Believe it or not, there was a time that turtles and dinosaurs coexisted peacefully on earth. Paleontologists say that turtles and dinosaurs had shared natural habitats even before dinosaurs became extinct. Turtles are a reptile family that may be found on all continents except Antarctica. They include species living in salt and fresh water and those who live on lands, such as sea turtles, terrapins, and tortoises. Turtles have survived many devastating mass extinctions, including one that wiped off the dinosaurs, which have been around for tens of millions of years.
Did turtles live with dinosaurs? Yes. The earliest known records of sea turtles appearing on earth happened in the Jurassic period. Prehistoric turtles lived with dinosaurs until the dinosaurs became extinct 65 million years ago.
This article will discuss how old turtles are and how they came to coexist with dinosaurs here on earth. We will also discuss more on their relationships with the dinosaurs and where they differ from them. Lastly, we will compare and contrast the prehistoric turtles of yesterday to the turtles of today.
Did Turtles Exist Before Dinosaurs?
Scientists have claimed that dinosaurs existed with turtles. Here are some of the proof points they have given as evidence.
Turtles Roamed The Same Earth As Dinosaurs
Turtles evolved 230 million years ago, mostly during the Triassic Period, but their exact origins are unknown. Some experts believe turtles are more closely linked to lizards and snakes, while others feel they belong in the archosaurs, including crocodiles, pterosaurs, dinosaurs, and birds.
Turtles survived the Triassic Period’s great extinction, which wiped out enormous swaths of life and ushered in the dinosaur era. Turtle diversity was at an all-time low at the time. The numbers of turtle species did not begin to increase until the Cretaceous period, which began 145 million years ago. It stayed high until another catastrophic extinction, one of the most violent ever witnessed on the planet.
The Asteroid Has Greatly Benefitted The Turtles
The dinosaurs suffered greatly during the striking of this asteroid on earth, but it did not harm nor damage the turtles.
The dinosaurs and countless other species perished in this magnificent catastrophe, which was assumed to have been triggered by an asteroid crashing to earth. Still, turtles not only survived, but their diversity seemed to expand. Some turtle species did become extinct at this period, but many others did not. When compared to groups like dinosaurs or lizards, the number of species that remained is impressive.
There was a significant peak in the number of turtle genera over the next five million years. Water-dwelling animals were somewhat safe from whatever was killing the land vegetation and dinosaurs. In short, the turtles survived what caused the dinosaurs’ demise on earth.
How The Turtles Survived The Big One
A meteorite hit most certainly triggered the global extinction event that wiped out the dinosaurs, known as the K-T boundary, because of its unique mark in rock layers. However, the exact sequence of events is still questioned.
Some academics believe the sky was darkened by a series of world-shattering volcanic eruptions, which may or could not have been caused by the meteor. Like other burrowing and water-dwelling creatures, the turtles survived the dinosaur-killing whole-Earth mass extinction, which wiped out 90 percent of all land-dwelling animal and plant species, including land-dwelling turtles.
Small animals with a slow metabolism that live in the water, such as turtles, are thought to do well over the K-T barrier.
These turtles ate soft vegetation and crustaceans and resided in North American lakes and streams.
Though they aren’t closely linked to any surviving turtle species, they would have looked like today’s painted or cooter turtles.
They were part of a broad group of turtles known as baenids, of which at least eight survived the mass extinction only to perish subsequently due to other causes. (Source)
Are Turtles Part Of The Dinosaur Family?
Paleontologists connected turtles to dinosaurs for several reasons. Here are some of those reasons.
They Existed Together, But Not Closely Related
Some researchers have raised the question of turtles being related to the dinosaurs because they existed together until the mass extinction of dinosaurs happened. Thus, more and more people have questioned the placement of turtles in the reptilian phylogeny.
For various reasons, the place of turtles in the reptile phylogeny has always been a point of contention. Turtles are one of a kind among reptiles, thanks to their significantly modified body structures (e.g., shells) and the fact that they are anapsids.
The oldest turtle fossil was discovered in the declining years of the Permian epoch, before dinosaurs or any other extant reptile groups had ever emerged.
According to expert agreement, the archosaurs (which include dinosaurs, crocodilians, pterosaurs, and birds) are more closely related to turtles than the lepidosaurs, according to expert agreement (the lizards, snakes, tuatara, and mosasaurs).
Turtles’ evolution predates that of any other living reptiles by at least 7 million years. Thus it’s difficult to tell where they fit into the reptilian family tree.
One thing we have to remember, however, is that everything living on this earth is related to one another. Still, if we talk about close relations, then turtles are not as closely related to dinosaurs as other animals.
Reptiles are near as diversified as mammals in terms of species. The only problem with reptiles is that they are mostly gone, leaving only birds, turtles, lizards, snakes, tuataras, and crocodiles. The fact that something is reptile does not imply that it is linked to dinosaurs.
Why Some People Believe They Are Related
Turtles, which are thought to have existed for a long time, are among the simplest and most common reptiles on the planet today. According to scientists, turtles coexisted with dinosaurs roughly 110 million years ago until the K-Pg mass extinction, which wiped out the dinosaurs.
Archosaurs include crocodiles, dinosaurs that have died out, and pterosaurs, about animals with a hole between the eye socket and nostril. Turtles and these archosaurs had a common ancestry, according to a hypothesis supported by DNA evidence.
Another theory is that turtles are anapsids, or creatures with no side holes in their skulls, whereas dinosaurs are diapsids, creatures with skulls with two openings. It is crucial because diapsids are thought to have developed from anapsids.
Turtles are demonstrated to be connected to dinosaurs in both of these hypotheses. It is possible that turtles are descended from the same ancestor as dinosaurs or that dinosaurs are more advanced versions of the turtles’ forebears.(Source)
Comparing Ancient Turtles To Modern-Day Turtles
There is no doubt that ancient turtles and modern-day turtles are quite alike. Here are some of the contrasts and comparisons.
Turtles Have Evolved And Adapted To Its Environments
In some ways, turtle evolution is a simple story to follow: the fundamental turtle body design emerged early in the history of life, during the late Triassic period, and has remained mostly constant until now, with the normal changes in size, habitat, and adornment.
Like most other creatures, the evolutionary turtle tree contains many missing links, some of which have been located. In contrast, others have not, false starts and short-lived instances of gigantism.
Ancient turtles and tortoises were largely fixed into their contemporary body patterns by the early Jurassic period, around 200 million years ago, though there was still potential for innovation.
YouTube Video about the Evolution of Sea Turtles
Archelon and Protostega, two sea giants, measured about 10 feet long from head to tail and weighed around two tons, were the most famous turtles of the Cretaceous epoch.
As you might think, these massive turtles had broad, muscular front flippers to help drive their massive bodies through the water; their nearest living cousin is the considerably smaller Leatherback turtle, which weighs less than a ton. (Source)
Hard Shells That Transcended Evolutions
One of the most common similarities between ancient turtles and modern-day turtles is their hard shells.
Leatherbacks were known to have no shells covering their backs. While the leatherback’s ancient ancestors were diversifying, other stem turtle groups continued to refine an armored shell, eventually changing to a streamlined body plan with a robust and light plastron and carapace.
Apart from the leatherback, Ctenochelys acris, an 80 million-year-old species from the southern United States, is a potential ancestor of all modern-day sea turtles. It shares traits with both contemporary sea turtles and freshwater snapping turtles, such as huge back flippers that would have been utilized for propulsion, which modern sea turtles lack.
The Emergence Of The Shelled Turtles We Know Today
Around 40 million years ago, the first “real” shelled marine turtles appeared. Chelonian turtles are the name for these turtles, which means “shelled turtles.” They could resist formidable marine predators such as sharks, lepidosaurs, and eventually mammals thanks to this armor.
Six Chelonian species are still alive today, although practically every other form of sea turtle has become extinct. The turtles that arose during this period are extremely similar to those that exist now.
The Eocene-Oligocene Transition occurred approximately 34 million years ago when the earth transitioned from being quite warm to being fairly frigid, with the ice caps rebuilding.
At this time, the ancestor of modern green sea turtles, or the Chelonia mydas, was probably a generalist omnivore. Still, localized changes in climate impacted its food source, resulting in the evolution of specialized feeding techniques: algae-grazing green turtles and warm-blooded, sea cucumber-hunting flatback turtles, known as the Natator depressus.
Both of these turtles are functional omnivores, but their behavior dictates their diet. Although all four marine turtles are “officially” omnivores, they follow rather strict diets in practice. For crushing mollusks and shellfish, loggerhead turtles have sharp teeth and beaks.
Hawksbill turtles can survive nearly completely on sea sponges, while olive ridleys eat jellyfish, fish eggs, echinoderms, and shrimp. Although Kemp’s ridley turtles are the only true omnivore sea turtles, eating mollusks, jellyfish, fish, and seaweed, juveniles have specific adaptations for catching crabs.
The Turtles That We Know Today
In the last 3 million years, the earth’s form has shifted. The uplifting of Central America, which was previously fully submerged under the sea, cut off communities of turtles in the Pacific and Atlantic oceans. Additionally, as upwellings of cold current flow at the Cape of Good Hope and Tierra Del Fuego (South America’s southernmost tip) prevent many of these warm-blooded creatures from rounding the continents’ tips.
The worldwide sea turtle gene pool has been influenced by the isolation of the oceans, which was not far enough in the old days to cause speciation. We are witnessing the early phases of speciation in loggerhead turtles, as there are now numerous genetically different populations of loggerheads, most notably when comparing Pacific and Atlantic loggerheads.
Green turtles also take a similar pattern, which is more evident due to their more varied shell markings. Even though green turtles are classified as a single species, a brief internet search exposes the controversy surrounding them, with names like “Agassizi turtle,” “black sea turtle,” and “Galápagos green turtle” all appearing as proposed subspecies.
There is no doubt that turtles and dinosaurs have existed peacefully with each other. When the dinosaurs perished, the turtles did not share the same fate as theirs and thus could evolve and last until today. Turtles are known to be one of the oldest living animals on earth, and their fate of surviving when the bigger dinosaurs did not, is always going to fascinate paleontologists and people invested in dinosaurs for a long time.
● I’ve written a whole article about whether turtles are related to dinosaurs, which describes how turtles and crocodiles share an almost sibling relationship on a molecular level
● If you are interested in what features all dinosaurs have in common, I’ve written an article which explains, for instance, that all dinosaurs laid eggs and that fossil eggs have been found all over the world and on all continents