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.
The Lakota Formation is a sequence of rocks of early Cretaceous age from Western North America. Located in South Dakota, the name of the formation is derived from the Lakota Native American tribe.
Paracryptodira is an extinct group of reptiles in the clade Testudinata, known from the Jurassic to Paleogene of North America and Europe. Initially treated as a suborder sister to Cryptodira, they were then thought to be a very primitive lineage inside the Cryptodira according to the most common use of the latter taxon. They are now often regarded as late-diverging stem-turtles, lying outside the clade formed by Cryptodira and Pleurodira. The paracryptodires are said to have phylogenic relationships, noted as primary subclades, within the Baenidae and Pleurosternidae. Within each subclade, lies many biodiverse turtles that are continuously being investigated and added to the fossil record. Paracryptodires are divided into three main groups, Compsemydidae, known from the Late Jurassic to Paleocene of North America and Europe, Pleurosternidae, known from the Late Jurassic to Early Cretaceous of North America and Europe, and Baenidae, known from the Early Cretaceous to Eocene of North America. The latter two groups are more closely related to each other than to Compsemys, forming the clade Baenoidea.
Glyptops is an extinct genus of pleurosternid freshwater turtle known from the Late Jurassic of North America.
Dorsetochelys is an extinct genus of turtle from the Early Cretaceous of southern England and northwestern Germany.
Uluops is an extinct genus of paracryptodire turtle from the Late Jurassic (Tithonian) of North America. The type and only species is Uluops uluops, which is known from a single skull from the Morrison Formation.
The Villar del Arzobispo Formation is a Late Jurassic to possibly Early Cretaceous geologic formation in eastern Spain. It is equivalent in age to the Lourinhã Formation of Portugal. It was originally thought to date from the Late Tithonian-Middle Berriasian, but more recent work suggests a Kimmeridigan-Late Tithonian, possibly dating to the Early Berriasian in some areas. The Villar del Arzobispo Formation's age in the area of Riodeva in Spain has been dated based on stratigraphic correlations as middle-upper Tithonian, approximately 145-141 million years old. In the area of Galve, the formation potentially dates into the earliest Cretaceous.
Compsemys is an extinct genus of prehistoric turtles from the Late Cretaceous and Paleocene of North America and possibly Europe. The type species C. victa, first described by Joseph Leidy from the Hell Creek Formation in Montana in 1856, and another probable species C. russelli, described in 2012, from Paleocene deposits in France. Its affinites have long been uncertain, but it has recently been considered to be the most basal member of Paracryptodira, despite the clade first appearing in the Late Jurassic, and is sometimes included in its own family, Compsemydidae. A revision in 2020 found Compsemydidae to be more expansive, also containing Riodevemys and Selenemys from the Late Jurassic of Europe, and Peltochelys from the Early Cretaceous of Europe.
Pleurosternon is an extinct genus of freshwater pleurosternid turtle from the latest Jurassic to earliest Cretaceous of Europe. Its type species, P. bullockii 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.
Selenemys is an extinct genus of pleurosternid turtle from the Late Jurassic of Central West of Portugal. It is known from several specimens recovered from the Lusitanian Basin, dating to the upper Kimmeridgian age. It was one of the earliest European pleurosternids, more closely related to the later Cretaceous pleurosternids of Europe than the contemporary pleurosternids of North America. This genus was named by Adán Pérez-García and Francisco Ortega in 2011, and the type species is Selenemys lusitanica.
Baenidae is an extinct family of paracryptodiran turtles known from the Early Cretaceous to Eocene of North America. While during the Early Cretaceous they are found across North America, during the Late Cretaceous they are only found in Laramidia, having disappeared from Appalachia. The majority of lineages survived the K-Pg Extinction, but the family was extinct by the latest Eocene. The name of the type genus, Baena, appears to be of Native American origin. They are primarily found in freshwater deposits, and are considered to be aquatic, with a largely generalist habit.
The Lulworth Formation is a geologic formation in England. It dates from the late Tithonian to the mid Berriasian. It is a subunit of the Purbeck Group. In Dorset, it consists of three members, which are in ascending order, the Mupe Member, the Ridgway Member, and the Warbarrow Tout Member. The Mupe Member is typically 11 to 16 m thick and largely consists of marls and micrites with interbeds of calcareous mudstone. The Ridgeway Member is about 3 to 7 m thick and consists of in its western portion carbonaceous muds, marls and micrites, in the east the muds are replaced by micritic limestone. The Warbarrow Tout Member is 17 to 39 m thick and consists of limestone at the base and micrite and mudstone for the rest of the sequence, this member is the primary source of the vertebrate fossils within the formation. Elsewhere the unit is undifferentiated.
Kallokibotion is an extinct genus of stem-turtle from the Upper Cretaceous, known from fossils found in Romania. One species is known, Kallokibotion bajazidi, which was named by Franz Nopcsa after his lover Bajazid Doda. It literally means 'beautiful box of Bajazid'; Nopcsa chose the name because, in the words of British palaeontologist Gareth Dyke, "the shape of the shell reminded him of Bajazid's arse". A second undescribed species is known from the Santonian of Hungary.
Pleurosternidae is an extinct family of freshwater turtles belonging to Paracryptodira. They are definitively known from the Late Jurassic to Early Cretaceous (Albian) of Western Europe and North America.
The Helochelydridae are an extinct family of stem-turtles known from fossils found in North America and Europe spanning the Early to Late Cretaceous.
Helochelydra is an extinct genus of extinct stem turtle known from the Early Cretaceous (Barremian) of the Isle of Wight, southern England.
Perichelydia is a clade within Pantestudines known from the Middle Jurassic to Holocene. Alongside crown group Testudines, it also contains Helochelydridae, which is known from the Cretaceous of Europe and North America, Sichuanchelyidae from the Middle Jurassic to Paleocene of Asia and Europe, Meiolaniformes, which is known from the Cretaceous to Holocene of South America, Australia and Oceania, and Spoochelys, known from the Mid-Cretaceous Griman Creek Formation of Australia. Kallokibotion from the Late Cretaceous of Europe is also considered part of this group. Several other groups, including the proposed clade Angolachelonia, Paracryptodira, Macrobaenidae, Sinemydidae and Xinjiangchelyidae, which are sometimes considered members of Cryptodira, have also been found outside crown Testudines in several analyses. These groups are usually considered to be closer to the crown group than the other members of Perichelydia.
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.
Thalassochelydia is a clade of extinct marine turtles from the Late Jurassic and earliest Cretaceous of Europe and South America. The group is defined as including Eurysternum, Plesiochelys and Thalassemys to the exclusion of Pelomedusa, Testudo and Protostega. While a clade uniting the families Eurysternidae, Plesiochelyidae and Thalassemydidae had been supported by phylogenetic evidence, a name was not given for the clade until 2017, when Jérémy Anquetin and colleagues coined Thalassochelydia.
Necrotauliidae is an extinct family Mesozoic Amphiesmenoptera. While previously considered a paraphyletic grouping of "basal Trichoptera, basal Lepidoptera, and advanced stem-Amphiesmenoptera", they have recently been considered early diverging caddisflies. Other authors have considered them to be basal amphiesiopterans.
