Of course, the leatherback turtle, the largest existing sea turtle, is actually a small pudding compared to its ancestors.

Although Li Xuan was not lucky enough to see the remains of ancient sea turtles, he still knew a little about ancient sea turtles.

Speaking of ancient sea turtles, we cannot do without the remains of five ancient sea turtles discovered by humans.

In 1**5, paleontologist George Reb Wieland discovered huge paleontological fossils along the Cheyenne River in Custer County, South Dakota, North America.

Wieland transported the excavated fossils to Yale University's Peabody Museum of Natural History.

When the fossil was cleaned and mounted, what appeared in front of people was a super huge sea turtle fossil.

The completeness of the fossil is quite high, with only the skull and right hind limb missing. Paleontologists speculate that the missing right hind limb was attacked by other predators and torn off by a huge external force.

The local scientific research team immediately started excavation work there, and three years later, a second ancient sea turtle fossil was discovered in the same area, including a skull.

After studying the fossil of the giant prehistoric sea turtle, Wieland named the big thing Archaeus, whose genus name comes from the ancient Greek "pxη" meaning first, and "xeλνη" meaning turtle.

Meaning this is an early sea turtle.

The type species of the ancient turtle is called the mighty ancient turtle.

Although the Chinese names of ancient turtles also include ancient giant turtles, emperor turtles, etc., according to the meaning of the scientific name, ancient turtles are more accurate.

In 1900, Wieland named the second species of the genus Palaeochelonus, Turtle's horse, based on new fossils. The species name was dedicated to the famous paleontologist O'Neill Charles Marsh.

In 1909, Wieland realized that Protechelona martensi was actually a member of Protechelon martensi, so he changed its name to Protechelon martensi.

In 1902, paleontologists discovered a third ancient sea turtle fossil on the Cheyenne River. This fossil was more complete.

Ninety years later, in 1992, the fourth ancient sea turtle fossil was discovered in Oglalacta County, South Dakota. This was also the largest ancient sea turtle fossil ever discovered, and was nicknamed Brigitte.

Ten years later, in Cooperstown, North Dakota, a fisherman accidentally discovered the fifth ancient sea turtle fossil. This fossil was not very complete.

To date, humans have discovered a total of five fossils of ancient sea turtles.

The ancient sea turtle is the ancestor of the sea turtle and the largest sea turtle known to mankind.

Even though the length of the specimen has reached four meters, it still cannot represent the true maximum size of ancient sea turtles.

The famous Brigitte is the largest known ancient sea turtle, with a body length of 4.6 meters, a width of four meters between flippers, and a weight of more than two tons.

Compared with the leatherback turtle, the largest sea turtle today, the ancient sea turtle is really a big brother. The large leatherback turtle only weighs 700 kilograms. Even the extreme individual leatherback turtle, which is estimated to weigh one ton, cannot compete with the ancient sea turtle.

compared to.

The reason why ancient sea turtles are said to be the ancestors of leatherback turtles is that the appearance of ancient sea turtles is very similar to today's leatherback turtles.

Second, there is indeed a certain affinity between the two.

The ancient sea turtle had a large and long head, even longer than the upper body of an adult.

The front part of the ancient sea turtle's mouth is similar to that of a parrot, with a hard horny beak that has a large bite force.

There are nostrils in the front of the ancient giant tortoise's head, and a pair of big eyes on both sides of the back of the head.

This appearance is really very similar to that of the sea turtle, so some people once thought that the sea turtle was actually an ancient sea turtle, but it was a biological degradation, and its body size became longer and smaller. But this view is obviously not true.

widely recognized.

Although judging from the appearance of the two, apart from their size, including the structure of their bodies, they are very similar.

The body of ancient sea turtles was oval, and the ribs had become part of the support for the large body.

Like the leatherback turtle, the giant tortoise's body was covered with hard leathery skin rather than the hard shell of a turtle.

The ancient giant tortoise has a thin and short tail on its back, and its limbs have long evolved into flippers for swimming. The pair of flippers in front are huge and the ones in the back are relatively small.

Judging from the fossils, the humerus of the ancient turtle's forelimbs was huge in proportion, while the radius and ulna were much more compact, indicating that it mainly relied on the front pair of flippers to swim.

But the habits of ancient sea turtles and sea turtles are completely different.

The sea turtle can travel around the world, and it is possible to find the sea turtle in all sea areas around the world.

Unfortunately, ancient turtles have basically only been found in North America.

Moreover, paleontologists have discovered after very rigorous investigations that ancient sea turtles lived in the Late Cretaceous period 80 to 70 million years ago, and their fossils show that they lived in the Western Inland Seaway.

It is a warm, shallow sea that bisects North America.

Judging from the body structure of ancient sea turtles, they were not suitable for ocean cruising, so they lived in shallow seas most of the time.

In terms of feeding habits, compared with leatherback turtles, ancient sea turtles are more carnivorous. They will dive into the seabed to find bivalves with hard shells, and then use their powerful mouths to crush the outer hard shells and eat the insides.

of meat.

In addition to bivalves, the ancient turtles' food may also include ammonites, nautiluses, squid, fish, etc.

In short, the ancient sea turtle may be the ancestor of the sea turtle, but the two are by no means the same creature.

Why ancient sea turtles became extinct is an unsolved mystery just like the dinosaurs.

However, compared with the extinction of the larger dinosaurs, it does not seem surprising that ancient sea turtles became extinct in the late Cretaceous.

Although the ancient sea turtle was huge in size, it was actually a tiny creature at that time, and its life was not easy.

Ancient sea turtles, like the leatherback turtles, also had to climb onto the beach to lay their eggs and then return to the sea.

Therefore, newborn ancient sea turtles do not have any protection. The first thing in their lives is to crawl to the sea.

It is not safe for young ancient sea turtles to enter the ocean. Large carnivorous fish, mosasaurs, etc. will hunt them.

Danger is not only hidden in the ocean, but there are also terrible killers hidden in the waters that border the sea and land.

During that period, Deinosuchus, known as the largest crocodile, often entered the ocean to hunt.

The huge, relatively slow-moving ancient sea turtles were Deinosuchus's favorite prey.

The huge bite force of Deinosuchus's mouth and the teeth suitable for crushing hard shells can completely deal with the hard shells of ancient sea turtles.

In addition to Deinosuchus, large predators such as the chalk-shelled shark and Tylosaurus in the Western Inland Seaway at that time would also attack adult ancient sea turtles.
Chapter completed!