Corytophanidae is a family of iguanian lizards, also called casquehead lizards or helmeted lizards, endemic to the New World. Nine species of casquehead lizards from three genera are recognized.
Edmontosaurus is a genus of hadrosaurid (duck-billed) dinosaur. It contains two known species: Edmontosaurus regalis and Edmontosaurus annectens. Fossils of E. regalis have been found in rocks of western North America that date from the late Campanian stage of the Cretaceous Period 73 million years ago, while those of E. annectens were found in the same geographic region but in rocks dated to the end of the Maastrichtian stage of the Cretaceous, 66 million years ago. Edmontosaurus was one of the last non-avian dinosaurs, and lived alongside dinosaurs like Triceratops, Tyrannosaurus, and Pachycephalosaurus shortly before the Cretaceous–Paleogene extinction event.
Pachycephalosaurus is a genus of pachycephalosaurid dinosaurs. The type species, P. wyomingensis, is the only known species. It lived during the Late Cretaceous Period of what is now North America. Remains have been excavated in Montana, South Dakota, Wyoming and Alberta. It was a herbivorous creature which is primarily known from a single skull and a few extremely thick skull roofs, at 9 inches thick. More complete fossils have been found in recent years. Pachycephalosaurus was among the last non-avian dinosaurs before the Cretaceous–Paleogene extinction event. Another dinosaur, Tylosteus of western North America, has been synonymized with Pachycephalosaurus, as have the genera Stygimoloch and Dracorex in recent studies.
Rhineuridae is a family of amphisbaenians that includes one living genus and species, Rhineura floridana, as well as many extinct species belonging to both Rhineura and several extinct genera. The living R. floridana is found only in Florida no further north than the panhandle, but extinct species ranged across North America, some occurring as far west as Oregon. The family has a fossil record stretching back 60 million years to the Paleocene and was most diverse in the continental interior during the Eocene and Oligocene.
Edmontosaurus annectens is a species of flat-headed and duck-billed (hadrosaurid) dinosaur from the very end of the Cretaceous Period, in what is now North America. Remains of E. annectens have been preserved in the Frenchman, Hell Creek, and Lance Formations. All of these formations are dated to the late Maastrichtian stage of the Late Cretaceous Period, representing the last three million years before the extinction of the dinosaurs. Also, E. annectens is also from the Laramie Formation, and magnetostratigraphy suggests an age of 69-68 Ma for the Laramie Formation. Edmontosaurus annectens is known from numerous specimens, including at least twenty partial to complete skulls, discovered in the U.S. states of Montana, South Dakota, North Dakota, Wyoming and Colorado and the Canadian province of Saskatchewan. It was a large animal, up to approximately 12 metres (39 ft), potentially up to 15 m (49 ft) in length, with an extremely long and low skull. E. annectens exhibits one of the most striking examples of the "duckbill" snout common to hadrosaurs. It has a long taxonomic history, and specimens have at times been classified in the genera Diclonius, Trachodon, Hadrosaurus, Claosaurus, Thespesius, Anatosaurus and Anatotitan, before being grouped together in Edmontosaurus.
The smooth helmeted iguana, sometimes also known as helmeted iguana, helmeted basilisk, elegant helmeted lizard, etc., is a species of New World lizard in the family Corytophanidae.
Brachyhyops is an extinct genus of entelodont artiodactyl mammal that lived during the Eocene Epoch of western North America and southeastern Asia. The first fossil remains of Brachyhyops are recorded from the late Eocene deposits of Beaver Divide in central Wyoming and discovered by paleontology crews from the Carnegie Museum of Natural History during the early 20th century. The type species, Brachyhyops wyomingensis, is based on a single skull and was named by E.H. Colbert in 1937, but was not officially described until 1938. During the latter half of the 20th century, additional specimens from North America have been recorded from Saskatchewan and as far south as Texas, indicating that Brachyhyops had a broad distribution and was well-dispersed throughout western North America.
Asiatosuchus is an extinct genus of crocodyloid crocodilians that lived in Eurasia during the Paleogene. Many Paleogene crocodilians from Europe and Asia have been attributed to Asiatosuchus since the genus was named in 1940. These species have a generalized crocodilian morphology typified by flat, triangular skulls. The feature that traditionally united these species under the genus Asiatosuchus is a broad connection or symphysis between the two halves of the lower jaw. Recent studies of the evolutionary relationships of early crocodilians along with closer examinations of the morphology of fossil specimens suggest that only the first named species of Asiatosuchus, A. grangeri from the Eocene of Mongolia, belongs in the genus. Most species are now regarded as nomina dubia or "dubious names", meaning that their type specimens lack the unique anatomical features necessary to justify their classification as distinct species. Other species such as "A." germanicus and "A." depressifrons are still considered valid species, but they do not form an evolutionary grouping with A. grangeri that would warrant them being placed together in the genus Asiatosuchus.
Saniwa is an extinct genus of varanid lizard that lived about 48 million years ago during the Eocene epoch. It is known from well-preserved fossils found in the Bridger and Green River Formations of Wyoming. The type species S. ensidens was described in 1870 as the first fossil lizard known from North America. Several other species have since been added, but their validity is uncertain. It is a close relative of Varanus, the genus that includes monitor lizards.
Bahndwivici is an extinct genus of lizard known from a nearly complete and articulated skeleton discovered in rocks of the Green River Formation of Wyoming, United States. The skeleton is very similar to that of the modern Chinese crocodile lizard, Shinisaurus.
Afairiguana avius is an extinct iguanid lizard known from a nearly complete and articulated skeleton discovered in rocks of the Early Eocene-aged Green River Formation of Wyoming, United States. As of the initial description, the skeleton represents the oldest complete iguanian from the Western Hemisphere, and is the oldest representative of the extant iguanid family of anoles, Polychrotidae.
Varanus marathonensis, the Samos dragon, is an extinct species of monitor lizard from the middle to late Miocene of Greece and Spain, known from several specimens. A specimen consisting of a partial skull and several vertebrae was named Varanus amnhophilis in 2012 and placed in its own subgenus, Varaneades, but a 2018 study found it to be a junior synonym of Varanus marathonensis. Comparisons with other species of monitor lizards put its size between 60 and 80 cm in length. The fossil was found in the Turolian-age Mytilini Formation on the island of Samos and is currently housed in the American Museum of Natural History.
Barbaturex is an extinct genus of giant herbivorous iguanian lizards from the Eocene of Myanmar. It is represented by a single species, Barbaturex morrisoni, which is known from several partial dentaries and a fused pair of frontals, two bones that form part of the top of the skull. Based on the size of these bones, Barbaturex morrisoni is estimated to have been about 1 metre (3.3 ft) from snout to vent, and possibly up to 6 feet (1.8 m) including the tail. Barbaturex morrisoni was named after The Doors frontman Jim Morrison, a play on his epithet "The Lizard King". The genus's name is a portmanteau of the Latin words Barbatus and rex, meaning "bearded king", in reference to ridges along the mandible and the lizard's large size.
Suzanniwana is an extinct genus of iguanian lizards that lived in western North America during the earliest Eocene, approximately 56 million years ago. Two species are known from the Bighorn Basin of Wyoming: the type species S. patriciana named in 2009, and the species S. revenanta named in 2013. Suzanniwana lived during the Paleocene–Eocene Thermal Maximum, a brief period of global warming that resulted in warmer and drier conditions in the Bighorn Basin. It likely stemmed from a lineage that had migrated into the basin from regions farther to the south, following a latitudinal band of constant climatic conditions that moved northward as the planet warmed. Suzanniwana shares many skeletal features with modern casquehead lizards of the family Corytophanidae and may be a stem-corytophanid. It also closely resembles Geiseltaliellus, an iguanian from the middle Eocene Messel pit in Germany.
Anolbanolis is an extinct genus of iguanian lizards that lived in the Bighorn Basin of what is now Wyoming during the earliest Eocene. The type species A. banalis was named by paleontologist Krister Smith in 2009 from a collection of isolated skull fragments found in a layer of the Willwood Formation that dates to a brief period of global warming called the Paleocene-Eocene thermal maximum (PETM) about 56 million years ago. The genus name Anolbanolis means "poor anole" from the Greek anolbos and the name Anolis, in reference to the scrappy nature of known fossil material and its close resemblance to lizards in the genus Anolis. Smith suggested that Anolbanolis may be a close relative of Anolis or Polychrus, which are common today in Central and South America but not found as far north as Wyoming, fitting with the idea that the Bighorn Basin was warmer and wetter in the Eocene than it is currently. According to Smith, the species name banalis is a reference to it being a "banal" lizard in the Willwood, being "quite abundant in the type locality," and not unusual because "the discovery of Eocene boreal fossil members of living subtropical and tropical clades is becoming commonplace." In 2011 Smith named a second species of Anolbanolis, A. geminus, which lived in the Bighorn Basin shortly after the PETM and was about 50 percent larger than A. banalis. Smith concluded on the basis of features in A. geminus that Anolbanolis is more closely related to Anolis than it is to Polychrus.
Chamaeleontiformes is a hypothesized clade of iguanian lizards defined as all taxa sharing a more recent common ancestor with Chamaeleo chamaeleon than with Hoplocercus spinosus, Polychrus marmoratus, or Iguana iguana. It was named by paleontologist Jack Conrad in 2008 to describe a clade recovered in his phylogenetic analysis that included the extinct genus Isodontosaurus, the extinct family Priscagamidae, and the living clade Acrodonta, which includes agamids and chameleons. It is a stem-based taxon and one of two major clades within Iguania, the other being Pleurodonta. Below is a cladogram from Daza et al. (2012) showing this phylogeny:
Priscagamidae is an extinct family of iguanian lizards known from the Late Cretaceous of Mongolia and China and the Eocene of India, spanning a range from 75 to 54 million years ago. It includes the genera Heterodontagama, Mimeosaurus, Phrynosomimus, Priscagama, and possibly Pleurodontagama. The first fossils of priscagamids were found in the Djadochta and Khermeen Tsav formations of Mongolia. More recently they have been found in the Cambay Formation in India, leading to the naming of Heterodontagama in 2013. Priscagamidae was originally described as a subfamily of Agamidae called Priscagaminae in 1984, but it was reclassified as a distinct family in 1989. Most phylogenetic analyses still find a close relationship between Priscagamidae and Agamidae, although a 2015 study found it to be basal to all other iguanian clades, warranting its removal from Iguania and placement in a larger clade called Iguanomorpha.
Geiseltaliellus is an extinct genus of iguanian lizards that lived in what is now western Europe during the Eocene. It belongs to the family Corytophanidae, which includes modern casquehead lizards. Many fossils are known from Germany, France, and Belgium, with the most well preserved coming from the Messel pit lagerstätte in Messel, Germany. German paleontologist Oskar Kuhn named the genus in 1944 after the Geiseltal valley where the first specimens were found, designating the type species Geiseltaliellus longicaudus. Three new species — G. louisi, G. lamandini, and G. grisolli — were named in the 1990s and 2000s on the basis of more fragmentary remains from France and Belgium, although G. louisi has since been synonymized with G. longicaudus. In 2009 the Messel pit specimens were recognized as belonging to a species distinct from that of the G. longicaudus specimens in Geiseltalt and were collectively reclassified under a new name, G. maarius.
Magnuviator is a genus of extinct iguanomorph lizard from the Late Cretaceous of Montana, US. It contains one species, M. ovimonsensis, described in 2017 by DeMar et al. from two specimens that were discovered in the Egg Mountain nesting site. Magnuviator is closest related to the Asian Saichangurvel and Temujinia, which form the group Temujiniidae. Unlike other members of the Iguanomorpha, however, Magnuviator bears a distinct articulating notch on its tibia for the ankle bones, which has traditionally been considered a characteristic of non-iguanomorph lizards. The morphology of its teeth suggests that its diet would have mainly consisted of wasps, like the modern phyrnosomatid iguanians Callisaurus and Urosaurus, although it also shows some adaptations to herbivory.
Peradectes is an extinct genus of small metatherian mammals known from the Cretaceous and Paleocene of North and South America through the Eocene of North America and parts of Europe. The first discovered fossil, P. elegans, was one of 15 Peradectes specimens described in 1921 from the Mason pocket fossil beds in Colorado.
