Santonian dinosaurs

Alvarezsaurus (; "Don Gregorio Alvarez's lizard") is a genus of alvarezsaurid dinosaur from the Late Cretaceous, living in Argentina approximately 86 - 83 million years ago. It was a small dinosaur, measuring long and weighing approximately . It was found in the Bajo de la Carpa Formation and was named by paleontologist José Bonaparte in 1991 after the historian Don Gregorio Alvarez. The type species is A. calvoi.

Antarctosaurus (; meaning "southern lizard") is a genus of titanosaurian sauropod dinosaur from the Late Cretaceous Period of what is now South America. The type species, Antarctosaurus wichmannianus, and a second species, Antarctosaurus giganteus, were described by prolific German paleontologist Friedrich von Huene in 1929. Three additional species of Antarctosaurus have been named since then but later studies have considered them dubious or unlikely to pertain to the genus.

Aucasaurus (meaning 'Auca Mahuevo lizard') is a genus of medium-sized abelisaurid theropod dinosaur from Argentina that lived during the Late Cretaceous (Santonian to Campanian stage) of the Anacleto Formation. It was smaller than the related Carnotaurus, although more derived in some ways, such as its extremely reduced arms and almost total lack of fingers. The type skeleton is complete to the thirteenth caudal vertebra, and so is relatively well understood, and was the most complete abelisaurid known when described in 2002. However, the skull is damaged, causing some paleontologists to specu

Achillesaurus is a genus of alvarezsaurid theropod dinosaur from the Santonian-aged (Late Cretaceous) Bajo de la Carpa Formation of Rio Negro, Argentina. It contains one species, Achillesaurus manazzonei.

Yamaceratops is a genus of primitive ceratopsian that lived during the Late Cretaceous in what is now Mongolia. The genus contains a single species, Y. dorngobiensis. It was a relatively small dinosaur, with an estimated length of and weighing around .

Bonitasaura is a genus of titanosaurian dinosaur hailing from uppermost layers of the Late Cretaceous (Santonian) Bajo de la Carpa Formation, Neuquén Group of the eastern Neuquén Basin, located in Río Negro Province, Northwestern Patagonia, Argentina. The remains, consisting of a partial sub-adult skeleton jumbled in a small area of fluvial sandstone, including a lower jaw with teeth, a partial vertebrae series, and limb bones, were described by Sebastian Apesteguía in 2004.

Velocisaurus ("swift lizard") is a genus of noasaurid theropod dinosaur from the Late Cretaceous period of Argentina.

Jaxartosaurus (meaning "Jaxartes lizard" after the early name of the Syr Darya) is a genus of hadrosaurid dinosaur similar to Corythosaurus which lived during the Late Cretaceous. Its fossils were found in Kazakhstan.

Aralosaurus is a genus of hadrosaurid dinosaur that lived during the Late Cretaceous in what is now Kazakhstan. It is known only by a posterior half of a skull (devoid of its mandible) and some post-cranial bones found in the Bostobe Formation in rocks dated from the Upper Santonian - lower Campanian boundary, at about 83.6 Ma (millions of years ago). Only one species is known, Aralosaurus tuberiferus, described by Anatoly Konstantinovich Rozhdestvensky in 1968. The genus name means "Aral Sea lizard", because it was found to the northeast of the Aral Sea. The specific epithet tuberiferus means

Ajkaceratops (pronounced "oi-ka-sera-tops") is a genus of ceratopsian dinosaur described in 2010. It lived during the Late Cretaceous in the western Tethyan archipelago, in what is now Europe. The type species, A. kozmai, was originally described as a ceratopsian most closely related to forms in east Asia, from where its ancestors may have migrated by island-hopping. Later research, however, questioned this assignment and treated Ajkaceratops as an ornithischian of unresolved affinity. In 2026, more complete cranial remains referable to the species were described, supporting its placement as a

Graciliceratops (meaning "slender horned face") is a genus of neoceratopsian dinosaurs that lived in Asia during the Late Cretaceous period.

Acrotholus (Greek for "highest dome"- akros meaning highest and tholos meaning dome) is an extinct genus of pachycephalosaurian dinosaur that lived during the Santonian of the late Cretaceous, in the Milk River Formation of Canada. The type species, A. audeti, was named after Roy Audet allowing access to his ranch leading to the discovery of the species. The discovery of this specimen lead to several new revelations in the fossil records questioning the preservation of small-bodied organisms along with the evolution of early pachycephalosaurs. The iconic cranial dome found on Acrotholus makes

Rinconsaurus is a genus of titanosaur sauropod dinosaur from the Late Cretaceous in what is now Argentina. The type species, Rinconsaurus caudamirus, was described by Calvo and Riga in 2003, and is based on three partial skeletons.

Hungarosaurus (meaning 'Hungarian lizard' from the Latin Hungaria, 'Hungary', and Greek σαυρος/sauros, 'lizard') is an extinct genus of nodosaurid ankylosaurian dinosaur from the Upper Cretaceous (Santonian) Csehbánya Formation of the Bakony Mountains, western Hungary. The type (and only) species is H. tormai, and represents the most completely known ankylosaur from the Cretaceous of Europe. Hungarosaurus walked on four legs and its body was covered with hundreds of osteoderms. The length of mature specimens was about .

Arstanosaurus (meaning "Arstan lizard" after the Arstan well) is a genus of hadrosauroid dinosaur from the Late Cretaceous-aged (Santonian-Campanian) Bostobe Formation of Kazakhstan. It has had a confusing history, being considered a hadrosaurid, a ceratopsid, or both at the same time (chimeric).

Claosaurus ( ; Greek κλάω, klao meaning 'broken' and , sauros meaning 'lizard'; "broken lizard", referring to the odd position of the fossils when discovered) is a genus of hadrosauroid dinosaur that lived during the Late Cretaceous Period (Santonian-Campanian) of what is now North America. The type and only known valid species is Claosaurus agilis. Traditionally classified as an early member of the family Hadrosauridae, a 2008 analysis found Claosaurus to be outside of the clade containing Hadrosaurus and other hadrosaurids, making it the closest non-hadrosaurid relative of true hadrosaurids

Pneumatoraptor is a genus of small paravian, possibly a dromaeosaurid, dinosaur that lived in Hungary. It is known from a single complete left shoulder girdle (scapulocoracoid) found in the Csehbánya Formation of the Iharkút locality in the Bakony Mountains of western Hungary. This formation dates to the late Cretaceous period (Santonian age) about 85 million years ago.

Albinykus (meaning "Albin claw", after a term used by Mongolian shamans to describe light phenomena in the Gobi Desert) is a genus of alvarezsaurid dinosaur whose fossils have been found in the Late Cretaceous-aged (Santonian) Javkhlant Formation in the Gobi Desert of Mongolia. The type species, A. baatar, was named by Sterling J. Nesbitt, Julia A. Clarke, Alan H. Turner and Mark A. Norell in 2011.

Craspedodon (meaning 'edge tooth') is an extinct genus of ornithischian dinosaur from the Late Cretaceous Lonzée Member of Belgium. Only a single species, C. lonzeensis, is known.

thumb|250px|left|Size comparison Petrobrasaurus is a genus of herbivorous sauropod dinosaur. It is a titanosaur which lived during the upper Cretaceous period (Coniacian-Santonian age) in what is now Rincón de los Sauces, Patagonia, Argentina. It is known from the holotype MAU-Pv-PH-449 — a partial disarticulated skeleton recovered from the Plottier Formation (Neuquén Basin), Argentina. This genus was named by Leonardo S. Filippi, José Ignacio Canudo, Leonardo J. Salgado, Alberto C. Garrido, Rodolfo A. Garcia, Ignacio A. Cerda and Alejandro Otero in 2011, and the type species is Petrobrasaurus

Gryphoceratops is an extinct genus of leptoceratopsid ceratopsian dinosaur known from the Late Cretaceous of Alberta, southern Canada.

Llukalkan (Mapuche for "one who causes fear") is a genus of abelisaurid theropod dinosaur from the Late Cretaceous Bajo de la Carpa Formation of Argentina. The type species is Llukalkan aliocranianus.

Notocolossus is a genus of titanosaurian sauropod dinosaur from late Cretaceous strata of Mendoza Province, Argentina.

Tratayenia is an extinct genus of megaraptoran theropod dinosaurs known from remains found in the Late Cretaceous (Santonian age) Bajo de la Carpa Formation of Argentina. The type and only species, Tratayenia rosalesi, was described in March 2018.

Mochlodon is a genus of rhabdodontid dinosaurs from the Late Cretaceous of Austria and Hungary. It lived during the Late Cretaceous (85-80 Ma) and two species have been named, M. suessi and M. vorosi, although the latter has been regarded as a junior synonym of the ceratopsian Ajkaceratops.

Acantholipan is a genus of herbivorous nodosaurid dinosaur from Mexico from the early Santonian age of the Late Cretaceous. It includes one species, Acantholipan gonzalezi.

species of reptile (fossil)

Traukutitan is a genus of titanosaur sauropod dinosaur which lived during the late Cretaceous (Santonian age).

Muyelensaurus (meaning "Muyelen lizard", after an indigenous name for the Colorado River in Argentina) is a genus of titanosaurian sauropod dinosaur from the Late Cretaceous of Argentina. It was more slender than other titanosaurs. Fossils have been recovered in the Neuquén province of Patagonia and were originally assigned to the Portezuelo Formation but further research showed that these layers belong to the Plottier Formation. The type species is M. pecheni. The name Muyelensaurus first appeared in a 2007 paper by Argentine paleontologists Jorge Calvo of the Universidad Nacional del Comahue

Hierosaurus (meaning "sacred lizard") is an extinct genus of nodosaurid ankylosaur which lived during the Late Cretaceous 87 to 82 million years ago. Its fossils were found in the Smoky Hill Chalk Member of the Niobrara Formation, in western Kansas, which would have been near the middle of the Western Interior Sea during the Late Cretaceous. It was a nodosaurid, an ankylosaur without a clubbed tail. thumb|left|Spine The only species of this genus, Hierosaurus sternbergii, was described by George Wieland on the basis of cranial and postcranial osteoderms collected by Charles Hazelius Sternberg

Batyrosaurus is an extinct genus of herbivorous basal hadrosauroid dinosaur known from the Late Cretaceous Bostobe Formation (Santonian to Campanian stage) of central Kazakhstan. It contains a single species, Batyrosaurus rozhdestvenskyi. It is possible that Batyrosaurus represents the same taxon as the doubtful Arstanosaurus akkurganensis as both were found from the same formation.

Huehuecanauhtlus is a genus of hadrosauroid dinosaur known from the Late Cretaceous (Santonian stage) of Michoacán, western Mexico. It contains a single species, Huehuecanauhtlus tiquichensis.

Overosaurus (meaning "Overo lizard", after the Cerro Overo locality) is an extinct genus of sauropod dinosaurs, containing only a single species, Overosaurus paradasorum. This species lived approximately 86 to 84 million years ago during the latter part of the Cretaceous Period in what is now Patagonia (in southern Argentina). Overosaurus paradasorum was relatively small compared to other sauropods from Patagonia, like the saltasaurids and other aeolosaurines, estimated as approximately . It was a ground-dwelling herbivore.

Ibirania (meaning "Ibirá wanderer" or "tree wanderer") is a genus of dwarf saltasaurine titanosaur dinosaur from the Late Cretaceous (Santonian to Campanian) São José do Rio Preto Formation (Bauru Basin) of Southeast Brazil. The type species is Ibirania parva. It is one of the smallest sauropods known to date, comparable in size to the titanosaur Magyarosaurus.

Viavenator (meaning "road hunter") is a genus of carnivorous abelisaurid theropod dinosaur that lived in the Santonian-aged (Late Cretaceous) Bajo de la Carpa Formation of Argentina. Only a single species is known, V. exxoni, formally described in 2016 by Filippi and colleagues.

Kansaignathus () is an extinct genus of dromaeosaurid theropod from the Late Cretaceous Yalovach Formation (or Ialovachsk Formation) of Tajikistan. The genus contains only one species, the type species, K. sogdianus. The generic name of Kansaignathus comes from near the town of Konsoy ("Kansai" in Russian) where it was discovered and the Greek word "gnathos" meaning "jaw". The specific epithet "sogdianus" is derived from the historical region of Sogdiana, which was an ancient name for the Fergana Valley region where the fossil was discovered. Kansaignathus is known from a single right dentary

Zhanghenglong is an extinct genus of herbivorous hadrosauroid iguanodont dinosaur known from the Late Cretaceous (middle Santonian stage) Majiacun Formation in Xixia County of Henan Province, China. It contains a single species, Zhanghenglong yangchengensis, represented by a disarticulated and partial cranium and postcranial skeleton.

Inawentu (meaning "imitator") is an extinct genus of titanosaurian sauropod dinosaur from the Late Cretaceous Bajo de la Carpa Formation of Argentina. The genus contains a single species, I. oslatus, known from a partial articulated skeleton including the skull. The square-shaped jaw of Inawentu demonstrates convergent characteristics with rebbachisaurids.

Kazaklambia is an extinct genus of herbivorous lambeosaurine dinosaur known from the Late Cretaceous Dabrazinskaya Svita (Santonian stage) of southern Kazakhstan. It contains a single species, Kazaklambia convincens.

Diuqin (meaning "bird of prey") is an extinct genus of unenlagiine theropod dinosaurs from the Late Cretaceous (Santonian) Bajo de la Carpa Formation of Argentina. The genus contains a single species, Diuqin lechiguanae, known from a humerus and fragmentary vertebrae.

Microcoelus (meaning "small hollow") is a dubious genus of small titanosaurian sauropod dinosaur from the Late Cretaceous (Santonian stage) Bajo de la Carpa Formation, Argentina. It is known from only a single dorsal vertebra, although a left humerus was formerly referred to this taxon, but it is now considered to belong to Neuquensaurus. The type (and only known) species is M. patagonicus, described by British paleontologist Richard Lydekker in 1893.

Yeneen is an extinct genus of titanosaurian sauropod dinosaurs known from the Late Cretaceous (Santonian age) Bajo de la Carpa Formation of Argentina. The genus contains a single species, Yeneen houssayi, known from at least one partial skeleton. Its discovery highlights the diversity of titanosaurs in this formation, which also includes Bonitasaura, Inawentu, Overosaurus, Rinconsaurus, and Traukutitan.

Mahuidacursor (meaning "mountain runner", meaning "mountain" in Mapudungun) is a genus of basal ornithopod dinosaur from the Santonian Bajo de la Carpa Formation of the Neuquén Basin in northern Patagonia, Argentina. The type and only species is M. lipanglef.