What else do you know about dinosaurs? Write it. Name, form, living habits.

Dinosaur is a reptile that appeared in Mesozoic (Triassic, Jurassic and Cretaceous). The vigorous limbs, long tail and huge body are the portrayal of most dinosaurs. They mainly inhabit woodland or open areas in lakeshore plains (or coastal plains).

The sudden disappearance of dinosaurs at the end of Cretaceous 65 million years ago became a mystery in the evolutionary history of life on earth. This mystery has not been solved so far. In the past, all living things on the earth were recorded in fossils. Many dinosaur fossils have been found in Mesozoic strata. A large number of bones or various shapes can be seen in it.

2. Form

The dinosaur bones have some evolutionary adaptations, which can be distinguished from the original ancestors of the main dragon. In the late dinosaur period, these characteristics experienced more evolutionary changes.

The * * * features of dinosaurs include:

(1) posterior frontal bone loss.

(2) The humerus has a low triangular ridge attached to the sternocleidomastoid muscle, which is about 1/3 ~ 1/2 of the humerus.

(3) There is a protruding block at the back of the intestinal bone, and the acetabulum is perforated.

(3) The distal tibia has a wide edge and a backward flange.

(4) The talus has obvious protrusion, which is consistent with the tibia.

Dinosaurs as a whole are very big. According to dinosaur standards, lizard's foot is one of the behemoths. In the long dinosaur era, even the smallest sauropods were larger than other animals in their habitats, while the largest sauropods were several grades larger than any animals that appeared on the surface.

Most dinosaurs were much smaller than large sauropods. The existing evidence shows that the average size of dinosaurs changed constantly in Triassic, Early Jurassic, Late Jurassic and Cretaceous.

Most theropod dinosaurs weighed between 100 and 1000 kg, while most Holocene carnivores weighed between 10 and 100 kg. The estimated weight of dinosaurs is mostly between 1 and 10 metric tons. A study by the National Museum of Natural History in London pointed out that the average weight of dinosaurs was about 100 kg, while the average weight of new generation mammals was between 2 and 5 kg.

Judging from the existing intact bones, the tallest and heaviest dinosaur is the long-necked dragon. The fossil of long-necked dragon was found in Tanzania from 1907 to 19 12. A skeleton model composed of several individuals of similar size is now on display at the Humboldt Museum in Berlin. The model is 12 m high and 22.5 m long, and the estimated live weight is between 30 and 60 metric tons.

3. Living habits

There are many kinds of dinosaurs, and their shapes and habits are very different. The largest fragile double-chambered dragon may be more than 50 meters, while the smallest hummingbird may be less than 10 cm. As far as eating habits are concerned, there are docile herbivores and fierce carnivores, as well as omnivorous dinosaurs who are both vegetarian and vegetarian.

4, the famous top ten carnivorous dinosaurs

Most carnivorous dinosaurs belong to theropod, and they are usually called carnivorous dinosaurs or theropod carnivorous dinosaurs.

The top ten carnivorous dinosaurs are Spinosaurus, Tyrannosaurus Rex, Tyrannosaurus Rex, Mapulong, Squatting Tooth Dragon, Oshara Dragon, Southern Dragon, Zhucheng Tyrannosaurus Rex, Queirolast and so on. Sietzosaurus (calculated by size), Spinosaurus is the largest of all carnivorous dinosaurs at present. In addition, Afraid of Dragons, Ji Runhall Dragons, Spinosaurus, Sauron Dragons, etc. It was also a very big carnivorous dinosaur.

Step 5 classify

Traditionally, dinosaurs were divided into three categories: sauropods (hip bones like lizards), birds' hips (hip bones like birds) and slow dragons.

Among sauropods, its belt is very similar to that of existing reptiles. In its hip system, the pubic bone extends forward and the ischium extends backward.

In the bird's hip, it has a more complex band structure. In the hip system, the pubic bone has turned to the back of the body and arranged parallel to the ischium, which is somewhat similar to modern birds. At the same time, birds and buttock mandibles also developed anterior teeth bones.

Slow dragon (meaning dinosaur with slow movement and lizard belt structure) has a very strange belt structure, called back waist type; Its ilium is quite wide and separated from each other, in which the front section is very deep and long, and the tip extends outward to a vertical position of nearly 90 degrees.

Extended data

German scientists suggested that the extinction of dinosaurs was caused by the bad "space weather" at that time, that is to say, the strong particle flow from the universe broke into the earth's atmosphere, causing drastic changes in the earth's climate and leading to the extinction of dinosaurs.

The hypothesis that asteroids hit the earth put forward by American physicist Luis Alvarez has attracted much attention. Alvarez believes that an asteroid with a diameter of about 10 km hit the earth at the end of Cretaceous, and the dust produced covered the sky. It caused great changes in the surface climate environment and led to the extinction of dinosaurs.

Scientists believe that the explosion of cosmic particle flow led to the drastic change of the earth's climate conditions, and dinosaurs that could not adapt to this climate change became extinct in a short time.

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