Strangest Ones: 20 of the Weirdest Dinosaurs That Ever Existed

Leave a comment / / Updated on: 24th September 2023

strangest dinosaurs

The fossil record is populated by several of the strangest dinosaurs. 

Paleontologists have identified more than 1,000 species of dinosaurs so far. 

A large number of these incredible beasts were strange indeed. 

In fact, some of these dinosaurs were so strange they’d probably be circus characters if they were still living today. 

Not only do they look different from their relatives, many of them exhibited unexpected behavioral traits. 

From dinosaurs with hundreds of teeth to those with strange-looking head adornments, here’s a list of 20 of the weirdest dinosaurs that have ever existed. 

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20. Protoceratops

strangest dinosaurs
Protoceratops on a white background | cyoginan via iStock
Name Meaning“First horned face”
EraMesozoicLate Cretaceous
ClassificationDinosauria, Ornithischia & Ceratopsia
Height50–60 centimeters (19.7–23.6 inches)
Length2–2.5 meters (6.6–8.2 feet)
Weight62–104 kg (137–229 lbs)

The Protoceratops is famous for its similarities with the mythological griffin—a legendary creature with the head, wings, and talons of an eagle and the body of a lion. 

But the real Protoceratops did not have wings. 

It did have an elaborate neck frill and a beaked mouth that looked like the beaks of a parrot.

Protoceratops was small compared to other ceratopsid dinosaurs, with an average length of about 2 to 2.5 meters (6.6–8.2 feet). 

This dinosaur’s tail was unusually long and had a sail-like structure on its end.

This is another feature not seen in any of its other relatives.  

The exact function of this sail is unknown, but it may have been used for display or swimming. 

19. Mamenchisaurus

strangest dinosaurs
Mamenchisaurus 3D render – Elenarts108 via Istock
Name Meaning“Mamenchi Lizard”
EraMesozoic – Late Jurassic
ClassificationDinosauria, Saurischia & Sauropoda
Height10–15 meters (33–49 feet)
Length21 to 22 meters (69 to 72 feet)
Weight20–40 metric tons (44,000–88,000 pounds)
LocationChina (Asia)

Sauropod dinosaurs are known for their remarkably long necks, and the Mamenchisaurus was not an exception. 

In fact, this dinosaur may have had the longest neck of all known sauropods, with an estimated length of about 9.3 meters (31 feet). 

The total length of the Mamenchisaurus’ body has been estimated to be about 21 to 22 meters (69–72 feet). 

This means the neck would have formed close to half its entire body length. 

Expectedly, the Mamenchisaurus was one of the longest dinosaurs to have ever lived.

The tail was long as well, and the body was supported on strong muscular legs with thick pads of fibrous tissues on the heels to cushion the dinosaur’s massive weight.

18. Nasutoceratops

strangest dinosaurs
Nasutoceratops was a herbivorous Ceratopsid dinosaur that lived in Utah, USA during the Cretaceous Period – CoryFord via Istock
Name Meaning“Big-nosed horn face”
EraMesozoic – Late Cretaceous
ClassificationDinosauria, Ornithischia & Ceratopsia
Height1.8-2.1 meters (6-7 feet)
Length4.5 meters (14.8 feet) 
Weight1.5 tons (3,000 lbs)
LocationUSA (North America)

Nasutoceratops was a large ceratopsian dinosaur, which means it had a large frill and an impressive array of facial horns. 

The Nasutoceratops brow horns are the longest of any centrosaurine dinosaur, extending almost to the tip of the dinosaur’s snout.

But this was not the most unusual thing about this dinosaur. 

What makes the Nasutoceratops so bizarre is the shape and orientation of the horns. 

The horns were rounded and pointed forward, similar to the horns of modern cattle. 

This herbivorous dinosaur lived in North America during the Late Cretaceous Period about 75 million years ago. 

17. Yi qi

strangest dinosaurs
Yi Qi standing upright expanding its feathers | Vaderxl via Dinopedia Fandom
NameYi Qi
Name Meaning“Strange wings”
EraMesozoic — Middle Jurassic 
ClassificationDinosauria, Saurischia,‭ ‬Theropoda
Length0.34 meters (one foot) 
Weight380 grams (0.84 pounds)
LocationChina (Asia) 

Yi qi has the shortest name of any known dinosaur. 

And if that isn’t weird enough, this dinosaur also had an incredibly bizarre appearance. 

Yi qi had membranous gliding wings made of skin, very similar to the wings of bats. 

Evidence also suggests that it had feathers all over its body. 

Interestingly, despite having feathers and membranous wings, this dinosaur was still incapable of flight. 

The wings were only useful for gliding and display.

Yi qi was also a very small dinosaur, with an estimated weight of less than one pound. 

It lived in China during the Middle Jurassic Period about 150 million years ago. 

16. Halszkaraptor

strangest dinosaurs
Halzkaraptor | Tomopteryx via Wikipedia CC BY-SA 4.0
Name Meaning“Halszka’s seizer”
EraMesozoic — Late Cretaceous
ClassificationDinosauria, Saurischia,‭ ‬Theropoda
Height45 centimeters (1.47 feet)
Length60 centimeters (1.9 feet)
Weight0.72–1.6 kilograms (1.6–3.5 pounds)
LocationChina (Asia) 

This strange dinosaur looked more like a duck or other types of waterfowl than a typical dinosaur. 

Yet, it was a theropod dinosaur in the same family as dromaeosaurids, such as the Velociraptor.

It was a tiny dinosaur, about the same size as a mallard duck. 

Halszkaraptor had an extremely long, swan-like neck with a small head that only measured seven centimeters (2.8 inches). 

The 20-centimeter-long (7.9 inches) neck of this dinosaur takes up more than half its entire body length. 

The combination of a swan-like neck, a long tail, and forelimbs modified into flippers suggests that this dinosaur lived a semi-aquatic lifestyle and may have hunted fish and other aquatic creatures—a behavior rarely seen in dinosaurs. 

15. Deinocheirus

strangest dinosaurs
Deinocheirus 3D render | elenarts108 via iStock
Name Meaning“Terrible Hand”
EraMesozoic – Late Cretaceous
ClassificationDinosauria,‭ Saurischia & Theropoda
Height5 meters (16 feet)
Length11.0 m (36.0 ft)
Weight 6.5 tons (7.2 short tons)

For many years after it was initially discovered in 1970, the true appearance of this dinosaur remained a mystery. 

It was only known for its enormous, three-fingered hands that looked more like a pirate’s grappling hooks. 

The dinosaur’s name, which translates as “horrible hands,” is a reference to these bizarre 2.4-meter-long (7.9-foot) hands. 

Deinocheirus had the largest arm of any known bipedal dinosaur. 

Additional fossils of the Deinocheirus were later discovered and described in 2014, which helped scientists get a complete picture of what this bulky ornithomimosaur dinosaur may have looked like. 

14. Parasaurolophus

strangest dinosaurs
Parasaurolophus from the Cretaceous era 3D illustration – Warpaintcobra via Istock
Name Meaning“Near crested lizard”
EraMesozoic – Late Cretaceous
ClassificationDinosauria,‭ ‬Ornithischia‭ & Ornithopoda
Height4.9 meters (16 feet)
Length11.45 meters (37.6 feet)
Weight2.7 tons (5,952 lbs)
LocationNorth America

Parasaurolophus was a duck-billed dinosaur famous for its elaborate cranial crest. 

The long crest of this dinosaur extends from its snout and curves backward to the back of its head like a trombone. 

This hollow crest may have served acoustic purposes, meaning it may have produced a wide range of vocalizations for communication or mating display. 

Parasaurolophus was a quadrupedal dinosaur, but it could also switch to a bipedal posture to access vegetation higher up in trees. 

It lived during the Late Cretaceous Period in parts of western North America and probably in Asia as well. 

13. Amargasaurus

strangest dinosaurs
Amargasaurus was a herbivorous sauropod dinosaur that lived in Argentina in the Cretaceous Period – CoreyFord via Istock
Name Meaning“Lizard of Amarga”
EraMesozoic – Early Cretaceous
ClassificationDinosauria, Saurischia, Sauropoda
Height2.5 meters (8.2 feet)
Length9 to 13 meters (30 to 43 feet)
Weight2.6 to 4 tons (5700 to 8800 lbs)
LocationArgentina (South America)

Amargasaurus was one of the most bizarre sauropod dinosaurs ever discovered. 

This is partly due to its unusually small size for a sauropod and also because of the double rows of tall spines arranged along its neck and back. 

This is a feature not seen in any other sauropod dinosaur ever discovered. 

Some experts think the spines may have a keratinous sheet or sail-like skin useful for display, combat, or defense against predators. 

Amargasaurus grew to a length of about nine to 13 meters (30–43 feet).

While it was a big dinosaur, this length was unusually small for a sauropod dinosaur. 

12. Stygimoloch

strangest dinosaurs
Stygimoloch Dinosaur on white background | Kitti Kahotong via iStock
Name Meaning“The Styx Demon”
EraMesozoic – Late Cretaceous
ClassificationDinosauria,‭ Ornithischia & Theropoda
Height1 meter (3 feet)
Length2.5 to 3 meters (8 to 10 feet)
Weight200 to 400 kg (440 to 880 lbs)
LocationUSA (North America)

The full name of this dinosaur translates as “horned demon from the river of death.”

This strange name refers to the bizarre appearance of this dinosaur’s skull, characterized by a bizarre array of bony knobs and spikes. 

Stygimoloch was a pachycephalosaurid, which means it had a hard skull that helped to protect its brain. 

This skull structure suggests that they engaged in head-butting behavior for a right to mate with the females, while the spikes and horns were probably for display. 

The function of the head adornment, as well as the true identity of this dinosaur, is still a subject of scientific debate, with some scientists suggesting that it may have been a juvenile Pachycephalosaurus.

11. Gigantoraptor

Life restoration of the giant Late Cretaceous Gigantoraptor erlianensis
Life restoration of the giant Late Cretaceous Gigantoraptor erlianensis -PaleoNeolitic – License
Name Meaning“Gigantic plunderer”
EraMesozoic – Late Cretaceous
ClassificationDinosauria, Saurischia, Theropoda
Height5–6 meters (16–20 feet) 
Length8 meters (26 feet) 
Weight1.5–2 tons (3,300–4,400 pounds)
LocationChina and Mongolia (China)

Only one part of this dinosaur’s name is accurate. 

The Gigantoraptor was truly gigantic, but it wasn’t really a raptor (contrary to what the name suggests). 

This means it was not a member of the dromaeosaurid family of dinosaurs. 

Gigantoraptor was an oviraptorosaur (a relative of the famous oviraptor) and is considered the largest known dinosaur in the group.

Like other feathered dinosaurs, the Gigantoraptor brooded on its eggs like many birds do today. 

However, due to their massive size, the eggs were arranged around the edges of the nest instead of the edge to keep the massive dinosaur from crushing them. 

10. Spinosaurus

Spinosaurus dinosaur on white background | Kitti Kahotong via iStock
Name Meaning“Spined lizard”
EraMesozoic – Cretaceous Period
ClassificationDinosauria, ‬Saurischia & Theropoda
Height4 to 5 meters (13 to 16 feet)
Length12 to 18 meters (39 to 59 feet)
Weight6 to 12 tons (13,000 to 26,000 pounds)

The Spinosaurus is currently the record holder for the longest meat-eating dinosaur (even bigger than the famous Tyrannosaurus rex). 

But the Spinosaurus wasn’t exactly like other theropods. 

It had a long crocodilian snout lined with straight, non-serrated teeth, which was unusual for a theropod. 

It also had long neural spines that may have supported a giant sail-like structure or a large hump of fat. 

Spinosaurus was a semi-aquatic dinosaur, and it preyed mainly on fish but was also capable of killing terrestrial prey. 

9. Concavenator

Concavenator was a carnivorous theropod dinosaur that lived in Spain during the Cretaceous Period.
Concavenator was a carnivorous theropod dinosaur that lived in Spain during the Cretaceous Period | CoreyFord via iStock
Name Meaning“Cuenca hunter with a hump”
EraMesozoic — Cretaceous
ClassificationDinosauria, ‬Saurischia & Theropoda
Height2 meters (6.6 feet)
Length5–6 meters (16–20 feet)
Weight320–400 kilograms (710–880 pounds)
LocationSpain (Europe)

The name Concavenator translates as “hunchback hunter from Cuenca.”

It refers to the region of Spain where this dinosaur lived (Cuenca) and also one of the most bizarre features that it had—a prominent hump on its back. 

Although there were many dinosaurs with humps or sails on their back, the Concavenator was unique because of the position of the hump, just in front of its hip. 

It was formed by two tall vertebrae that formed a narrow and pointed crest. 

While the purpose of this hump remains a subject of speculation, it’s one of the most notable features of this strange theropod.

8. Einiosaurus

Einiosaurus dinosaur drinking in the desert by day | Elenarts108 via iStock
Name Meaning“Bison lizard”
EraMesozoic — Cretaceous
ClassificationDinosauria, Ornithischia, Ceratopsia
Height2 meters (6.6 feet)
Length4.5 meters (15 feet)
Weight1.3 tons (2800 pounds)
LocationUSA (North America)

Einiosaurus was just like your typical ceratopsid dinosaur. 

It had a prominent neck frill with spikes along the edges and small brow horns similar to those of its relative in the centrosaurine subfamily. 

Where the Einiosaurus differed from everybody else was its peculiar, forward-curving nasal horns that looked like a bottle opener instead of the straight or slightly curved horns of other related dinosaurs. 

They lived in herds similar to that of modern bison, which is why the dinosaur’s name translates as bison lizard. 

Einiosaurus was a specialized herbivore with a dental battery that was effective for processing tough plant materials. 

7. Euoplocephalus 

Euoplocephalus from the Cretaceous era 3D illustration - Warpaintcobra via Istock
Euoplocephalus from the Cretaceous era 3D illustration – Warpaintcobra via Istock
Name Meaning“Well-armored head”
EraMesozoic – Late Cretaceous
ClassificationDinosauria, Ornithischia & Ankylosauria
Height2.5 meters (8 feet)
Length5.3 meters (17 feet) 
Weight2 metric tons (4,409.25 lbs)
LocationNorth America (Canada and the United States)

Euoplocephalus is one of the most heavily armored dinosaurs ever discovered. 

It was an ankylosaurid dinosaur, which means many of its relatives were armored as well. 

But the Euoplocephalus was unique because the bony plates and spikes that covered its body also covered parts of the face, forming a protective shield over its head. 

It was essentially an armored tank in dino-form. 

To complete this dinosaur’s bizarre suit of armor, it had a giant club on its tail, heavy enough to deal a devastating blow to any attacker. 

6. Chilesaurus

Chilesaurus Dinosaur on white background
Chilesaurus Dinosaur on white background | Kitti Kahotong via iStock
Name Meaning“Chile lizard”
EraMesozoic — Jurassic
ClassificationDinosauria, Saurischia, Theropoda
Height0.8 meters (2.8 feet)
Length3.2 meters (10.5 feet)
Weight136 kilograms (300 pounds)
LocationChile (South America)

The Chilesaurus was a truly bizarre dinosaur that looked like a poorly-assembled Lego puzzle. 

It was a theropod, which means it is distantly related to typical meat-eating dinosaurs like the Tyrannosaurus

Yet, this dinosaur’s spatula-shaped teeth suggest that it was a herbivore instead of a carnivore like its relatives.  

The pelvic arrangement of this dinosaur looked more like that of the ornithischian dinosaurs, while its feet were similar to that of a sauropod. 

This unique mix of traits makes the Chilesaurus an anomaly from an evolutionary perspective. 

5. Xixianykus

Xixianykus | Matt Van Rooijen via Wikiwand
Name Meaning“‬Xixian claw”
EraMesozoic — Cretaceous
ClassificationDinosauria, Sauruschia, Theropoda
Height20 centimeters (7.9 inches)
Length50 centimeters (20 inches)
Weight0.44 kilograms (1 pound)
LocationChina (Asia)

Xixianykus was a small feathered dinosaur only about 50 centimeters (20 inches) long. 

In fact, it is one of the smallest non-avian dinosaurs ever discovered, but it is still one of the most unusual dinosaurs ever due to the length of its legs. 

Xixianykus had the longest leg-to-body ratio of all known dinosaurs, with a height of about 20 centimeters (7.9 inches). 

Having extremely long legs like this meant this dinosaur was most likely an exceptionally fast runner. 

This would have been useful for outpacing potential predators in its habitat. 

Xixianykus also had an incredibly long third finger, which it likely used for probing into tree bark or termite mounds to find insects.

4. Cryolophosaurus

3D rendering of a Cryolophosaurus - Vac1 via Istock
3D rendering of a Cryolophosaurus – Vac1 via Istock
Name Meaning“Frozen crested lizard”
EraMesozoic – Early Jurassic
ClassificationDinosauria,‭ Saurischia & Theropoda
Height2.3 meters (7.5 feet)
Length6-7 meters (19.6-22.9 feet)
Weight350-465 kilograms (772-1,025 lbs)

Cryolophosaurus was a theropod dinosaur that lived during the Early Jurassic Period in present-day Antarctica. 

Discovered and named officially in 1991, this dinosaur was the first non-avian dinosaur discovered in Antarctica and one of the few carnivorous dinosaurs known from the continent so far. 

Cryolophosaurus was a large theropod with a subadult size of about six to seven meters (20–23 feet). 

But the most unusual feature of this dinosaur had to be the distinctive Elvis Presley-like crest on its head.

The unique “pompadour” appearance of this dinosaur’s crest has earned it the nickname “Elvisaurus.”

Although there are other theropods with distinctive cranial crests, the Cryolophosaurus is the only dinosaur whose crest runs across the skull this way. 

3. Oryctodromeus

Oryctodromeus | NaturalWorldLover via Nature Rules Fandom
Name Meaning“Digging runner”
EraMesozoic – Late Cretaceous
ClassificationDinosauria,‭ ‬Ornithischia,‭ Ornithopoda
Height2–3 feet (0.6 to 0.9 meters) 
Length6–9 feet (1.8 to 2.7 meters)
Weight22–32 kilograms (50–70 pounds)
LocationUSA (North America)

When you think of dinosaurs, the last thing on your mind is an animal that lives in burrows like a rodent. 

Yet, a few dinosaurs exhibited this behavior. 

The Oryctodromeus is a good example of a burrowing dinosaur. 

It was the first non-avian dinosaur known to have lived in burrows. 

This theropod was alive during the Cretaceous Period about 95 million years ago. 

Fossils of three Oryctodromeus individuals were found at the bottom of a six-and-a-half-foot burrow. 

The individuals were of different ages, suggesting that it was a mother with her young. 

The burrow would have protected this dinosaur against predators and also served as a lair for raising its young. 

2. Kosmoceratops

The Kosmoceratops
The Kosmoceratops – Nobu Tamura – License
Name Meaning“Ornate horned face”
EraMesozoic – Late Cretaceous
ClassificationDinosauria, ‬Ornithischia, & Ceraptosia
Height1.8 to 2 meters (6–6.5 feet)
Length4.5 meters (14.7 feet)
Weight1.2 tons (2,645 lbs)
LocationNorth America

The fossil record has an abundance of horned dinosaurs, but arguably, the most bizarre of them is the Kosmoceratops

Kosmoceratops had two large horn cores oriented forward and to the side of their face like the horns of a bison. 

The frills of this dinosaur were also highly decorated with up to 15 horns and horn-like structures of different sizes. 

It is a worthy candidate for the dinosaur with the most horns, and the frill also stands out from that of its relatives because it curved downwards and was bizarrely segmented. 

1. Nigersaurus

Nigersaurus 3D illustration - Warpaintcobra via Istock
Nigersaurus 3D illustration – Warpaintcobra via Istock
Name Meaning“Niger Reptile”
EraMesozoic – Early Cretaceous
ClassificationDinosauria, Saurischia & Sauropoda
Height2–3 meters (6.5–10 feet)
Length9–12 meters (30–40 feet)
Weight1.9 – 4 metric tons (4,188–8,818 lbs)
LocationAfrica (Niger)

The Nigersaurus was a relatively small sauropod dinosaur about the same size as a modern elephant. 

It is most famous for its bizarre dentition, which includes more than 500 teeth arranged in rows in its wide mouth. 

Even more strange is the fact that these teeth got replaced rapidly as they got worn down (every 14 days).

Having rows of strong teeth allowed the dinosaur to chew its food efficiently.

The teeth were located close to the front of the unusually broad, straight-edged mouth of the Nigersaurus, further adding to the already bizarre appearance of this dinosaur. 


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Jerry Young is a self-proclaimed prehistoric animal nerd. He has been fascinated with these ancient creatures for as long as he can remember, and his passion for them continues to this day. With his extensive knowledge and love for prehistoric animals, he is the perfect fit for Gage Beasley Prehistoric.

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