In the geological timescale, the Tithonian is the latest age of the Late Jurassic Epoch and the uppermost stage of the Upper Jurassic Series. It spans the time between 149.2 ±0.7 Ma and 145.0 ± 4 Ma. It is preceded by the Kimmeridgian and followed by the Berriasian.
The Pleurodira are one of the two living suborders of turtles, the other being the Cryptodira. The division between these two suborders represents a very deep evolutionary divide between two very different types of turtles. The physical differences between them, although anatomical and largely internal, are nonetheless significant, and the zoogeographic implications of them are substantial. The Pleurodira are known more commonly as the side-necked turtles and the name Pleurodira quite literally translates to side neck, whereas the Cryptodira are known as hidden-necked turtles. The Pleurodira turtles are currently restricted to freshwater habitats in the Southern Hemisphere, largely to Australia, South America, and Africa. Within the Pleurodira, three living families are represented: Chelidae, also known as the Austro-South American side-necked turtles, the Pelomedusidae, also known as the African mud terrapins, and the Podocnemididae, also known as the American side-neck river turtles. However, they were cosmopolitan clade during the Cretaceous and most of the Cenozoic, and even occurred in marine environments around the world.
Osmylidae are a small family of winged insects of the net-winged insect order Neuroptera. The osmylids, also called lance lacewings, stream lacewings or giant lacewings, are found all over the world except North and Central America. There are around 225 extant species.
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. 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.
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.
Denazinemys was a genus of baenid turtle that lived in the Late Cretaceous of New Mexico. The holotype specimen, which D. nodosa was based on, USNM 8345, consists of a partial carapace and plastron. It came from the De-na-zin Member of the Kirtland Formation, and therefore, Denazinemys lived in the Kirtlandian land-vertebrate age. Many specimens other than the holotype have been assigned to Denazinemys.
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. Turtles similar to Kallokibotion were reported from the Paleocene of France and the Lower Maastrichtian of Volgograd Oblast, Russia, but these similarities were dismissed later.
Sichuanchelyidae is a family of extinct turtles in the clade Testudinata. It includes all perichelydians that are more closely related to Sichuanchelys than Meiolania, Helochelydra, or any extant turtles.
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.
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.
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.
Riodevemys is an extinct genus of pleurosternid turtle that inhabited Spain during the Late Jurassic epoch. It is known from a single species, R. inumbragigas.
