Which Animals Today Were Alive at the Same Time as Dinosaurs?

Written by Emmanuel Kingsley
Published: December 20, 2022
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Despite still being in existence, some animals are older than we realize. In other words, some animal species have been in existence for millions of years, some as far back as when dinosaurs still roamed the earth. However, they might not have looked the same as they do now; many of their current features might have developed as part of their evolution process to help them adapt to their new environments. This article discusses some animals today that were alive during the time of dinosaurs. 

When Did Dinosaurs Exist?

Masiakasaurus 3D render

Dinosaurs lived around 240 million years ago.


Dinosaurs are a large, extinct group of reptiles that lived roughly 240 million years ago during the Triassic Period. All dinosaurs were vertebrates with textured skin. They were divided into avian dinosaurs and non-avian dinosaurs – avians meaning those that had wings and could fly, and non-avian for those that could not. There were further different classifications of these animals based on size, diet, and habitat, and this wide disparity made it easy for them to survive on the earth, which still had all continents joined at the time. As the continents started to split, these animals experienced continental drifting until they finally mysteriously disappeared at the end of the Cretaceous Period, roughly 65 million years ago. Below are some animals that existed at the same time as these fearful reptiles:

1. Snakes 

Eastern tiger snake- side view

Snakes existed alongside dinosaurs as early as 167 million years ago.

©SunofErat_Matt_CCBY2.0 – License

Snakes are among the animals that existed at the same time as dinosaurs. However, the snakes that existed at the time were a little different from the ones that exist now. Snakes are generally either venomous or nonvenomous. Although they have a reputation for being “deadly” and “threatening,” there are over 3,500 recognized snake species worldwide, with just 10 to 15% of them being venomous and 85% non-venomous.

Despite being one of the most popular reptiles, there is no precise known date marking the existence of snakes. Although they are reptiles, numerous ideas and research postulate the possibility of their having more peculiar origins and evolution. The Paleocene Epoch, which lasted from 66 million to 56 million years ago, is when experts first believed the earliest snakes in history were first discovered. However, further research proved that snakes actually predated 66 million years ago in terms of their genesis, but most of their evolution happened during the Paleocene Epoch.

The oldest snakes have only recently been discovered, dating back to 167 million years when snakes were thought to have had legs. Although whether or not they had legs is still a mystery, it has been proven that these snakes existed alongside dinosaurs as early as 167 million years ago. However, these snakes were fundamentally different from the ones that exist currently. Fossils show that some of these ancient snakes had more flexible jaws and distinctive teeth. Some of these old snakes include the Eophis Underwoodi and the Portugalophis Lignites.

2. Alligators

Head-on view of large alligator

Alligators that existed millions of years ago are not so much different from the ones that exist today.


Alligators are enormous reptiles that belong to the same family as crocodiles, but they are only found natively in China and the southern United States. Even though alligators are members of the same group as dinosaurs, they are not dinosaurs. Their predecessors coexisted on earth with dinosaurs at the same time and were closely connected to them. Unlike some animals that went through evolutionary processes to be able to fit into new habitats or embrace new diets, alligators that existed millions of years ago are not so much different from the ones that exist today. In other words, alligators in this contemporary day are essentially identical to those in the Cretaceous period (about 145 to 66 million years ago).

Unlike dinosaurs, alligators survived extinction for reasons that are not particularly clear to experts. The alligator is a member of the order Crocodilia, which also contains crocodiles, and these two animals are some of the species under this order that have not undergone much evolution. Like modern-day alligators, alligators that existed alongside dinosaurs had similar predatory features, such as waiting for their prey to get close enough before they attacked. Their eyes, like those of modern crocodilians, were located on top of their heads, which allowed them to observe their prey even when the rest of their body was submerged.

3. Sea Turtles

Sea turtle attacked by tiger shark

Although their exact ancestors are unknown, turtles emerged 230 million years ago, primarily during the Triassic Period.


Another animal on the list of animals that existed at the same time as dinosaurs is the sea turtle. As the name implies, these are turtles that can only survive in water. With the exception of the most severe polar locations, these turtles may be found in practically every marine ecosystem on the planet. Like dinosaurs, sea turtles are reptiles, and although they are significantly smaller than dinosaurs, they existed at the same time as these prehistoric animals. Although their exact ancestors are unknown, turtles emerged 230 million years ago, primarily during the Triassic Period. Experts differ on whether turtles are related to the archosaurs, which include crocodiles, pterosaurs, dinosaurs, and birds, or whether they are more closely related to lizards and snakes.

The extinction event that took some dinosaurs off the planet also affected these sea turtles at the time, but they were not completely wiped out. The number of turtle species declined at the time and did not start to rise again until the Cretaceous period, which started 145 million years ago. Later down the line, the extinction event which completely wiped off dinosaurs happened, and although sea turtles were greatly affected, even more than the last time, they survived.

Despite the fact that these sea turtles lived at the same time as dinosaurs, it is believed that they predated the existence of dinosaurs. The earliest known fossil of a sea turtle was found during the Permian epoch’s latter stages, long before dinosaurs or any other living reptile species ever appeared. The evolution of turtles began at least 7 million years before that of any other living reptile. As a result, it is challenging to determine their place in the reptilian evolutionary tree.

Up Next: 

Did Humans Live With Dinosaurs?

How Long Were Dinosaurs on Earth?

9 Massive Prehistoric Animals that Lived Before Dinosaurs

Which Living Animals Are Closely Related to Dinosaurs Today?

The photo featured at the top of this post is © John Back/Shutterstock.com

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  1. , Available here: https://adventuredinosaurs.com/2021/08/28/what-animals-alive-today-lived-with-dinosaurs-15-surprising-species/
  2. Tracy V. Wilson, Available here: https://science.howstuffworks.com/environmental/earth/geology/dinosaur-contemporary.htm
  3. Nickie Latham, Available here: https://www.bbcearth.com/news/10-animals-with-pre-historic-roots