Cretaceous dinosaurs

Spinosauridae (or spinosaurids) is a clade or family of tetanuran theropod dinosaurs comprising ten to seventeen known genera. Spinosaurid fossils have been recovered worldwide, including Africa, Europe, South America, and Asia. Their remains have generally been attributed to the Early to Late Cretaceous.

Abelisauridae (meaning "Abel's lizards") is a family (or clade) of ceratosaurian theropod dinosaurs. Abelisaurids thrived during the Cretaceous period, mainly on the ancient southern supercontinent of Gondwana, and today their fossil remains are found on the modern continents of Africa, South America, and (western) Europe, as well as on the Indian subcontinent and the island of Madagascar. Abelisaurids possibly first appeared during the Early Jurassic based on the putative abelisaurid Eoabelisaurus from Patagonia and some genera survived until the end of the Mesozoic era, around .

Ornithomimosauria ("bird-mimic lizards") are theropod dinosaurs which bore a superficial resemblance to the modern-day ostrich. They were fast, omnivorous or herbivorous dinosaurs from the Cretaceous Period of Laurasia (now Asia, Europe and North America), as well as possibly Africa. The group first appeared in the Early Cretaceous and persisted until the Late Cretaceous. Primitive members of the group include Nqwebasaurus, Pelecanimimus, Shenzhousaurus, Hexing and Deinocheirus, the arms of which reached 2.4 m (8 feet) in length. More advanced species, members of the family Ornithomi

Ankylosauridae () is a family of armored dinosaurs within Ankylosauria, and is the sister group to Nodosauridae. The oldest known ankylosaurids date to around , and the clade went extinct during the Cretaceous–Paleogene extinction event. These animals were mainly herbivorous and were obligate quadrupeds, with leaf-shaped teeth and robust, scute-covered bodies. Ankylosaurids possess a distinctly domed and short snout, wedge-shaped osteoderms on their skull, scutes along their torso, and a tail club.

Titanosaurs (or titanosaurians; members of the group Titanosauria) were a diverse group of sauropod dinosaurs, including genera from every continent. The titanosaurs were the last surviving group of long-necked sauropods, with taxa still thriving at the time of the extinction event at the end of the Cretaceous. This group includes some of the largest land animals known to have ever existed, such as Patagotitan, estimated at long with a mass of , and the comparably sized Argentinosaurus and Puertasaurus from the same region.

Oviraptorosaurs ("egg thief lizards") are a group of feathered bipedal maniraptoran dinosaurs from the Cretaceous Period of what are now Asia and North America. They are distinct for their characteristically short, beaked, parrot-like skulls, with or without bony crests atop the head. They ranged in size from Caudipteryx, which was the size of a turkey, to the 8-meter-long, 1.4-ton Gigantoraptor. The group (along with all maniraptoran dinosaurs) is close to the ancestry of birds. Some researchers such as Maryanska et al (2002) and Osmólska et al. (2004) have proposed that they may represent pr

Microceratus (meaning "small-horned") is a genus of small ceratopsian dinosaur that lived in the Cretaceous period of Mongolia. It walked on two legs, had short front arms, a characteristic ceratopsian frill and beak-like mouth, and was around long. It was one of the most primitive ceratopsians, or horned dinosaurs, along with Psittacosaurus, which was also discovered in Mongolia.

Hadrosauroidea is a clade or superfamily of ornithischian dinosaurs that includes the "duck-billed" dinosaurs, or Hadrosauridae, and all dinosaurs more closely related to them than to Iguanodon. Their remains have been recovered in Asia, Europe, Africa and the Americas. Many primitive hadrosauroids, such as the Asian Probactrosaurus and Altirhinus, have traditionally been included in a paraphyletic (unnatural grouping) "Iguanodontidae". With cladistic analysis, the traditional Iguanodontidae has been largely disbanded, and probably includes only Iguanodon and perhaps its closest relatives.

Therizinosaurs (; once called segnosaurs) are an extinct group of large herbivorous theropod dinosaurs whose fossils have been mainly discovered from Cretaceous deposits in Asia and North America. Potential fragmentary remains have also been found in Jurassic deposits of Asia and Europe. Various features of the forelimbs, skull and pelvis unite these finds as both theropods and maniraptorans, making them relatives of birds. The name of the representative genus, Therizinosaurus, is derived from the Greek (, 'to reap' or 'scythe') and (, 'lizard'). The older representative, Segnosaurus, is deriv

Caenagnathidae is a family of derived caenagnathoid dinosaurs from the Cretaceous of North America and Asia. They are a member of the Oviraptorosauria, and relatives of the Oviraptoridae. Like other oviraptorosaurs, caenagnathids had specialized beaks, long necks, and short tails, and would have been covered in feathers. The relationships of caenagnathids were long a puzzle. The family was originally named by Raymond Martin Sternberg in 1940 as a family of flightless birds. The discovery of skeletons of the related oviraptorids revealed that they were in fact non-avian theropods, and the disco

Nemegtosauridae is a family of titanosaurian sauropod dinosaurs based on their diplodocid-like skulls. Only three species are known: Nemegtosaurus, Quaesitosaurus and possibly Tapuiasaurus, each from the Cretaceous.

Lithostrotia is a clade of derived titanosaur sauropods that lived during the Early Cretaceous and Late Cretaceous. The group was defined by Upchurch et al. in 2004 as the most recent common ancestor of Malawisaurus and Saltasaurus and all the descendants of that ancestor. Lithostrotia is derived from the Ancient Greek , meaning "inlaid with stones", referring to the fact that many known lithostrotians are preserved with osteoderms. However, osteoderms are not a distinguishing feature of the group, as the two noted by Unchurch et al. include caudal vertebrae with strongly concave front faces (

Eudromaeosauria (International Phonetic Alphabet|; "true dromaeosaurs") is a subgroup of terrestrial dromaeosaurid theropod dinosaurs. They were small to large-sized predators that flourished during the Cretaceous Period. Eudromaeosaur fossils are known almost exclusively from the northern hemisphere.

Megaraptora is a clade of carnivorous theropod dinosaurs. Its derived members, the Megaraptoridae are noted for their large hand claws and powerfully-built forelimbs, which are usually reduced in size in other large theropods. Although undoubtedly members of the clade Tetanurae, their relationships to others members of this group have been subject to dispute.

Ankylosaurinae is a subfamily of ankylosaurid dinosaurs, existing from the Early Cretaceous about 105 million years ago until the end of the Late Cretaceous, about 66 mya. Many genera are included in the clade, such as Ankylosaurus, Pinacosaurus, Euoplocephalus, and Saichania.

Deinocheiridae is an extinct family of ornithomimosaurian dinosaurs, living in Asia and North America from the Aptian until the Maastrichtian, with a possible Late Jurassic record in Europe. The family was originally named by Halszka Osmólska and Roniewicz in 1970, including only the type genus Deinocheirus. In a 2014 study by Yuong-Nam Lee and colleagues and published in the journal Nature, it was found that Deinocheiridae was a valid family. Lee et al. found that based on a new phylogenetic analysis including the recently discovered complete skeletons of Deinocheirus, the type genus, as well

Elasmaria is a clade of ornithopods known from Cretaceous deposits in the former Gondwana (South America, Antarctica, Australia, and possibly Africa) that contains many bipedal ornithopods that were previously considered "hypsilophodonts".

Thescelosauridae is a clade of neornithischians from the Cretaceous of East Asia and North America. The group was originally used as a name by Charles M. Sternberg in 1937, but was not formally defined until 2013, where it was used by Brown and colleagues as the group uniting Thescelosaurus and Orodromeus, based on their phylogenetic results. During a phylogenetic revision of neornithischians by Clint Boyd in 2015, the authorship of Thescelosauridae was given to Brown and colleagues, which meant that the similar name Parksosauridae, informally defined in 2002 by Buchholz, would have had priori

Lognkosauria is a clade of giant long-necked sauropod dinosaurs within the clade Titanosauria. It includes some of the largest and heaviest dinosaurs known. They lived in South America and Asia during the Late Cretaceous period.

Rhabdodontomorpha is a clade of basal iguanodont dinosaurs. This group was named in 2016 in the context of the description, based on Spanish findings of an early member of the Rhabdodontidae. A cladistic analysis was conducted in which it was found that Muttaburrasaurus was the sister species of the Rhabdodontidae sensu Weishampel. Therefore, Paul-Emile Dieudonné and colleagues defined Rhabdodontomorpha as a node-based clade: the group consisting of the last common ancestor of Rhabdodon priscus and Muttaburrasaurus langdoni, and all its descendants. Within the clade Zalmoxes and Mochlodon are

Colossosauria is a clade of titanosaur sauropods from the latest Early Cretaceous through the Late Cretaceous of South America. The group was originally named by Bernardo González-Riga et al. in 2019 and defined as the "most inclusive clade containing Mendozasaurus neguyelap but not Saltasaurus loricatus or Epachthosaurus sciuttoi". The clade contains different taxa depending on the phylogenetic analysis used, in the defining paper the only subgroups were Rinconsauria and Lognkosauria, but alternate phylogenies published previously had also included various similar titanosaurs such as Aeolosau

Jeholosauridae is an extinct group of herbivorous neornithischian dinosaurs from the Cretaceous Period (Aptian - Cenomanian). The family was first proposed by Han et al. in 2012. The jeholosaurids were defined as all neornithischians more closely related to Jeholosaurus shangyuanensis than to Hypsilophodon foxii, Iguanodon bernissartensis, Protoceratops andrewsi, Pachycephalosaurus wyomingensis, or Thescelosaurus neglectus. The Jeholosauridae includes the type genus Jeholosaurus, and also possibly Yueosaurus, Changchunsaurus, and Haya.

Parankylosauria is a group of armored thyreophoran dinosaurs known from the Cretaceous of South America, Antarctica, and Australia. Most analyses place parankylosaurs as a member of the Ankylosauria, in which case the group would have split from other ankylosaurs during the mid-Jurassic period, despite this being unpreserved in the fossil record. Another analysis has proposed that parankylosaurs are instead a distinct lineage of non-ankylosaurian armored dinosaurs with more ancestral anatomy. Several parankylosaurs are characterized by a distinctive frond-like tail weapon (called a 'macuahuitl

Eutitanosauria is a clade of titanosaurs, encompassing the more derived members of the group and characterized by the absence of the hyposphene-hypantrum articulation and possibly the presence of osteoderms. The group was first named by Sanz and colleagues in 1999, who used it to unite the group of Argyrosaurus, Lirainosaurus, Saltasaurus and the Peiropolis titanosaur. However, this definition was not used as it made the group equivalent to Saltasauridae, so Saldago redefined it in 2003 to be all titanosaurs closer to Saltasaurus than Epachthosaurus. This definition created Eutitanosauria as t