 1999 by Denise Sigogneau-Russell for molars from the Berriasian Lulworth Formation. The specific name was given to honour Paul Ensom, a discoverer of many teeth from the Purbeck beds, while the generic name is from the Latin words for "large" and "mouse". It is similar to but distinct from Peramus and Abelodon, but its classification cannot be narrowed down beyond indeterminate Zatheria due to its incomplete nature.
Denise Sigogneau-Russell is a French palaeontologist who specialises in mammals from the Mesozoic, particularly from France and the UK. She is currently based at the Muséum National d'Histoire Naturelle.
Dobunnodon its an extinct genus of docodont from the Middle Jurassic (Bathonian) Forest Marble Formation of England, first discovered in Oxfordshire near the village of Kirtlington. The type species, D. mussettae, was originally named as a species of Borealestes in 2003.