| Nichollsemys Temporal range: Late Cretaceous | |
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| Skull, Royal Tyrrell Museum in Alberta, Canada | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Order: | Testudines |
| Suborder: | Cryptodira |
| Superfamily: | Chelonioidea |
| Genus: | † Nichollsemys Brinkman, 2006 [1] |
| Species | |
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Nichollsemys is a genus of extinct sea turtles. The only known species is Nichollsemys baieri. [2]
Fossils of the Nichollsemys from Alberta [Alberta]], Canada, have been described by Donald Brinkman. [3] The fossils found are all skulls.
The name of Nichollsemys is a tribute to Elizabeth Nicholls, a paleontologist from Canada who studied marine reptiles from the Triassic period. She had previously done work with Brinkman when they found the ichthyosaur genus Parvinatator. [4]
| Panchelonioidea |
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The full length of the Nichollsemys is unknown, but Brinkman made a chart of the length of some parts of the specimen. The length from the basioccipital to the premaxilla measures 11.4 cm, the width of all the quadrates measures 9.8 cm, the depth at level of the quadrates measures 7.1 cm, the intraorbital width measures 2 cm, and the length measures 3.6 cm. [5] The cranium has many things in common with that of Toxochelys: for example, they both have a rostrum basisphenoidale shaped like a rod.
The Percopsiformes are a small order of freshwater teleost fishes measuring less than 20 cm in length, comprising the trout-perch and its allies. It contains just ten extant species, grouped into seven genera and three families. Five of these genera are monotypic.
Pachyrhinosaurus is an extinct genus of centrosaurine ceratopsid dinosaur from the Late Cretaceous period of North America. The first examples were discovered by Charles M. Sternberg in Alberta, Canada, in 1946, and named in 1950. Over a dozen partial skulls and a large assortment of other fossils from various species have been found in Alberta and Alaska. A great number were not available for study until the 1980s, resulting in a relatively recent increase of interest in Pachyrhinosaurus.
Mosasaurus is the type genus of the mosasaurs, an extinct group of aquatic squamate reptiles. It lived from about 82 to 66 million years ago during the Campanian and Maastrichtian stages of the Late Cretaceous. The genus was one of the first Mesozoic marine reptiles known to science—the first fossils of Mosasaurus were found as skulls in a chalk quarry near the Dutch city of Maastricht in the late 18th century, and were initially thought to be crocodiles or whales. One skull discovered around 1780 was famously nicknamed the "great animal of Maastricht". In 1808, naturalist Georges Cuvier concluded that it belonged to a giant marine lizard with similarities to monitor lizards but otherwise unlike any known living animal. This concept was revolutionary at the time and helped support the then-developing ideas of extinction. Cuvier did not designate a scientific name for the animal; this was done by William Daniel Conybeare in 1822 when he named it Mosasaurus in reference to its origin in fossil deposits near the Meuse River. The exact affinities of Mosasaurus as a squamate remain controversial, and scientists continue to debate whether its closest living relatives are monitor lizards or snakes.
Tylosaurus is a genus of russellosaurine mosasaur that lived about 92 to 66 million years ago during the Turonian to Maastrichtian stages of the Late Cretaceous. Its fossils have been found primarily around North Atlantic Ocean including in North America, Europe, and Africa.
Anchiceratops is an extinct genus of chasmosaurine ceratopsid dinosaur that lived approximately 72 to 71 million years ago during the latter part of the Cretaceous Period in what is now Alberta, Canada. Anchiceratops was a medium-sized, heavily built, ground-dwelling, quadrupedal herbivore that could grow up to an estimated 4.3 metres (14 ft) long. Its skull featured two long brow horns and a short horn on the nose. The skull frill was elongated and rectangular, its edges adorned by coarse triangular projections. About a dozen skulls of the genus have been found.
The Horseshoe Canyon Formation is a stratigraphic unit of the Western Canada Sedimentary Basin in southwestern Alberta. It takes its name from Horseshoe Canyon, an area of badlands near Drumheller.
Stupendemys is an extinct genus of freshwater side-necked turtle, belonging to the family Podocnemididae. It is the largest freshwater turtle known to have existed, with a carapace over 2 meters long. Its fossils have been found in northern South America, in rocks dating from the Middle Miocene to the very start of the Pliocene, about 13 to 5 million years ago. Male specimens are known to have possessed bony horns growing from the front edges of the shell and the discovery of the fossil of a young adult shows that the carapace of these turtles flattens with age. A fossil skull described in 2021 indicates that Stupendemys was a generalist feeder.
Protostega is an extinct genus of sea turtle containing a single species, Protostega gigas. Its fossil remains have been found in the Smoky Hill Chalk formation of western Kansas, time-equivalent beds of the Mooreville Chalk Formation of Alabama and Campanian beds of the Rybushka Formation. Fossil specimens of this species were first collected in 1871, and named by Edward Drinker Cope in 1872. With a total length of 3.9 metres (13 ft), it is the second-largest sea turtle that ever lived, second only to the giant Archelon, and one of the three largest turtle of all time along Archelon and Gigantatypus.
Prognathodon is an extinct genus of marine lizard belonging to the mosasaur family. It is classified as part of the Mosasaurinae subfamily, alongside genera like Mosasaurus and Clidastes. Prognathodon has been recovered from deposits ranging in age from the Campanian to the Maastrichtian in the Middle East, Europe, New Zealand, and North America.
Plesiopleurodon is an extinct genus of Mesozoic marine reptiles, belonging to the Sauropterygia, known from the Late Cretaceous of North America. It was named by Kenneth Carpenter based on a complete skull with a mandible, cervical vertebra, and a coracoid. In naming the specimen, Carpenter noted "Of all known pliosauroids, Plesiopleurodon wellesi most closely resembles Liopleurodon ferox from the Oxfordian of Europe, hence the generic reference." It was initially described as a pliosauroid due to it short neck, a common trait of the superfamily. However, later exploration into the relationships of both groups indicate that not all pliosauroids have short necks and not all plesiosauroids have long necks. Later research indicates it is a member of the Polycotylidae, within the clade Occultonectia.
Eotriceratops is a genus of herbivorous ceratopsian dinosaurs which lived in the area of North America during the late Cretaceous period. The only named species is Eotriceratops xerinsularis.
Leptopleuron is an extinct genus of procolophonid that lived in the dry lands during the late Triassic in Elgin of northern Scotland and was the first to be included in the clade of Procolophonidae. First described by English paleontologist and biologist Sir Richard Owen, Leptopleuron is derived from two Greek bases, leptos for "slender" and pleuron for "rib," describing it as having slender ribs. The fossil is also known by a second name, Telerpeton, which is derived from the Greek bases tele for "far off" and herpeton for "reptile." In Scotland, Leptopleuron was found specifically in the Lossiemouth Sandstone Formation. The yellow sandstone it was located in was poorly lithified with wind coming from the southwest. The environment is also described to consist of barchan dunes due to the winds, ranging up to 20 m tall that spread during dry phases into flood plains. Procolophonoids such as Leptopleuron were considered an essential addition to the terrestrial ecosystem during the Triassic.
Gilchristosuchus is an extinct genus of neosuchian crocodyliform. Its fossils have been found in the upper Milk River Formation of Alberta, Canada, in rocks of either latest Santonian or earliest Campanian age. Gilchristosuchus was described in 1993 by Wu and Brinkman. The type species is G. palatinus, in reference to its distinctive palatine bones.
Parvinatator, from Latin, “parvus” little and “natator” swimmer, is an extinct genus of small ichthyopterygian marine reptile that lived during the Early to Middle Triassic. Its fossils have been found in British Columbia, Canada.
The Hilda mega-bonebed is a complex of fourteen probable Centrosaurus apertus bonebeds discovered near the town of Hilda in Alberta, Canada. It was first described in the scientific literature by David Eberth, Donald Brinkman, and Vaia Barkas in 2010 after more than ten years of research. The Hilda mega-bonebed is significant because the behavior of the preserved dinosaurs themselves was the dominant cause of its existence, rather than the stratum's geological history like most bonebeds. It is also Canada's largest bonebed.
Khunnuchelys was a genus of trionychine turtle from the Late Cretaceous of Asia. Three species are known, K. erinhotensis, the type species, K. kizylkumensis, and K. lophorhothon. K. erinhotensis is known from the Iren Dabasu Formation in China from the late Turonian until the middle Campanian. K. kizylkumensis is known from the late Turonian Bissekty Formation of Uzbekistan. The third species, described in 2013 by Danilov et al., is known from the early to middle Campanian aged Bostobe Formation of Kazakhstan.
Basilemys is a large, terrestrial nanhsiungchelyid turtle from the Upper Cretaceous of North and Central America. Basilemys has been found in rocks dating to the Campanian and Maastrichtian subdivisions of the Late Cretaceous and is considered to be the largest terrestrial turtle of its time. In an analysis made by Sukhanov et al. on a nansiunghelyid turtle from the Upper Cretaceous of Mongolia, it was demonstrated that Asian nanhsiungchelyids gave rise to the North American nanhsiungchelyids.
Tingmiatornis is a genus of flighted and possibly diving ornithurine dinosaur from the High Arctic of Canada. The genus contains a single species, T. arctica, described in 2016, which lived during the Turonian epoch of the Cretaceous.
Anatolemys is an extinct turtle genus in the family Macrobaenidae. Two species are known, both of which lived in the Late Cretaceous. Fossils were discovered in the Yalovach Formation of Tajikistan, the Kulbikin Member and Khodzhakul and Bissekty Formations of Uzbekistan and the Bostobe Formation of Kazakhstan. With 70 cm (2.3 ft) in carapace length, Anatolemys maximus was one of the three largest macrobaenids along with Early Cretaceous Yakemys multiporcata and Paleocene Judithemys backmani.
Eurycephalosuchus is an extinct genus of orientalosuchine alligatoroid from the Late Cretaceous Jiangxi Province of China. Known from a well preserved skull and mandible alongside various postcranial remains, Eurycephalosuchus possessed a short and broad skull with a very short skulltable. Eurycephalosuchus lived with at least one other crocodilian, an indetermined member of the clade Brevirostres. The genus is monotypic, containing only the species Eurycephalosuchus gannanensis.
Cheloniidae family | ||||
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| Genera |
|  | ||
| † Allopleuron | ||||
| † Argillochelys | ||||
| Caretta | ||||
| † Carolinochelys | ||||
| Chelonia | ||||
| † Eochelone | ||||
| Eretmochelys | ||||
| † Gigantatypus | ||||
| † Glarichelys | ||||
| † Itilochelys | ||||
| Lepidochelys | ||||
| †Mexichelys | ||||
| †Miocaretta | ||||
| Natator | ||||
| † Pacifichelys | ||||
| † Syllomus | ||||
| † Tasbacka | ||||
Phylogenetic arrangement of turtles based on turtles of the world 2017 update: Annotated checklist and atlas of taxonomy, synonymy, distribution, and conservation status. †=Extinct. | ||||