Troodontidae

Troodon ( ; Troödon in older sources) is a controversial genus of relatively small, bird-like theropod dinosaurs definitively known from the Campanian age of the Late Cretaceous period (about 77 million years ago). It includes at least one species, Troodon formosus, known from Montana. Discovered in October 1855, T. formosus was among the first dinosaurs found in North America, although it was thought to be a lizard until 1877.

Troodontidae is a clade of bird-like theropod dinosaurs from the Late Jurassic to Late Cretaceous. During most of the 20th century, troodontid fossils were few and incomplete and they have therefore been allied, at various times, with many dinosaurian lineages. More recent fossil discoveries of complete and articulated specimens (including specimens which preserve feathers, eggs, embryos, and complete juveniles), have helped to increase understanding about this group. Anatomical studies, particularly studies of the most primitive troodontids, like Sinovenator, demonstrate striking anatomical s

Saurornithoides ( ) is a genus of troodontid maniraptoran dinosaur, which lived during the Late Cretaceous period. These creatures were predators, which could run fast on their hind legs and had excellent sight and hearing. The name is derived from the Greek stems saur~ (lizard), ornith~ (bird) and eides (form), referring to its bird-like skull.

Byronosaurus is a genus of troodontid dinosaur from the Late Cretaceous Period of Mongolia.

Jinfengopteryx (from , 'golden phoenix', the queen of birds in Chinese folklore, and , meaning 'feather') is a genus of maniraptoran dinosaur. It was found in the Qiaotou Member of the Huajiying Formation of Hebei Province, China, and is therefore of uncertain age. The Qiaotou Member may correlate with the more well-known Early Cretaceous Yixian Formation, and so probably dates to around 122 Ma (122 million years) ago.

Sinornithoides (meaning "Chinese bird form") is a genus of troodontid theropod dinosaurs that lived during the Early Cretaceous (Aptian or Albian stage, around 113 million years ago) of Inner Mongolia, China. It contains only a single species, S. youngi. Sinornithoides measured approximately long, and probably ate invertebrates and other small prey.

genus of reptiles (fossil)

Sinovenator (meaning "Chinese hunter") is a genus of troodontid dinosaur from China. It is from the early Cretaceous Period.

Borogovia is a troodontid theropod dinosaur genus which lived during the Late Cretaceous Period, in what is now Mongolia. It contains one species, Borogovia gracilicrus.

genus of reptiles (fossil)

Paronychodon (meaning "beside claw tooth") is an extinct theropod dinosaur genus. It is a tooth taxon, often considered dubious because of the fragmentary nature of the fossils, which include "buckets" of teeth from many disparate times and places but no other remains, and should be considered a form taxon.

Xixiasaurus () is a genus of troodontid dinosaur that lived during the Late Cretaceous Period in what is now China. The only known specimen was discovered in Xixia County, Henan Province, in central China, and became the holotype of the new genus and species Xixiasaurus henanensis in 2010. The names refer to the areas of discovery, and can be translated as "Henan Xixia lizard". The specimen consists of an almost complete skull (except for the hindmost portion), part of the lower jaw, and teeth, as well as a partial right forelimb.

Latenivenatrix, meaning "hiding huntress", is a genus of large troodontid known from a single species, L. mcmasterae. Along with the contemporary Stenonychosaurus, it is known from non-tooth fossils that were formerly assigned to the now potentially dubious genus Troodon. Although described as separate, it has been considered a junior synonym of Stenonychosaurus.

Stenonychosaurus (meaning "narrow claw lizard") is a disputed genus of troodontid dinosaur from the Late Cretaceous Dinosaur Park Formation of Alberta, Canada, as well as possibly the Two Medicine Formation. The type and only species, S. inequalis, was named by Charles Mortram Sternberg in 1932, based on a foot, fragments of a hand, and some caudal vertebrae from the Late Cretaceous of Alberta. S. inequalis was reassigned in 1987 by Phil Currie to the genus Troodon, which was reverted by the recognition of Stenonychosaurus as a separate genus from the possibly dubious Troodon in 2017 by Evans

Linhevenator is a genus of short-armed troodontid theropod dinosaur from the Late Cretaceous (Campanian) Bayan Mandahu Formation of Bayan Mandahu, Inner Mongolia, China.

Geminiraptor (meaning "twin seizer") is a genus of troodontid theropod dinosaur that lived in North America during the Early Cretaceous period. Geminiraptor was a small, ground-dwelling bipedal carnivorous paravian. The type species of Geminiraptor is G. suarezarum.

Gobivenator is an extinct genus of troodontid theropod dinosaur known from the late Campanian Djadokhta Formation of central Gobi Desert, Mongolia. It contains a single species, Gobivenator mongoliensis. G. mongoliensis is known from a single individual, which represents the most complete specimen of a Late Cretaceous troodontid currently known.

Urbacodon (meaning "URBAC tooth") is a genus of troodontid theropod dinosaur. Two species have been described, both of which are known from a partial dentary: U. itemirensis from the Dzharakuduk Formation (Cenomanian) of Uzbekistan and U. norelli from the Iren Dabasu Formation of China. Possible remains are also known from the Bissekty Formation (Turonian) of Uzbekistan.

Euronychodon ("European claw tooth") is the name given to a genus of coelurosaur dinosaur from the Late Cretaceous of Europe and Asia. A small-sized dinosaur estimated to measure around in length, Euronychodon is known from teeth only. These are similar to those of another coelurosaur tooth genus, Paronychodon.

Hesperornithoides (meaning "western bird form"; nicknamed "Lori") is a genus of troodontid theropod dinosaur that lived in North America during the Late Jurassic period.

Pectinodon is a genus of troodontid theropod dinosaurs from the end of the Maastrichtian age of the Late Cretaceous period (66 mya). It currently contains a single valid species, Pectinodon bakkeri (sometimes classified as Troodon bakkeri), known only from teeth.

Koparion is a genus of small coelurosaurian theropod dinosaur, from the late Jurassic Period (Kimmeridgian stage), of Utah. It contains the single named species Koparion douglassi which is known only from a single isolated tooth.

Tochisaurus (meaning "Ostrich lizard") is a genus of small troodontid theropod dinosaur from the Late Cretaceous Period of Mongolia. The type (and only named) species is Tochisaurus nemegtensis.

Philovenator (literally meaning "love hunter") is an extinct genus of troodontid paravian dinosaurs from the Wulansuhai Formation (dated to the Campanian age, sometime between 75 and 71 million years ago) of Inner Mongolia, China. Its specific name honors Phillip J. Currie.

Sinusonasus is a genus of dinosaurs from the Early Cretaceous Period, recovered from the Yixian Formation. It lived in what is now the Liaoning Province of China. Sinusonasus was a theropod, specifically a troodontid dinosaur.

Papiliovenator (meaning "butterfly hunter", after a butterfly-shaped feature on its first two dorsal vertebrae) is a genus of troodontid theropod dinosaur from the Bayan Mandahu Formation of Inner Mongolia, China. The type and only species is Papiliovenator neimengguensis.

Albertavenator (meaning "Alberta hunter") is a genus of small-bodied troodontid theropod dinosaur that lived during the early Maastrichtian stage of the Late Cretaceous period, approximately 71 million years ago. It is known from the Horseshoe Canyon Formation in Alberta, Canada, and is currently represented by a single species, Albertavenator curriei. The species name honors Canadian paleontologist Philip J. Currie for his extensive contributions to theropod research. The animal is known from parts of the skull.

Daliansaurus (meaning "Dalian reptile") is a genus of small troodontid theropod dinosaur, measuring approximately long, from the Early Cretaceous of China. It contains a single species, D. liaoningensis, named in 2017 by Shen and colleagues from a nearly complete skeleton preserved in three dimensions. Daliansaurus is unusual in possessing an enlarged claw on the fourth digit of the foot, in addition to the "sickle claw" found on the second digit of the feet of most paravians. It also has long metatarsal bones, and apparently possesses bird-like uncinate processes (a first among troodontids).

Tamarro (named after a mythological creature in local culture) is a genus of troodontid theropod from the Late Cretaceous Talarn Formation (Tremp Group) of Spain. The genus contains a single species, Tamarro insperatus, known from a partial metatarsal described in 2021.

species of reptile (fossil)

Jianianhualong (meaning "Jianianhua dragon") is a genus of troodontid theropod dinosaur from the Early Cretaceous of China. It contains a single species, Jianianhualong tengi, named in 2017 by Xu Xing and colleagues based on an articulated skeleton preserving feathers. The feathers at the middle of the tail of Jianianhualong are asymmetric, being the first record of asymmetrical feathers among the troodontids. Despite aerodynamic differences from the flight feathers of modern birds, the feathers in the tail vane of Jianianhualong could have functioned in drag reduction whilst the animal was mo

Xenovenator () is an extinct genus of troodontid theropod dinosaurs known from the Late Cretaceous (Campanian age) of North America. The type species of the genus, Xenovenator espinosai, is known from fragmentary skull bones found in the Cerro del Pueblo Formation of Mexico. It is characterized by an unusually expanded and rugose skull roof, somewhat comparable to that seen in pachycephalosaurs. This may imply Xenovenator individuals engaged in combat with other members of their species, a behavior for which adaptations had not been previously observed in non-avian paravians.

Liaoningvenator (meaning "Liaoning hunter") is a genus of troodontid theropod dinosaur from the Early Cretaceous of China. It contains a single species, L. curriei, named after paleontologist Phillip J. Currie in 2017 by Shen Cai-Zhi and colleagues from an articulated, nearly complete skeleton, one of the most complete troodontid specimens known. Shen and colleagues found indicative traits that placed Liaoningvenator within the Troodontidae. These traits included its numerous, small, and closely packed teeth, as well as the vertebrae towards the end of its tail having shallow grooves in place

species of reptile (fossil)

Harenadraco (meaning "sand dragon") is an extinct genus of troodontid theropod dinosaurs from the Late Cretaceous Baruungoyot Formation of Mongolia. The genus contains a single species, H. prima, known from a fragmentary skeleton. Harenadraco represents the first troodontid known from the Baruungoyot Formation. Since members of this family are also known from the Nemegt and Djadochta Formations, the discovery of Harendraco indicates that troodontids were important faunal components of every formation within the Nemegt Basin.

Hypnovenator (meaning "sleep hunter") is an extinct genus of troodontid theropod dinosaurs from the Early Cretaceous (Albian) Ohyamashimo Formation of Japan. The genus contains a single species, Hypnovenator matsubaraetoheorum, known from a partial skeleton. Hypnovenator is the only troodontid currently known from Japan, and it represents the oldest definitive member of the subgroup Troodontinae.

Jinfengopteryginae is a subfamily of bird-like theropod dinosaurs known from the Cretaceous of Eurasia. This group includes relatively few genera, with members discovered in 2005 but the name erected in 2012. Like other troodontids, this group of dinosaurs resided in the Paraves potentially close to the Avialae.