A dinosaur footprint of the ichnotaxon Eubrontes giganteus from the East Berlin Formation in Connecticut, USA. This Jurassic aged ichnogenus is possibly from Dilophosaurus or a similar species. #FossilFriday #dinosaur #fossil #ichnology #paleontology #eubrontes #gigandipus #dilophosaurus #theropod

A fossilized crocodylomorph tooth of an Iharkutosuchus makadii from the Csehbánya Formation in Veszprém County, Hungary. Unlike the leaf-shaped teeth of herbivorous crocs like Simosuchus, this genus evolved mammal-like dentition. #FossilFriday #crocodylomorph #fossil #paleontology #iharkutosuchus

A rooted dinosaur tooth of a Nanotyrannus sp. from the Hell Creek Formation in Carter County, Montana, USA. This unserrated basal morphology was previously known as the tooth taxon, Aublysodon amplus. #FossilFriday #dinosaur #fossil #paleontology #aublysodon #nanotyrannus #tyrannosaurid #theropod

A dinosaur tooth of a Nanotyrannus sp. from the Hell Creek Formation in Carter County, Montana, USA. This nanotyrannid eutyrannosaur has two species, N. lancensis and N. lethaeus. Welcome back Nanotyrannus. For good this time. #dinosaur #fossil #paleontology #nanotyrannus #tyrannosaurid #theropod

A dinosaur tooth of an ankylosaur, either Hungarosaurus tormai or cf. Struthiosaurus sp. from the Csehbánya Formation in Veszprém County, Hungary. Hungarosaurus is known for its long forelimbs. #FossilFriday #dinosaur #fossil #paleontology #hungarosaurus #struthiosaurus #ankylosaur #ornithischian

A partial fossilized metatarsal of a theropod, possibly Dzharacursor bissektensis from the Bissekty Formation in Dzharakuduk, Kyzylkum Desert, Uzbekistan. This species was previously referred to Archaeornithomimus. #FossilFriday #dinosaur #fossil #paleontology #dzharacursor #ornithomimid #theropod

A fossilized osteoderm from a Cretaceous aged softshelled turtle, possibly Khunnuchelys kizylkumensis from the Bissekty Formation in Dzharakuduk, Kyzylkum Desert, Uzbekistan. Other species of this genus also occur in China and Kazakhstan. #FossilFriday #turtle #fossil #paleontology #khunnuchelys

Today is the 120th anniversary of the description of #Tyrannosaurus rex and #Albertosaurus sarcophagus in 1905 by Henry Fairfield Osborn, the two species that would define the clade, Tyrannosauridae. A pair of dinosaur teeth, albeit very worn, belonging to these two famous species. 🧪

A partial dinosaur tooth of an indeterminate theropod from the Lourinhã Formation in Peniche, Portugal. It's hard to say what it is given its incomplete nature, but it's possibly either Allosaurus europaeus or a non-Torvosaurus megalosauroid. #FossilFriday #dinosaur #fossil #paleontology #theropod

A rooted dinosaur tooth of an indeterminate pachycephalosaurid from the Hell Creek Formation in Carter County, Montana, USA. Genera include, Pachycephalosaurus, Platytholus, Sphaerotholus, and the controversial Stygimoloch and Dracorex. #FossilFriday #dinosaur #fossil #paleontology #ornithischian

A fossilized crocodilian tooth of a Deinosuchus riogragndensis from the Aguja Formation in Brewster County, Texas, USA. There were multiple species of these giant crocs during the Campanian of North America. #FossilFriday #crocodylomorph #crocodilian #fossil #paleontology #deinosuchus

A dinosaur tooth of an indeterminate hadrosaur, possibly Aquilarhinus palimentus from the Aguja Formation in Brewster County, Texas, USA. Aquilarhinus was previous referred to Kritosaurus and Gryposaurus. #FossilFriday #dinosaur #fossil #paleontology #aquilarhinus #ornithopod #ornithischian

A fossilized crocodilian osteoderm of a Miocene aged Alligator sp. from the Fleming Formation near Point Blank, San Jacinto County, Texas, USA. Based on the age, the species could potentially Alligator mefferdi. #FossilFriday #crocodylomorph #crocodilian #fossil #paleontology #alligator

A partial mosasaur jaw, likely Tylosaurus cf. proriger from the Ozan Formation in Northern Texas, USA. This good sized jaw section has a single nice replacement tooth still preserved. A large number of mosasaurs here appear to be Tylosaurus. #FossilFriday #mosasaur #fossil #paleontology #tylosaurus

A fossilized crocodilian tooth of a Brachychampsa montana from the Hell Creek Formation in Baker, Fallon County, Montana, USA. These extinct alligatorids are know for their bulbous or button-like teeth. #FossilFriday #crocodylomorph #crocodilian #fossil #paleontology #brachychampsa

A trilobite fossil of a cf. Nileus sp. from the Pupiao Formation in Yunnan, China. The species of this undescribed Ordovician aged trilobite is unclear, but these are commonly labeled as Nileus transversus or N. transversis by collectors. #FossilFriday #trilobite #fossil #paleontology #nileus

A dinosaur tooth of an indeterminate tyrannosaurid from the Judith River Formation in Havre, Hill County, Montana, USA. Most isolated teeth of Daspletosaurus and Gorgosaurus are indistinguishable. #FossilFriday #dinosaur #fossil #paleontology #gorgosaurus #daspletosaurus #tyrannosaurid #theropod

A fossilized shark tooth of an Otodus megalodon from New Caledonia. Teeth from this locale are dredged from the bottom of the Pacific Ocean and are often extremely worn. This tooth still retains some remnants of its serrations. #FossilFriday #shark #fossil #paleontology #otodus #carcharocles

A dinosaur tooth of an ankylosaur, possibly Denversaurus schlessmani from the Hell Creek Formation in Baker, Fallon County, Montana, USA. Not being well versed, the bulbous base could also suggest Ankylosaurus. #FossilFriday #dinosaur #fossil #paleontology #denversaurus #ankylosaur #ornithischian

A dinosaur tooth of an indeterminate theropod, possibly Tyrannosaurus rex from the Hell Creek Formation in Harding County, South Dakota, USA. The oval cross-section suggests T. rex, but it could be something else. #FossilFriday #dinosaur #fossil #paleontology #tyrannosaurus #tyrannosaurid #theropod

A fossilized tooth, possibly a squalodontid or Squalodon sp. from the Bone Valley Member, Peace River Formation in the phosphate mines of Florida, USA. These oddly toothed cetaceans are also known as shark-toothed dolphins. #FossilFriday #synapsid #mammal #fossil #paleontology #squalodon #cetacean

A partial dinosaur tooth of an indeterminate sauropod, possibly macronarian from the Lourinhã Formation in Lourinhã, Portugal. Like the Morrison Formation, this deposit has many sauropods such as Lusotitan, Oceanotitan, and Lourinhasaurus. #FossilFriday #dinosaur #fossil #paleontology #sauropod

A dinosaur tooth of an indeterminate carcharodontosaurid from the Kem Kem Group in Morocco. Carcharodontosaurus and the basal (possibly undiagnostic) Sauroniops may be indistinguishable. #FossilFriday #dinosaur #fossil #paleontology #carcharodontosaurus #sauroniops #carcharodontosaurid #theropod

A fossilized fish tooth of an Enchodus petrosus from the Taylor Group in the South Sulphur River of Texas, USA. This commonly found extinct genus is sometimes called the "saber-toothed herring", though it is not actually related to true herring. #FossilFriday #fish #fossil #paleontology #enchodus

A very worn dinosaur tooth of an indeterminate theropod, possibly Ceratosaurus sp. from the Lourinhã Formation in Lourinhã, Portugal. The teeth of Ceratosaurus can be quite compressed as seen in this specimen. #FossilFriday #dinosaur #fossil #paleontology #ceratosaurus #ceratosaurid #theropod

A pair of indeterminate crocodylomorph teeth, possibly alligatoroid from the Aquia Formation in Belvedere, King George County, Virginia, USA. This Paleocene aged deposit produces a number of crocodylomorph genera. #FossilFriday #crocodylomorph #crocodilian #fossil #paleontology

A fossilized crocodilian osteoderm, possibly Thecachampsa sericodon from the Ocala Limestone in the Haile Quarry (Haile Sites) of Alachua County, Florida, USA. This specimen was originally found in multiple pieces. #FossilFriday #crocodylomorph #crocodilian #fossil #paleontology #thecachampsa

A fossilized tooth of a woolly mammoth or Mammuthus primigenius in Cotswold Water Park, Ashton Keynes, Wiltshire, England. Unfortunately, this specimen suffered damage during transport and had to be glued back together. #FossilFriday #synapsid #mammal #fossil #paleontology #mammuthus #mammoth

A plesiosaur vertebra of an indeterminate pliosaurid from the Oxford Clay from Oday Common, Abingdon, Oxfordshire, United Kingdom. This deposit contains multiple genera such as Liopleurodon and Pliosaurus making identification difficult. #FossilFriday #plesiosaur #pliosaur #fossil #paleontology

Partial pair of fossilized fish fin bones of a Protosphyraena sp. from the Niobrara Chalk in Kansas, USA. The distinct saw-like pectoral fins of this Cretaceous aged fish are easily recognizable. #FossilFriday #fish #fossil #paleontology #protosphyraena

A mosasaur jaw of a Halisaurus arambourgi from the Couche III in the phosphate mines of Oued Zem, Khouribga, Morocco. Halisaurus teeth resemble those of its relative, Pluridens serpentis, but lack enamel folds towards the base of the crown. #FossilFriday #mosasaur #fossil #paleontology #halisaurus

A gastropod fossil of a Campeloma nebrascensis from the Hell Creek Formation in Harding County, South Dakota, USA. This Cretaceous aged freshwater snail lived at the end of the Mesozoic with the genus surviving to the present day. #FossilFriday #gastropod #fossil #paleontology #campeloma #snail

Turiasaurians are quite weird. Their teeth appear quite commonly in various Middle Jurassic deposits while rarer in the Upper Jurassic. Collectors often call this cf. Atlasaurus or Cetiosaurus mogrebiensis, but it's likely an undescribed turiasaurian genus. #dinosaur #fossil #paleontology #sauropod

A fossilized tooth of a Pinckney's capybara or Neochoerus pinckneyi from Jefferson County, Florida, USA. This large Pleistocene aged rodent or cavy was a North American relative of capybaras. #FossilFriday #synapsid #mammal #fossil #paleontology #neochoerus #capybara #rodent

A dinosaur tooth of a diplodocoid sauropod, possibly Rebbachisaurus garasbae from the Kem Kem Group in Taouz, Morocco. There's more than one morphology so it's difficult to say which teeth belong to this rebbachisaurid species. #FossilFriday #dinosaur #fossil #paleontology #rebbachisaurus #sauropod

Three fossilized crabs of Ranilia muricata or muricate frog crab from Intercoastal Formation in Liberty County, Florida, USA. This basal group of burrowing crab is known for its frog-like body. #FossilFriday #crustacean #crab #fossil #paleontology #ranilia

A fossilized fish scale of a Glyptolepis paucidens from the Achanarras Limestone Member in the Achanarras Quarry of Caithness, Scotland. This holoptychiid lobe-finned fish species lived during the Middle Devonian. #FossilFriday #fish #fossil #paleontology #glyptolepis

A fossilized shark tooth of a Leptostyrax macrorhiza from the Kem Kem Group in Taouz, Morocco. This species of lamniform or mackerel shark appears to have been tolerant of fresh or brackish water and encountered dinosaurs like Spinosaurus. #FossilFriday #shark #fossil #paleontology #leptostyrax

Small tyrannosaur teeth can be difficult to identify, but T. rex teeth are typically blunt with serrations wrapping around the tip. They are not always oval in cross-section with maxillary teeth being more rectangular. #dinosaur #fossil #paleontology #tyrannosaurus #tyrannosaurid #theropod

A rooted mosasaur tooth of a Prognathodon currii from the Couche III in the phosphate mines of Sidi Chennane, Oued Zem, Khouribga, Morocco. This species is durophageous compared than its contemporary and close relative Thalassotitan atrox. #FossilFriday #mosasaur #fossil #paleontology #prognathodon

A partial Cretaceous coelacanth jaw of an Axelrodichthys lavocati from the Kem Kem Group in Hassi Zguilma, Morocco. This mawsoniid coelacanthiform species was formally (and may still be) assigned to the genus Mawsonia. #FossilFriday #fish #coelacanth #fossil #paleontology #axelrodichthys #mawsonia

While the most familiar chondrichthyan in the Kem Kem Group is the sawskate Onchopristis, there are also the more shark-like hybodonts like Tribodus present in these deposits. True sharks are also present such as Cenocarcharias and Haimirichia. #shark #fossil #paleontology #tribodus

A dinosaur tooth with restoration, possibly cf. Gorgosaurus libratus from the Judith River Formation in Havre, Hill County, Montana, USA. Size would usually suggest Daspletosaurus, but a DSDI of 0.76 says otherwise. #FossilFriday #dinosaur #fossil #paleontology #gorgosaurus #tyrannosaurid #theropod

A partial plesiosaur tooth root (no crown) of an indeterminate pliosaurid from the Oxford Clay from Oday Common, Abingdon, Oxfordshire, United Kingdom. Some of the pliosaur genera found here are Pliosaurus, Simolestes, and Liopleurodon. #FossilFriday #plesiosaur #pliosaur #fossil #paleontology

Majungasaurus is quite unique in being relatively "small" as the apex predator in its habitat. How many Majungasaurus does it take to kill a Rapetosaurus that's not already dying or a juvenile? I don't know. Maybe impossible. #dinosaur #fossil #paleontology #majungasaurus #abelisaurid #theropod

A dinosaur tooth, possibly cf. Gorgosaurus libratus from the Judith River Formation in Havre, Hill County, Montana, USA. The tooth position and DSDI of 0.77 suggest Gorgosaurus affinity over Daspletosaurus species. #FossilFriday #dinosaur #fossil #paleontology #gorgosaurus #tyrannosaurid #theropod

A dinosaur tooth of an indeterminate theropod, possibly an abelisaurid from the Grès supérieurs Formation in the Savannakhet Province of Laos. The narrow profile and straight distal edge is similar to similarly aged abelisaurids. #FossilFriday #dinosaur #fossil #paleontology #abelisaurid #theropod

With a crown height just short of 4 inches, this theropod was likely the largest predator its environment. The tooth may or may not be megalosauroid, but large bodied Middle Jurassic megalosaurid material is sometimes attributed to cf. Torvosaurus sp. #dinosaur #fossil #paleontology #theropod

A dinosaur tooth of an indeterminate theropod, possibly a carcharodontosaurid from the Elrhaz Formation in Gadoufaoua, Niger. This odd looking tooth morphology could be related to the Cenomanian Tameryraptor markgrafi. #FossilFriday #dinosaur #fossil #paleontology #carcharodontosaurid #theropod

Ridges like these are found throughout theropods like tyrannosauroids and ceratosaurians. Still indeterminate, but the deposit is notable for ceratosaurid teeth which are fairly uncommon compared to younger Upper Jurassic deposits where they become rare. #dinosaur #fossil #paleontology #theropod