When it comes to “Jurassic Park”, people think of dinosaurs. “Jurassic Park” has long been synonymous with dinosaur habitat in the prehistoric world. In people’s imagination, “Jurassic Park” can be a tropical grassland with abundant water and grass, a temperate forest with bushes, or even a warm and humid swamp. Few people will “arrange” it in the cold, desolate and extreme polar regions
Although the above ideas are very common sense, people will be surprised by the fact that a large number of dinosaur fossils unearthed on earth have been excavated in the cold polar regions for decades. Perhaps there was a “Jurassic Park” – in the polar region?
Polar home
As early as the 1960s, scientists first discovered dinosaur fossils in Alaska near the Arctic. Shortly after that, scientists found the world’s largest polar dinosaur gathering place in the Colville River Basin 400 kilometers north of the Arctic Circle, which provided irrefutable evidence that “there were a large number of dinosaurs living in the Arctic”.
This dinosaur colony is a group of rocks deposited on the coastal plain of the Arctic Ocean, which was formed about 69 million years ago. Decades of scientific investigation shows that this stratum is rich in fossil resources, including the remains of birds, fish, small mammals and a large number of dinosaur fossils. So far, tens of thousands of dinosaur fossils have been unearthed here, and their types are also very comprehensive.
There are not only grass eating dinosaurs such as platypus, Horned Dragon and dome dragon, but also carnivorous dinosaurs such as Tyrannosaurus Rex, dinosaur and Velociraptor, and even some brand-new dinosaur species that have never been seen elsewhere. This shows that in the Jurassic and Cretaceous, the heyday of the dinosaur family, there were enough trees, ferns and mosses in the Arctic.
Herbivorous dinosaurs, small mammals and carnivorous dinosaurs hunting them once lived together in this frozen soil.
On the other side of the earth, at the south pole, scientists also found the remains of dinosaurs. In 1991, scientists found fossils of iceridge dragons in the early Jurassic strata of Antarctica. Iceridge dinosaur is a fierce carnivorous dinosaur, which lived in the early Jurassic 190 million years ago.
During that period, Australia was connected with the Antarctic continent and stopped at the southernmost end of the earth. It also belonged to the cold and frozen polar region. In the early Cretaceous 100 million years ago, Australia just began to show weak signs of breaking away from the Antarctic continent and drifting northward at the speed of a snail.
Today, the Victoria coast in southeast Australia is where Australia and the Antarctic continent were once connected. The early Cretaceous strata here have become the “exhibition hall” of polar dinosaur fossils. In addition to a wide variety of dinosaur fossils, many cliffs and rocks on the Victoria coast also record the soil layer accumulated by geological sedimentation for hundreds of millions of years, including dinosaur footprints.
Some footprints come from the small and lovely ralinolone, which is shaped like a chicken’s claws; Others had larger footprints, tens of centimeters long, and came from a variety of large theropod carnivorous dinosaurs – all of them were active members of the Antarctic “dinosaur circle” at that time.
“Birth and settlement”
It is certain that dinosaurs once lived in the polar regions. What scientists want to know is whether dinosaurs migrated to the polar regions seasonally or lived there all year round.
Geological research shows that during the Jurassic and Cretaceous, the temperature of the earth’s polar regions may not be as low as today. Although the Antarctic and Arctic are still very cold in winter, the temperature here may be just cool and comfortable in summer.
Therefore, dinosaurs may go to cold places in summer and return to warm places in winter, just like today’s migratory birds. Scientists initially thought that some giant dinosaurs, such as Edmonton dragon and dome dragon, were bigger than elephants and could run long distances at the speed of several kilometers per hour.
If these large herbivorous dinosaurs were migrating, then there might have been a scene similar to the migration of herbivores on the tropical grassland at that time – groups of herbivorous fat dragons were hurrying along, and a group of drooling Tyrannosaurus Rex followed behind the herbivorous Fat Dragon, waiting for the opportunity to hunt some lonely people ……
However, with the further investigation of polar dinosaurs, scientists believe that dinosaurs there are more likely to live in cold areas all year and can’t leave.
In 2021, scientists found thousands of fossils of tiny dinosaurs in the Prince Edward River Formation in Alaska. They all came from hatching or newborn dinosaur cubs, which not only proved that adult dinosaurs lived together with cubs in the polar region, but also proved that dinosaurs directly multiplied in the polar region.
Considering that migration was a very hard job, dinosaurs needed to store enough physical strength and endure a long period of fasting. Smaller dinosaurs, such as the pentiosaurus and the leinonosaurus, were only a little bigger than puppies and did not have this ability;
Those larger herbivorous dinosaurs may be able to travel long distances, but the body length and weight of their cubs are often only 10% of those of their parents. The gap is too obvious. The cubs can’t keep up with the speed of their parents’ long journey.
In addition, scientists have also studied the incubation cycle of dinosaurs. It is estimated that the incubation period of small dinosaurs is about 3 months and that of large dinosaurs is about 6 months. Excluding the time required for the growth of cubs, dinosaurs have no time to migrate long distances between winter and summer. It is the most reasonable choice for them to settle in the polar region for the winter.
Unsolved mystery
Dinosaurs lived in the polar regions all their lives. How did they adapt to the dark and cold climate? Scientists have made some conjectures based on the study of dinosaur fossils.
First, polar dinosaurs may have night vision. For example, ralinolone in Australia weighs only 10kg and is only a little larger than Turkey.
However, fossil studies show that ralinolone has very large eyes and relatively developed brain, which help it to move frequently in the long winter polar night in Antarctica.
Similarly, the physiological characteristics of big eyes and big heads also appeared in Arctic dinosaurs, which was very helpful for them to cope with the darkness of the Arctic.
Second, polar dinosaurs may have feathers. Dinosaur fossils unearthed in the polar regions show that many dinosaurs have fluffy fluff on their necks, backs and tails. This fluff may have patterns, which can not only keep warm, but also help to absorb heat in the sun.
Third, polar dinosaurs may hibernate. Dinosaurs have always been regarded as cold-blooded reptiles. Reptiles basically hibernate in cold winter. Although various functions of the body will stagnate, they can avoid the cold.
Mammals and birds, which are warm blooded animals, do not do so. Scientists studied the polar dinosaur fossils excavated in Australia and found that some dinosaurs had growth stagnation, while others did not.
This shows that polar dinosaurs can adopt different strategies in dealing with severe cold. Like cold-blooded animals, they can choose to hibernate in caves deep in the woods or below the surface. However, it seems that they can also move freely in ice and snow like warm blooded animals, looking for food to keep out the cold.
Dinosaurs can spend their lives in the polar regions, which has led scientists to re-examine the cognition of dinosaurs – are they warm blooded animals, and what contributed to their extinction?
After all, if dinosaurs had been able to adapt to the long-term cold and darkness, why couldn’t they survive on the earth obscured by dust and sunlight after the asteroid hit the earth? These are the puzzles that scientists need to solve in the future.
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