Notable Dinosaurs

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Nanotyrannus
Artist's reconstructionConnor Ashbridge, CC BY 4.0

Nanotyrannus

“dwarf tyrant”
TheropodcarnivoreLate Cretaceousdisputed

A small tyrannosaur or a teenage T. rex? One of palaeontology's longest arguments

Overview

Nanotyrannus is a genus of tyrannosauroid dinosaur that lived in what is now western North America during the Maastrichtian age of the Late Cretaceous, 67 to 66 million years ago. Its fossils are mainly known from the Hell Creek Formation. It was one of the last-known non-avian dinosaurs and lived until the Cretaceous–Paleogene extinction event. The first named species, N. lancensis, was described as a new species of Gorgosaurus in 1946 by Charles W. Gilmore based on a single skull. Re-examination of the specimen in 1988 by Robert T. Bakker, Michael Williams and Philip J. Currie moved the species to a new genus of tyrannosaurid, named Nanotyrannus in reference to its small body size compared to other tyrannosaurids.

Source: Wikipedia

Why it matters

  • Named in 1988 from a skull first described in 1946 as Gorgosaurus.
  • Many researchers see it as a juvenile Tyrannosaurus; others point to different tooth counts and arm proportions.
  • The 'Dueling Dinosaurs' fossil, a tyrannosaur entangled with a Triceratops, is central to the debate.

Classification & discovery

Group
Dinosaur · Theropod · Nanotyrannidae
Parent taxon
Nanotyrannidae
Diet
carnivore
Environment
terrestrial
Life habit
ground-dwelling, solitary
Named
by Bakker et al. in 1988

When it lived

72.2 – 66 million years ago · Cretaceous

PermianTriassicJurassicCretaceousPaleogene6080100120140160180200220240260280300End-Cretaceous extinction, 66 MaDimetrodon: 298.9–266.9 Ma · A sail-backed predator that is closer to mammals than to any dinosaurDimetrodonHerrerasaurus: 237–227.3 Ma · An early predator from the dawn of the dinosaurs, named after the goat herder who found itHerrerasaurusEoraptor: 233.6–227.3 Ma · One of the very first dinosaurs, a dog-sized omnivore from 231 million years agoEoraptorCoelophysis: 227.3–192.9 Ma · A slender Triassic predator found by the hundreds at Ghost RanchCoelophysisPlateosaurus: 227.3–199.5 Ma · The first big plant-eater: a two-legged Triassic forerunner of the sauropodsPlateosaurusMegalosaurus: 205.7–66 Ma · The first dinosaur ever named, in 1824, decades before the word 'dinosaur' existedMegalosaurusPlesiosaurus: 205.7–66 Ma · The long-necked sea reptile Mary Anning found, often mistaken for a dinosaurPlesiosaurusDilophosaurus: 201.4–184.2 Ma · A seven-metre Early Jurassic predator with twin head crests, and no venom or neck frillDilophosaurusHeterodontosaurus: 201.4–184.2 Ma · A fox-sized dinosaur with tusks, incisors and cheek teeth all in one mouthHeterodontosaurusCryolophosaurus: 199.5–184.2 Ma · The first dinosaur named from Antarctica, with a pompadour-like crestCryolophosaurusMamenchisaurus: 168.2–113.2 Ma · The longest neck of any animal: up to 15 metres, half of its bodyMamenchisaurusKulindadromeus: 168.2–165.3 Ma · A plant-eater with feather-like fuzz, suggesting all dinosaurs could grow feathersKulindadromeusAnchiornis: 168.2–152.2 Ma · The first dinosaur with its whole colour pattern reconstructedAnchiornisYi: 165.3–154.8 Ma · A pigeon-sized dinosaur with bat-like membrane wingsYiStegosaurus: 161.5–93.9 Ma · Plates on its back, spikes on its tail and a famously small headStegosaurusAllosaurus: 161.5–137.1 Ma · The top predator of the Jurassic plains of North AmericaAllosaurusBrachiosaurus: 157.9–143.1 Ma · The giraffe of the dinosaur world, with front legs longer than its hind legsBrachiosaurusDiplodocus: 157.9–143.1 Ma · A 26-metre whip-tailed giant known from some of the most complete sauropod skeletonsDiplodocusApatosaurus: 157.9–143.1 Ma · A stockier cousin of Diplodocus with an extraordinarily thick neckApatosaurusBrontosaurus: 154.8–143.1 Ma · The dinosaur that was declared a mistake in 1903 and resurrected in 2015BrontosaurusIguanodon: 154.8–66 Ma · The second dinosaur ever named, whose thumb spike was first mistaken for a nose hornIguanodonCompsognathus: 154.8–145.1 Ma · A chicken-sized hunter and the first dinosaur known from a complete skeletonCompsognathusSupersaurus: 154.8–143.1 Ma · Possibly the longest dinosaur known from reasonably complete remainsSupersaurusEuropasaurus: 152.2–149.2 Ma · A sauropod shrunk to the size of a cow by life on a small islandEuropasaurusArchaeopteryx: 149.2–121.4 Ma · The feathered 'first bird' that tied birds to dinosaurs two years after Darwin's OriginArchaeopteryxMaraapunisaurus: 149.2–143.1 Ma · The lost vertebra that may have belonged to the largest dinosaur of allMaraapunisaurusDeinonychus: 143.1–93.9 Ma · The claw that launched the Dinosaur RenaissanceDeinonychusCarcharodontosaurus: 143.1–72.2 Ma · An African giant with serrated, shark-like teeth, rediscovered after its bones were bombedCarcharodontosaurusBaryonyx: 139.1–110.1 Ma · A crocodile-snouted fish-eater found by an amateur in a Surrey clay pitBaryonyxPsittacosaurus: 137.1–100.5 Ma · The best-understood dinosaur: colour, skin, bristles and even its cloaca are knownPsittacosaurusUtahraptor: 137.1–132.6 Ma · The largest raptor, with a 24-centimetre killing clawUtahraptorSpinosaurus: 125.8–72.2 Ma · The longest predatory dinosaur, a sail-backed river hunter with a paddle tailSpinosaurusSinosauropteryx: 125.8–119.6 Ma · The first non-bird dinosaur found with feathers, and the first with a known colourSinosauropteryxYutyrannus: 125.8–119.6 Ma · A nine-metre tyrannosaur relative covered in shaggy feathersYutyrannusAmargasaurus: 125.8–121.4 Ma · A small sauropod with a double row of spines down its neckAmargasaurusConcavenator: 125.8–121.4 Ma · A Spanish predator with a strange hump before the hips and possible quill knobsConcavenatorMicroraptor: 121.4–113.2 Ma · A crow-sized dinosaur with four wings and glossy black feathersMicroraptorBorealopelta: 121.4–113.2 Ma · An armoured dinosaur so well preserved it looks like it is sleepingBorealopeltaOuranosaurus: 121.4–66 Ma · A sail-backed plant-eater from the Sahara, when it was a river deltaOuranosaurusNigersaurus: 121.4–100.5 Ma · The 'Mesozoic cow' whose vacuum-cleaner mouth held 500 teethNigersaurusPatagotitan: 113.2–100.5 Ma · The best-known of the super-giants: six individuals from one Patagonian ranchPatagotitanGiganotosaurus: 113.2–106.3 Ma · A South American predator that rivalled Tyrannosaurus in sizeGiganotosaurusLeaellynasaura: 113.2–110.1 Ma · A small polar dinosaur that lived through months of winter darknessLeaellynasauraArgentinosaurus: 110.1–106.3 Ma · Possibly the heaviest land animal ever, known from a handful of enormous bonesArgentinosaurusDeinocheirus: 100.5–66 Ma · For 50 years only a pair of 2.4-metre arms were known; the rest was a hump-backed, duck-billed surpriseDeinocheirusShantungosaurus: 100.5–66 Ma · The largest duck-bill and the biggest non-sauropod dinosaur knownShantungosaurusMosasaurus: 100.5–61.7 Ma · A giant marine lizard from the Maastricht chalk, the fossil that launched the idea of extinctionMosasaurusGallimimus: 93.9–66 Ma · The largest ostrich dinosaur, built for speed on the Gobi plainsGallimimusVelociraptor: 89.8–66 Ma · A turkey-sized, feathered hunter, not the man-sized monster of the moviesVelociraptorOviraptor: 89.8–72.2 Ma · Named an egg thief for a crime it did not commit: it was brooding its own nestOviraptorEdmontosaurus: 89.8–66 Ma · The duck-bill known from 'mummies' with skin, hooves and a fleshy crestEdmontosaurusPteranodon: 89.8–72.2 Ma · Not a dinosaur at all: a flying reptile with a seven-metre wingspan and a toothless beakPteranodonHadrosaurus: 85.7–66 Ma · The first dinosaur skeleton ever mounted for the public, in Philadelphia in 1868HadrosaurusTyrannosaurus: 83.6–66 Ma · The tyrant king: the most studied predator that ever walked the EarthTyrannosaurusTriceratops: 83.6–66 Ma · Three horns, a bony frill and the most common large herbivore of the final dinosaur ageTriceratopsAnkylosaurus: 83.6–66 Ma · A living tank with a bone-crushing tail clubAnkylosaurusParasaurolophus: 83.6–72.2 Ma · A duck-billed dinosaur whose metre-long crest worked like a tromboneParasaurolophusPachycephalosaurus: 83.6–66 Ma · A dome of solid bone 25 centimetres thick, probably for ramming rivalsPachycephalosaurusDreadnoughtus: 83.6–72.2 Ma · A giant named after battleships, known from an unusually complete skeletonDreadnoughtusMaiasaura: 83.6–72.2 Ma · The dinosaur that proved parents cared for their youngMaiasauraTroodon: 83.6–66 Ma · The 'smartest dinosaur', with big eyes and a big brain, now a name in troubleTroodonZuul: 83.6–72.2 Ma · An ankylosaur named after a movie demon, with skin and armour still in placeZuulCarnotaurus: 72.2–66 Ma · A horned predator with the smallest arms of any large theropodCarnotaurusTherizinosaurus: 72.2–66 Ma · A pot-bellied, long-necked theropod with metre-long claws, the longest of any animalTherizinosaurusNanotyrannus: 72.2–66 Ma · A small tyrannosaur or a teenage T. rex? One of palaeontology's longest argumentsNanotyrannusMajungasaurus: 72.2–66 Ma · The only dinosaur with direct evidence of cannibalismMajungasaurusAustroraptor: 72.2–66 Ma · The largest raptor of the southern hemisphere, with a long snout and short armsAustroraptor

Where it was found

Montana · Countries with fossils: US

6 fossil occurrences in the Paleobiology Database · Rock formations: Hell Creek, Lance

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Size

Human, 1.8 m
Nanotyrannus
Nanotyrannus · Height 1.8 m
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Length 5.5 m · Mass 600 kg · Size estimates are editorial, from the literature; silhouettes from PhyloPic.

Length
5.5 m
Height
1.8 m
Mass
600 kg
First appearance
72.2 MaMaastrichtian
Last appearance
66 Ma
Span of the fossil record
6.2 million years
Fossil occurrences
6US
Year named
1988Bakker et al.

Sources

WikipediaPaleobiology DatabaseWikidata

Image: Zissoudisctrucker, CC BY-SA 4.0 · CC BY-SA 4.0 · image page

Life restoration: Connor Ashbridge, CC BY 4.0 · CC BY 4.0 · image page

Silhouette: Scott Hartman (PhyloPic) · license

Text: Wikipedia (CC BY-SA 4.0). Taglines, highlights and size estimates are editorial.