15 Dinosaurs That Lived in Modern-Day Arizona

Leave a comment / / Updated on: 29th December 2023

Arizona is famous as the home of geological relics like the Grand Canyon and the Petrified Forest. 

These natural structures are testaments to the state’s fascinating geologic past dating back to several million years ago. 

Before becoming the dry and barren landscape that it is today, the region was once home to a large subtropical forest bursting with fresh foliage.

In this forest and other lush landscapes scattered all over the state lived different species of dinosaurs during the Jurassic and Cretaceous periods. 

So far, paleontologists have recovered numerous body fossils, dinosaur footprints, and other trace fossils from prehistoric giants that once wandered through the state’s forests, dunes, and deserts. 

In this article, we’ll explore 15 of the dinosaurs that once called Arizona home, discussing their most impressive traits and unique attributes. 

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15. Sonorasaurus

Sonosaurus | Dmitry Bogdanov via Wikipedia CC BY 3.0
Name Meaning“Sonora lizard”
EraMesozoicEarly Cretaceous
ClassificationDinosauria, Saurischia & Theropoda
Height8 meters (26 feet)
Length15 meters (49 feet)
Weight35 tons (70,000 pounds)

Sonorasaurus was one of the largest dinosaurs to have lived in Arizona. 

It was a brachiosaurid sauropod, which means it is closely related to other giant sauropod dinosaurs like the famous Brachiosaurus

Sonorasaurus lived in Arizona from the Early Cretaceous to Late Cretaceous, between 112 and 93 million years ago. 

Sonorasaurus was named after the Sonora River, a large river that flows in Arizona’s Sonoran Desert, where fossils of this dinosaur were first found. 

It was about 15 meters (49 feet) long and stood at about eight meters (26 feet). 

This makes it about one-third the size of the giant Brachiosaurus

In April 2018, Sonorasaurus was declared the state dinosaur of Arizona, making it one of the most notable dinosaurs from the state. 

14. Segisaurus

Segisaurus | Jacksonwarrier via Dinopedia
Name Meaning“Tsegi Canyon Lizard”
EraMesozoic – Jurassic
ClassificationDinosauria, Saurischia & Theropoda
Height0.5 meters (1.65 feet)
Length1 meter (3.3 feet)
Weight4–7 kilograms. (8.8–15 lbs)

Segisaurus was a primitive theropod dinosaur that lived during the Jurassic Period, about 183 million years ago. 

This bipedal dinosaur had a bird-like body structure, with a stout body and elongated neck. 

Segisaurus was relatively small. 

It was only about one meter (3.3 feet) long and half a meter tall (1.65 feet) tall. 

The small size of this carnivorous dinosaur meant it only hunted small prey such as insects and lizards. 

Experts also think the Segisaurus may have been a scavenger. 

Segisaurus was named after the Tsegi Canyon, which is a part of the famous Navajo Sandstone Formation in Arizona. 

13. Sarahsaurus

Sarahsaurus | Brian Engh via Wikipedia CC BY 2.5
Name Meaning“Sarah’s lizard”
EraMesozoic – Early Jurassic
ClassificationDinosauria, Saurischia & Sauropodomorpha
Height1.2 meters (3.9 feet)
Length4.3‭ ‬meters (14 feet)
Weight200 kilograms (440 pounds)

Sarahsaurus is a member of a group of primitive dinosaurs known as the sauropodomorphs. 

These dinosaurs are considered the ancestors of the giant sauropods that would later dominate the planet during the Jurassic and Cretaceous periods. 

Sarahsaurus is one of the few members of this group that lived in North America. 

It lived in Northeastern Arizona during the Early Jurassic Period. 

The dinosaur’s name, which translates as Sarah’s lizard, honors Mrs Sarah Ernest Butler, the Austin philanthropist who helped fund the “Dino Pit” dinosaur exhibit.

Unlike the quadrupedal sauropods that evolved after them, Sarahsaurus and other sauropodomorphs were bipedal. 

They had short forelimbs, which were equipped with grasping hands for holding and manipulating the plant materials they fed on. 

12. Chindesaurus

Chinderaurus | Jeff Martz via Wikipedia Public Domain
Name Meaning“Chinde Point Lizard”
EraMesozoic – Late Triassic
ClassificationDinosauria, Saurischia & Herrerasauria
Height1 meter (3.3 feet)
Length2–4 meters (6.6–13.1 feet)
Weight23–45 kilograms (50–100 pounds)

Chindesaurus was a primitive saurischian dinosaur that lived in the Southwestern United States during the Late Triassic Period

This makes it one of the oldest dinosaurs known from Arizona. 

When the first Chindesaurus fossil was discovered in 1984, it was nicknamed “Gertie” after Gertie, the dinosaur from the 1914 animated short film. 

Fossils of this dinosaur were discovered in the famous Petrified National Park in Arizona. 

Chindesaurus was a medium-sized bipedal dinosaur about the same size as a wolf. 

Due to the primitive age of this dinosaur and the fragmented nature of the fossils discovered so far, scientists are not entirely certain of its classification. 

11. Acrocanthosaurus

Acrocanthosaurus | Kitti Kahotong via iStock
Name Meaning“High-spined lizard”
EraMesozoicEarly Cretaceous
ClassificationDinosauria, Saurischia & Theropoda
Height4.8 meters (16 feet)
Length11–11.5 meters (36–38 feet)
Weight4.4-6.6 tons (8,800–13,200 pounds)

Arizona had an abundance of large predator dinosaurs during the Mesozoic, and the Acrocanthosaurus was one of them. 

It lived during the Early Cretaceous, long before more famous theropod dinosaurs like the T-rex became prominent. 

Acrocanthosaurus lived between 113 and 110 million years ago. 

Although fossils of this dinosaur were found mainly in Oklahoma, the dinosaur’s range probably covered southern Arizona as well. 

Standing at a height of up to 1.2 meters (4 feet) and a length of over 11 meters (36 feet), Acrocanthosaurus was one of the largest theropod dinosaurs to have ever lived. 

The dinosaur’s name translates as “high-spined lizard,” a reference to the notably high neural spines on its back. 

10. Camposaurus 

Camposaurus | Warpaintcobra via iStock
Name Meaning“Camp’s lizard”
EraMesozoic – Late Triassic
ClassificationDinosauria, Saurischia & Neotheropoda

Camposaurus was a primitive theropod dinosaur named after famous paleontologist Charles Lewis Camp. 

The specific name Camposaurus arizonensis‭ references the fact that this dinosaur lived in Arizona several million years ago. 

Camposaurus lived during the Late Triassic Period. 

This makes it one of the oldest (possibly the oldest) neotheropod dinosaurs ever discovered. 

Camposaurus is very similar in appearance to the famous Coelophysis, another of Arizona’s famous dinosaurs. 

It was relatively small and lightweight, but its exact height and length are not known due to the fragmentary nature of its fossils. 

9. Scutellosaurus

Scutellosaurus| CoreyFord via iStock
Name Meaning“Little shielded lizard‭”
EraMesozoic – Jurassic 
ClassificationDinosauria, Ornithischia, &‭ ‬Thyreophora
Height50 centimeters (20 inches)
Length1.2 meters (3.9 feet)
Weight10 kilograms (22 pounds)

Scutellosaurus was an armored dinosaur that lived in Arizona during the Jurassic Period about 196 million years ago. 

It is regarded as one of the most famous armored dinosaurs to have ever lived. 

It is considered an ancestor of giant armored dinosaurs like the Stegosaurus and Ankylosaurus.

Members of this group are collectively classified as ‬thyreophoran dinosaurs.

Scutellosaurus was relatively small, but it had a covering of flexible but tough armored scutes arranged along its back, which protected predators. 

The dinosaur’s name, which translates as “little armored lizard,” is a reference to this unique appearance. 

Although it had four developed limbs that would have supported a quadrupedal stance, the Scutellosaurus was likely bipedal, meaning it walked on only its hindlimbs. 

8. Zuniceratops

Zuniceratops | Warpaintcobra via iStock
Name Meaning“Zuni’s horned face”
EraMesozoic – Late Jurassic
ClassificationDinosauria, Ornithischia, & Ceratopsia
Height1 meter (3.3 feet) 
Length2.2 meters (7.2 feet) 
Weight175 kilograms (386 pounds)

Zuniceratops is one of the dinosaurs discovered in the Zuni Basin, located along the Arizona/New Mexico Border. 

This suggests that the dinosaur’s range probably covered both states. 

The name Zuniceratops translates as Zuni’s horned face, referencing the dinosaur’s identity as a ceratopsian dinosaur. 

The ceratopsians are known for their prominent facial horns and large frills. 

Zuniceratops is an important member of this because it shows traits seen in both primitive ceratopsians (Protoceratops) and actual ceratopsians.  

It is the oldest dinosaur with a brow horn but doesn’t have nasal horns like the ceratopsian dinosaurs that evolved later. 

7. Crittendenceratops

Crittendenceratops | PaleoEquii via Wikipedia CC BY-SA 4.0
Name Meaning“‬Fort Crittenden Formation horned face‭”
EraMesozoic – Late Jurassic
ClassificationDinosauria, Ornithischia, & Ceratopsia
Length3.3 meters (11 feet) 
Weight0.75 tons (1,653 pounds)

Crittendenceratops is a recently-discovered ceratopsian dinosaur named after Arizona’s Fort Crittenden Formation where its first (and only) fossil so far was found. 

It is the first dinosaur to be formally named from this formation. 

This 73-million-year-old dinosaur lived during the Late Cretaceous Period. 

It belongs to a group known as the ceratopsid dinosaurs, characterized by prominent neck frills and facial horns. 

The dinosaur was characterized by a single forward-curving horn that had a hook-like appearance and was positioned at the center of its skull. 

This herbivorous dinosaur was relatively small compared to other ceratopsids. 

It was about 11 feet long and weighed less than a ton. 

6. Megapnosaurus 

Megapnosaurus | UnexpectedDinoLesson via Wikipedia CC BY-SA 4.0
Name Meaning“Big dead lizard‭”
EraMesozoic – Jurassic 
ClassificationDinosauria, Saurischia & Theropoda
Length2.2 meters (7.2 feet)
Weight13 kilograms (29 pounds)

Megapnosaurus was a theropod dinosaur that lived in parts of Africa and North America during the Jurassic Period (about 188 million years ago). 

Originally named Syntarsus by the scientist who discovered it in 1969, the dinosaur was renamed Megapnosaurus in 2001 because the previous name was already assigned to a beetle. 

Megapnosaurus is similar in appearance to the Coelophysis, so much so that some scientists think both dinosaurs are probably the same. 

Although it is notably from Africa, fossils believed to be the Megapnosaurus have been identified from Arizona’s Kenyatta Formation. 

The widespread distribution of this Megapnosaurus in North America and Africa suggests that both continents were connected when the dinosaur was alive. 

5. Apatosaurus 

Apatosaurus | Elenarts108 via iStock
Name Meaning“Deceptive Lizard”
EraMesozoic – Late Jurassic 
ClassificationDinosauria, Saurischia & Sauropoda
HeightAround 7–9 meters (23–30 feet) at the hips
Length21–23 meters (69–75 feet)
Weight16.4–22.4 tons (36,000–49,000 pounds)

Apatosaurus is a member of a group of dinosaurs known as the diplodocid sauropods. 

This is a group of primitive sauropods that includes some of the longest sauropods to have ever lived. 

Apatosaurus is similar in appearance to the famous Diplodocus but has a slightly stockier build. 

The quadrupedal dinosaur had a robust body, a long neck, and a long, whip-like tail.

Apatosaurus was up to 80 feet long dinosaur and weighed over 20 tons on average. 

It lived in parts of Western North America about 150 million years ago. 

This dinosaur has been confused with other giant sauropod dinosaurs like the Camarasurus and Brachiosaurus due to the similarities in their appearance. 

4. Nothronychus 

Nothronychus | PaleoNeolitic via Wikipedia CC BY 4.0
Name Meaning‬”Slothful claw”
EraMesozoic – Cretaceous 
ClassificationDinosauria, Saurischia & Theropoda
Height3.4 meters (12 feet)
Length4.2–5.3 meters (14–17 feet)
Weight800–1,200 kilograms (1,800–2,600 pounds)

Nothronychus was an odd-looking dinosaur whose fossils were discovered in the Zuni Basin, located on the border of New Mexico and Arizona. 

This robust theropod dinosaur was characterized by stocky hindlimbs and relatively long arms. 

It also had dexterous hands with long, sharply-pointed claws that looked like a sloth’s hands. 

The dinosaur’s name, which translates as “slothful claw,” refers to these large 12-inch-long claws. 

Nothronychus also had a large pot belly and an extremely long neck. 

Two slightly different species of this 92 million-year-old dinosaur have been discovered so far. 

Nothronychus was a herbivore, with its robust claws serving the purpose of holding and manipulating the plants it ate. 

3. Tyrannosaurus rex

Tyrannosaurus rex | digitalgenetics via iStock
Name Meaning“Tyrant lizard”
EraMesozoic – Late Triassic 
ClassificationDinosauria, Saurischia & Theropoda
Height3.7–4 meters (12–13 feet)
Length12–13 meters (40–42 feet)
Weight8 tons (17,600 pounds)

The iconic T-rex ruled most of western North America during the Cretaceous, and its range included parts of Arizona. 

This theropod dinosaur was the region’s top predator and the largest carnivore in that part of the continent during the Cretaceous Period, between 68 and 66 million years ago.  

The T-rex was a bipedal carnivore famous for its phony forelimbs that were extremely small compared to the rest of its body. 

While it is often regarded as one of the most prolific predators to have ever lived, experts think the T-rex may have been a scavenger, too, using its size to bully and steal prey from smaller dinosaurs. 

The Tyrannosaurus stood at a height of about 12 to 13 meters (40 to 42 feet) and weighed up to eight tons on average. 

2. Dilophosaurus

Dilophosaurus | dottedhippo via iStock
Name Meaning“Double-crested Lizard”
EraMesozoic – Early Jurassic
ClassificationDinosauria, Saurischia & Theropoda
Height2 meters (6.5 feet)
Length6–7 meters (20–23 feet)
Weight400 kilograms (880 pounds)

Famous as the fictionalized, frilled, venom-spitting dinosaur from the Jurassic Park movies, the real Dilophosaurus lived in Northern Arizona during the Early Jurassic Period about 186 million years ago. 

Contrary to its depiction in the movies, Dilophosaurus did not have a frill and couldn’t spit venom. 

It did have a pair of arched crests on its skull. 

The dinosaur’s name, which translates as “two-crested lizard,” is a reference to this double crest.

Dilophosaurus was a medium-sized carnivorous dinosaur. 

It was up to seven meters (23 feet) long and weighed about 400 kilograms (880 pounds). 

Dilophosaurus was the largest meat-eating dinosaur of its time and was one of the biggest land animals in North America during the Jurassic Period. 

Unlike the other giant theropods that evolved later, Dilophosaurus was an agile dinosaur with a slender build. 

1. Coelophysis 

Coelophysis | Vac1 via iStock
Name Meaning“Hollow form‭”
EraMesozoic – Early Jurassic
ClassificationDinosauria, Saurischia & Theropoda
Height1 meter (3.3 feet)
Length3 meters (9.8 feet)
Weight15 kilograms (33 pounds)

Coelophysis is one of the most popular dinosaurs native to Arizona. 

The popularity of this dinosaur is due to its status as one of the oldest dinosaurs ever discovered. 

Coelophysis lived during the Early Jurassic Period, about 215 to 208.5 million years ago. 

It was a small bipedal dinosaur with an average length of about three meters (9.8 feet). 

The slender build of this dinosaur suggests that it was an agile runner. 

Coelophysis had a narrow head with an elongated snout. 

The snout was lined with numerous serrated blade-like teeth, suggesting a carnivorous diet. 

It probably preyed on small prey animals such as lizards. 

Apart from Arizona, numerous fossils of this dinosaur have been found in various parts of the world. 


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