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Scariest Dinosaurs North America: What Makes Them Scary?

What were the Scariest Dinosaurs North America? Dinosaurs, in general, are scary. Well, who wouldn’t be scared of them? These dinosaurs are bigger than anyone else’s, they weigh much heavier, they have body parts that can kill people had they lived in the same era as these beasts, and some of them are very clever and smart. No one would stand a chance in surviving these beasts. However, some dinosaurs were indeed scary due to their build, intelligence levels, or a combination of both.

Nothing brings out fear more than sharp huge teeth that are coming towards you! The T. Rex had some of the largest teeth, all adapted for biting and tearing – definitely scary – AdventureDinosaurs

What Are The Scariest Dinosaurs North America?

The Allosaurus, the Argentinosaurus, Diplodocus, the Tyrannosaurus Rex, the Ankylosaurus, the Stegosaurs, and the Troodon are known to be the scariest dinosaurs in North America. They are known for their build, intelligence, and other abilities.

This article will discuss the things why dinosaurs are scary and what made them look scary. This article will also talk about the scariest herbivores and carnivores among the many species of dinosaurs that roamed the expanse of North America. 

Finally, I’ll describe some of the scariest dinosaurs-herbivores and carnivores – that lived in North America.

What Makes A Dinosaur Scary: A Closer Look On Its Anatomy

One of the reasons why we think dinosaurs are scary is because of their build. We will take a closer look at what normal dinosaur anatomy consists of.

Scary Teeth With A Deeper Purpose

It can come as a scary sight to see a Tyrannosaurus rex grinning in front of you, its massive and sharp teeth on full display. Even though they are scary, those huge teeth served a very important purpose for dinosaurs and how they lived.

Scientists can glean a lot of information by checking the teeth of a specific dinosaur, such as what it ate, how it ate, and how it managed to fit in with the other dinosaurs and animals in the ecosystem. 

Just by checking the teeth of a dinosaur, you can easily determine how they lived their lives while still roaming the wide expanse of the Earth.

One amazing fact to remember is that dinosaurs do not have the same set of teeth from the moment they’re born down to their last days on Earth. 

A single dinosaur changes teeth throughout their lifetimes, with some species going through a thousand sets of teeth throughout their lives.

It is a continuous process, and the crowns are shed, other teeth take their designated spots, and the root of the teeth gets absorbed. It is the reason why dissociated dinosaur teeth without crowns are very much prevalent in fossil records.

Teeth are usually worn out due to eating, which often shows how dinosaurs’ diet was when they were still alive.

Claws That Are Not For Decoration

Deinonychus is a dinosaur that means terrible claws, according to their literal Greek translations. It refers to the large, single, and curving claws found on each specific dinosaur’s hind fit. 

It is a diagnostic trait shared with its fellow raptors during the middle to the late Cretaceous period.

This dinosaur is an example of how claws are used as a weapon for their benefit and survival. This dinosaur was seen to be related to birds because it was allegedly covered with feathers as well. (Source)

Dinosaurs were known to use their claws as a way for them to defend themselves from other species. It is used to hurt other dinosaur species, especially when they are tearing each other away.

It is also used for gathering food, such as their prey. They use their sharp and huge claws to hurt and subdue their prey, therefore allowing them to be fed to them as they please.

Scary Horns With An Interesting Purpose

Dinosaurs with horns are called ceratopsians or called “horned-face” dinosaurs. Some of the known ceratopsians include Triceratops, which is known for its three horns.

Contrary to popular belief, dinosaurs used their horns as weapons similar to their claws or teeth. Interestingly enough, ceratopsian horns are probably used to recognize their species and compete for mating processes.

Adult male ceratopsians are known to lock horns with females for mating and procreation. In addition, it is said that the horned dinosaurs used their horns to attract females as a seducing tactic for them to procreate and produce offspring. (Source)

The Scariest Dinosaurs in North America

Of course, some dinosaurs existed in North America. These dinosaurs are known to be the scariest in their groups, and no one dared to mess with them.

The Scariest Herbivores

Even though they were herbivores, these dinosaurs are known to be of large build and scary appearances. They are also equipped with sharp teeth, claws, and a powerful body and tail. Some of these dinosaurs include Diplodocus, the stegosaurus, the famous Triceratops, and the Ankylosaurus.

A stegosaurus differs from other dinosaurs due to its spiked tail and large plates on its back. The latter feature is known to be their weapon against predators.

Triceratops also use their horns for defense. The Ankylosaurus is also known for its resemblance to modern-day armadillos, spines, and spikes covering its sides and back. It is also used as a form of defense against their predators.

Ankylosaurus is also known for their mace. They have a dense bone, which they usually use as a weapon to bludgeon the predator threatening them. A swing from the Ankylosaurus can easily break the legs of a theropod.

Diplodocus and Argentinosaurus: The Scariest Herbivores

These giant sauropods are difficult to kill, even by dinosaur standards. Diplodocus and Argentinosaurus are extremely big in size and proportion, so it would be a very hard task to kill a full-grown adult Argentinosaurus.

The Argentinosaurus holds the record for the longest and largest dinosaur that ever existed and the largest land animal that ever graced the face of the Earth. Argentinosaurus is estimated to be about 130 feet long (or 40 meters) and weighs up to 100 tons. A full-grown Argentinosaurus would be very hard to kill, so the biggest predators will not even touch them. (Source)

Scariest Armored Dinosaurs and Other Scary Dinosaurs

Armored dinosaurs are scarier because they have specific weapons and armor to protect themselves and their babies, especially when predators threaten them. Examples of armored dinosaurs include the Stegosaurus and the Ankylosaurus.

Meanwhile, the Utahraptor is the biggest known raptor, and it weighed about a ton. It was much bigger than Velociraptors, but they are much slower. However, what made them the scariest dinosaur ever is that it is equipped with a group of sickle-shaped claws, each is razor-sharp and nearly 10 inches long. They were known to use their claws in killing their predators and hunting down their prey.

Three Of The Scariest North American Dinosaurs

We will be giving a closer look at the three of the scariest dinosaurs that roamed the huge swaths of land in North America.

The Allosaurus: Most Famous Carnivore After The T.Rex

Allosaurus is known to be the top predator of the Late Jurassic North America. It is known to be one of the scariest carnivores and one of the scariest dinosaurs ever to grace the planet.

Allosaurus teeth were similar to a crocodile’s, and they shed and replace their teeth faster than any other dinosaur. An Allosaurus weighed around two tons and grew to 10.5 meters or 35 feet in length. Some fossils, however, indicated that they must have grown longer, reaching 12 meters. (Source)

It has forelimbs, which are smaller than the other dinosaurs but not as small as those of the T.Rex. They probably used their forelimbs and sharp claws for grasping their food and pushing the predators away.

The Troodon: A Mix Of Smart And Scary

This dinosaur was discovered in Montana and is considered one of the smartest dinosaurs that ever existed. It is mainly attributed to its brain size, which was much bigger than other dinosaurs. That’s not to lessen the shape and sharpness of the Troodon teeth, which were also adapted for eating meat. Sharp, serrated and deadly effective if it bit into prey. (Source)

Some scientists even think that it had the same level of intelligence as that of a modern-day bird. This dinosaur was also known as a carnivore, though some scientists think it also ate plants, making it an omnivore.

A single Troodon might not be enough to scare a predator, but a group of Troodon would be enough to make you rethink attacking them. Their advantage is also related to their brain, which makes them think of your next moves before attacking them. Its scary brainpower makes it a smart yet scary dinosaur that existed in North America.

The Tyrannosaurus Rex: The King of Predators

It was known to be the ultimate king of the dinosaurs when it existed back then. It was robustly built and thinking the T. Rex could not defeat it would be a stupid move on any dinosaur or animal living on Earth back then. Tyrannosaurus rex can easily outweigh dinosaurs such as the Giganotosaurus because of its wits.

They also had extraordinary smelling abilities, making them a formidable force to be reckoned with aside from their sheer strength and build. They were known as smart predators, which are almost as smart as the raptors.


Dinosaurs are indeed scary beasts, and these were supported by the existing records about their stunning anatomical features. Nowadays, having these kinds of features would consider someone a really scary creature, such as huge horns, gigantic teeth, and intensely sharp claws. Many of the scariest dinosaurs in North America are the ones we know today, attributed to their skill, wit, and sometimes a combination of both.

● I’ve written a whole article listing 13 of the most terrifying dinosaurs and took it one step further by asking you to imagine this scenario of being chased by the dinosaur.

● If you are interested in reading more about carnivorous dinosaurs, I wrote an article analyzing which dinosaur was the best hunter which includes why T. Rex is known as the king of dinosaurs.