In ancient Greek, Tyrannosaurus means "tyrant lizard". Tyrannosaurus, also known as Tyrannosaurus rex, is about 13 meters long and weighs about 7 tons. It is a large carnivorous dinosaur. Living in the last 3 million years of the Maastrichtian stage at the end of the Cretaceous period, about 68.5 million to 65.5 million years ago, they were one of the last dinosaur populations before the Cretaceous-Tertiary extinction event. Tyrannosaurus fossils are mainly distributed in the western regions of the United States and Canada in North America, and are also distributed in small quantities in Xinjiang and Henan of China in Asia.
Basic characteristics of Tyrannosaurus
Tyrannosaurus
Tyrannosaurus, like other tyrannosaurids, is a bipedal dinosaur with a large head. The skull, long and heavy tail is mainly used to maintain the balance of the body. The forelimbs of Tyrannosaurus were relatively small, while the hind limbs were very strong. For a long time, scientists believed that Tyrannosaurus had only two fingers. However, in 2007, a complete Tyrannosaurus fossil was discovered. The information presented by this fossil is that Tyrannosaurus may have three fingers.
Scientists analyzed the arrangement and shape of Tyrannosaurus' teeth to understand its eating habits. At that time, they concluded that Tyrannosaurus might be a carnivorous apex predator. The main prey targets are hadrosaurs and ceratopsian dinosaurs. However, as scientists use the bones of Tyrannosaurus to make models to simulate their behavior, the results are that Tyrannosaurus may be a scavenger. Also, some scientists pointed out that at that time, there was simply not enough meat for Tyrannosaurus to eat, so most of the time they were vegetarian. These views are all contradictory, and there is no unified conclusion yet. There are some theropod dinosaurs that are about the same size as Tyrannosaurus, and perhaps larger than Tyrannosaurus, but even among them, Tyrannosaurus is still the largest tyrannosaurid and the most famous land predator. one of those. Judging from the most complete preserved Tyrannosaurus fossil, the body length of Tyrannosaurus is 12.8 meters and the hip height is 4 meters. This size is second only to the largest Spinosaurus. So far, the largest known Tyrannosaurus skull is , length is 1.5 meters. Compared to other theropod dinosaurs, the skull of Tyrannosaurus was very large. The skull shape of Tyrannosaurus is wide at the rear, narrow in the snout, and the eyes are facing forward. This also makes the visual overlap area of ??their eyes relatively large, so they can see a wider three-dimensional image, so the exposure Dragons have excellent stereoscopic vision. This is something other types of dinosaurs don't have.
Tyrannosaurus has a fixed nasal bone, mainly to prevent the bones from sliding. There are large holes in its skull, whose main function is to reduce the weight of the head and also provide attachment points for muscles. There are many bones in the skull, and there are tiny spaces within the bones. The main function is to make the head lighter and more flexible. The characteristics of Tyrannosaurus gave it an increasingly powerful bite force, giving it an advantage over other non-tyrannosaurid theropod dinosaurs.
Most tyrannosaurs have a V-shaped front end of their mandibles. However, the front end of the tyrannosaurus's mandible is U-shaped. The front end of this U-shaped mandible increases The volume of flesh that the Tyrannosaurus could tear through in a single bite also increased the pressure on its front teeth. There are multiple bones in the Tyrannosaurus' jaw, which can be said to be its main component. Its main function is to absorb the shock force when prey struggles to prevent damage to the jaw.
The predecessor of Tyrannosaurus
In the world, 90% of leaf fossils were found in North Dakota. Flowering plants appeared in the early Cretaceous. Dominate the world's ecosystem, and among the more than 30,000 leaf fossils collected, 90% of the fossils belong to broad-leaf plants. Today, in the places where Tyrannosaurus once lived, you can still see coniferous plants such as larch and its relatives from the Tyrannosaurus era. At that time, the scenery was very similar to Florida or southern Georgia. In this area, there were A small tree with a height of 30 to 15 meters and a trunk diameter of less than 0.3 meters. In the era when Tyrannosaurus lived, all modern plant families had already appeared. Tyrannosaurus appeared in the late period of the dinosaur age. Their earliest ancestor was Eoraptor, which came from the late Triassic period. At that time, it was only 0.9 meters long and weighed only 5 to 7 kilograms. Vegetarian dinosaurs all had attachments in the middle of their lower jaws, but Eoraptor did not. In the middle of Eoraptor's jaw, there is a movable joint that allows the jaw to bend. When the jaws bite something, they will tightly clamp the prey. Tyrannosaurus also has this kind of jaw.
Scientists have conducted in-depth research on how Tyrannosaurus grew to such a large size. Finally, they believe that the predecessor of Tyrannosaurus may have been a celibate dragon, which had a slender body and a Longer forelimbs, by the time it evolved into Albertosaurus, its head had become larger and its forelimbs had become shorter. Albertosaurus is very similar to Tyrannosaurus, but if you look closely at their respective characteristics, you will find that Albertosaurus is more primitive than Tyrannosaurus.