Huayanosaurus - Huayangosaurus - Dinosaurs. The most "bizarre" dinosaurs Dinosaur with spikes on its back title
(155-145 million years ago), lived in the western United States (approximately Wyoming and Colorado).
These dinosaurs were herbivores, moved on 4 legs, on the tail and back there are spikes and bone plates.
What did you eat and what lifestyle did you lead
Stegosaurs consumed only vegetation, as their teeth did not allow to chew something tougher. Also, the stegosaurus swallowed the whole stones, which they rubbed leaves in the stomach and helped to improve digestion.Body structure details
This dinosaur had excellent protection; solid bone growths were located all over the body, perfectly protecting its throat, legs and body.
On the back there are 2 rows of plates of various sizes, the largest plates grew to 1m. They were not particularly durable and were used more for intimidation than for protection. When the enemy appeared, the plates were painted red (color of danger), which frightened off predators, and also helped to compete for females with other males of this species. In addition, the dorsal plates were a thermostat that accumulated heat and removed its excess.
But on the tail there were very sharp spikes, making a tail strike, he could stun his attacker and even kill him. The number of such spikes could be up to 4 pieces, and their length was from 70 cm to 1 meter.
Dimensions
In length reached 9m (the largest stegosaurus was found in Arizona - 9m 79cm)
The stegosaurus was no more than 4m high
Body weight - 5-7 tons
Stegosaurus head
The head was small, especially considering the huge body of the dinosaur. The skull did not exceed 40cm in length.The brain also did not differ in great size - the size of a walnut.
Due to the underdeveloped jaws, only delicate leaves had to be eaten.
Limbs
Moved on 4 legs, the front, in comparison with the rear, were short and not so powerful. All the load came to the hind legs.Video number 2.
Video number 3.
Photos and pictures
(click to enlarge)
Stegosaurus description
It is recognized by its spiky tail and protruding bone shields running along its back.. Roof rack (Stegosaurus) - so the fossil monster called its discoverer, combining two Greek words (στέγος “roof” and σαῦρος “lizard”). Stegosaurs are assigned to the order of birds and represent the genus of herbivorous dinosaurs that lived in the Jurassic period, about 155-145 million years ago.
Appearance
The stegosaurus struck the imagination not only with a bone “mohawk” crowning the ridge, but also with a disproportionate anatomy - the head was practically lost against a massive body. A small head with a pointed muzzle sat on a long neck, and short massive jaws ended with a horny beak. In the mouth there was one row of actively working teeth, which, as they were abraded, changed to others that were deeper in the oral cavity.
The shape of the teeth testified to the nature of gastronomic preferences - diverse vegetation. Powerful and short forelimbs had 5 fingers, in contrast to the three-toed hind limbs. In addition, the hind limbs were noticeably higher and stronger, which means that the stegosaurus could rise and rest on them during feeding. The tail was decorated with four huge spikes 0.60–0.9 m high.
Plates
Pointed bone formations in the form of giant petals are considered the most striking detail of a stegosaurus. The number of plates ranged from 17 to 22, and the largest of them (60 * 60 cm) were located closer to the hips. Everyone who was involved in the classification of the stegosaurus agreed that the plates went along the back in 2 rows, but debated about their location (parallel or zigzag).
Professor Charles Marsh, who discovered the stegosaurus, was convinced for a long time that the horn shields were a kind of protective carapace, which, unlike the tortoise, did not cover the whole body, but only the back.
It is interesting! Scientists abandoned this version in the 1970s, finding that the horn jewelry was pierced by blood vessels and controlled body temperature. That is, they performed the role of temperature regulators, like elephant ears or sails of a spinosaurus and dimetrodon.
By the way, it was this hypothesis that helped to establish that the bone plates were not parallel, but dotted the stegosaurus ridge in a checkerboard pattern.
Stegosaurus sizes
The stegosaurus infraorder, along with the rooftop itself, includes the centrosaur and the hesperosaurus, similar to the first in morphology and physiology, but inferior to it in size. An adult stegosaurus grew to 7–9 m in length and up to 4 m (together with plates) in height with a mass of about 3-5 tons.
Brain
This monotonous monster had a narrow small skull, equal to the skull of a large dog, where the brain substance weighing 70 g was placed (like a large walnut).
Important! The stegosaurus brain is recognized as the smallest among all dinosaurs, if we consider the ratio of the mass of the brain and body. Professor C. Marsh, the first to discover a flagrant anatomical dissonance, decided that stegosaurs were unlikely to shine with their minds, confining themselves to simple life skills.
Yes, actually, the deep thought processes of this herbivore were completely useless: the stegosaurus did not write dissertations, but only chewed, slept, copulated, and occasionally defended itself from enemies. True, the fighting nevertheless required a little bit of ingenuity, albeit at the level of reflexes, and paleontologists decided to assign this mission to the vast sacral brain.
Sacral thickening
Marsh discovered it in the pelvic region and suggested that it was here that the main brain tissue of the stegosaurus was concentrated, which was 20 times larger than the brain. Most paleontologists supported C. Marsh, linking this part of the spinal cord (which removed the load from the head) with stegosaurus reflexes. Subsequently, it turned out that characteristic thickenings in the sacral region were observed in most sauropods, as well as in the spines of modern birds. Now it is proved that in this section of the spinal column there is a glycogen body that supplies the nervous system with glycogen, but does not stimulate mental activity.
Lifestyle, behavior
Some biologists believe that stegosaurs were social animals and lived in herds, while others (referring to the dispersal of the remains) say that the rooftop existed separately. Initially, Professor Marsh attributed the stegosaurus to the bipedal dinosaurs due to the fact that the hind legs of the dinosaur were stronger and almost twice as long as the front ones.
It is interesting! Then Marsh abandoned this version, leaning to a different conclusion - the stegosaurs, indeed, walked on their hind legs for some time, which caused a decrease in the front legs, but later again got on all fours.
Moving on four limbs, stegosaurs, if necessary, stood on their hind legs to tear leaves on high branches. Some biologists believe that stegosaurs that did not have a developed brain could throw at any living creature that came into their field of vision.
In all likelihood, ornithosaurs (dryosaurs and otheliums) roamed on their heels, which ate insects inadvertently crushed by stegosaurs. And again about the plates - they could scare away predators (visually increasing the stegosaurus), be used in mating games or simply identify individuals of their species among other herbivorous dinosaurs.
Life span
About how many stegosaurs lived, it is not known for certain.
Types of Stegosaurs
In the genus Stegosaurus, only three species have been identified (the rest cause doubts among paleontologists):
- Stegosaurus ungulatus - described in 1879 on plates, parts of the tail with 8 spikes and bones of limbs, found in Wyoming. Based on these fossils, the skeleton of S. ungulatus of 1910 was recreated, housed in the Peabody Museum;
- Stegosaurus stenops - Described in 1887 according to an almost integral skeleton with a skull, found a year earlier in Colorado. The species is classified due to fragments of 50 adults and young individuals excavated in Utah, Wyoming and Colorado. In 2013, recognized as the main holotype of the genus Stegosaurus;
- Stegosaurus sulcatus - described by an incomplete skeleton in 1887. It differed from the other two species in an unusually huge spike growing on the thigh / shoulder. Previously, it was assumed that the spike was on the tail.
The synonymous or unrecognized types of stegosaurus include:
- Stegosaurus ungulatus;
- Stegosaurus sulcatus;
- Stegosaurus seeleyanus;
- Stegosaurus laticeps;
- Stegosaurus affinis;
- Stegosaurus madagascariensis;
- Stegosaurus priscus;
- Stegosaurus marshi.
Discovery history
The world learned about the stegosaurus thanks to Yale professor Charles Marsh, who came across a skeleton of an animal unknown to science during excavations in 1877 in Colorado (north of the town of Morrison).
Stegosaurs in the scientific world
It was the skeleton of a stegosaurus, or rather, the stegosaurus reinus, which the paleontologist took for the ancient look of the turtle. The scientist was led astray by the horn-shaped back shields, which he considered parts of a split shell. Since then, the work in the district did not stop, and new remains of extinct dinosaurs of the same species as the stegosaurus reinus, but with small variations in the structure of the bones, were removed to the surface in a multitude.
C. Marsh worked day and night, and for eight years (from 1879 to 1887) described six varieties of stegosaurus, relying on scattered fragments of skeletons and bone fragments. In 1891, the public was presented with the first illustrated reconstruction of the roof-roof, which the paleontologist recreated for several years.
Important! In 1902, another American paleontologist Frederick Lucas defeated C. Marsh's theory that the back plates of a stegosaurus created a kind of gable roof and were simply an underdeveloped carapace.
He put forward his own hypothesis that petal shields (directed with sharp ends up) went along the spine in 2 rows from head to tail, where they ended with massive spikes. It was also Lucas who admitted that the wide plates protected the stegosaurus back from attacks from above, including attacks by winged dinosaurs.
True, after some time, Lucas corrected his idea of \u200b\u200bthe location of the plates, guessing that they alternated in a checkerboard pattern, and did not go in two parallel rows (as he had imagined earlier). In 1910, almost immediately after this statement, a rebuttal was made by Yale University professor Richard Lall, who stated that the staggered arrangement of the plates was not intravital, but was caused by the displacement of the remains in the ground.
It is interesting! Lull became an interested participant in the first recreation of the stegosaurus in the Peabody Museum of Natural History, thanks to which he insisted on pairwise-parallel arrangement of shields on the skeleton (based on the original theory of Lucas).
In 1914, another scholar, Charles Gilmore, entered into controversy, declaring the chessboard order of backboards completely natural. Gilmore analyzed several skeletons of the rooftop and their occurrence in the ground, finding no evidence that the plates were shifted due to some external factors.
Long scientific discussions, which took almost 50 years, ended with the unconditional victory of C. Gilmore and F. Lucas - in 1924, the reconstructed copy of the Peabody Museum was amended, and this skeleton of the stegosaurus is considered correct to this day. Currently, the stegosaurus is considered to be perhaps the most famous and recognizable dinosaur of the Jurassic period, even despite the fact that paleontologists very rarely come across well-preserved remains of this extinct giant.
Stegosaurs in Russia
In our country, the only specimen of the stegosaurus was discovered in 2005 thanks to the painstaking work of paleontologist Sergei Krasnolutsky, who excavated the Nikolsky site of Middle Jurassic vertebrates (Sharypovsky district of the Krasnoyarsk Territory).
It is interesting! The stegosaurus remains, which by approximate standards turned 170 million years old, were found in the Berezovsky open pit, the coal seams of which are located at a depth of 60–70 m. Bone fragments were 10 m higher than coal, which took 8 years to reach and to restore.
So that bones that are fragile from time to time do not crumble during transportation, each of them was cast with gypsum in the quarry, and only then carefully removed from the sand. In the laboratory, the remains were fastened with special glue, after having previously cleaned them of gypsum. It took another couple of years to completely reconstruct the skeleton of the domestic stegosaurus, whose length was four and its height was one and a half meters. This sample, exhibited at the Krasnoyarsk Museum of Local Lore (2014), is considered the most complete stegosaurus skeleton found in Russia, even despite the absence of a skull.
Stegosaurs in art
The earliest popular portrait of a stegosaurus appeared in November 1884 on the pages of the American popular science magazine Scientific American. The author of the published engraving was A. Tobin, who mistakenly presented the stegosaurus as a long-necked animal with two legs, the spine of which was dotted with tail spines and the tail with dorsal plates.
Own ideas about extinct species were captured on the original lithographs published by the German Cocoa Theodore Reichard Company (1889). These illustrations contain images from 1885–1910 by several artists, one of which was Heinrich Harder, a renowned naturalist and professor at the University of Berlin.
It is interesting! Trading cards were included in a set called Tiere der Urwelt (animals of the prehistoric world), and are still used as reference material as the oldest and most accurate conceptualizations of prehistoric animals, including dinosaurs.
The first image of a stegosaurus, made by eminent paleo-artist Charles Robert Knight (which was based on the skeletal reconstruction of Marsh), was published in one of the issues of The Century Magazine in 1897. The same drawing appeared in the book Extinct Animals, published in 1906, authored by paleontologist Ray Lancaster.
In 1912, the image of a stegosaurus from Charles Knight shamelessly borrowed Clen White, who was entrusted with the design of the science fiction novel Arthur Conan Doyle's "The Lost World". In cinema, the appearance of a stegosaurus with a double arrangement of back shields was first shown in the film "King Kong", shot in 1933.
They were herbivorous dinosaurs, and on their back was a double row of bone plates and spikes, but the stegosaurs were awkward. The plates supposedly grew from the skin, but were not connected to other bones. The exact location of these plates and studs is now very difficult to restore. Scientists are still debating about their true purpose. They could serve both for the thermoregulation of blood in the body of the animal and for its protection from predators. The tail of the stegosaurus resembled a mace with its, imposing size, spikes.
Stegosaurus:
These lizards reached a weight of three tons and were considered the largest representatives of their family. Their body had very unusual proportions: the hind legs were much larger than the front, which led to the arching of the back into a huge hump. A nut-sized brain was placed in a small head, which the reptiles constantly tilted down. Like other dinosaurs of this genus, the front of the stegosaurus muzzle looked like a beak with teeth in the back of the jaw. On the tail there were weighty spikes that could cause serious damage to the enemy. The high plates of two rows, most likely, served to scare away their rivals, and not for the sake of protection from predators. There is also an opinion that with the help of plates the dinosaur warmed up, exposing them to the sun, and turning in parallel, lowered the temperature of its body. They were supposedly on four legs during the meal, however, according to a group of scientists, they could rise on two legs to reach the tops of the trees.
Length Overall: 9 m
Time:
Fossil finds: Northwest America, Europe (England).
The five animals shown here (in the picture) show the types of “weapons” of stegosaurs. Tuoyangosaurus (2) and stegosaurus (1) had a double row of wide, spiky dorsal plates. The plates look impressive, although many paleontologists believe that they were too thin and could not serve as protection. In lexovisaurus (4), ketrosaurus (5) and dacentrum (3), the plates were somewhat narrower and closer to the tail they took the form of spikes. Each of the five animals was characterized by features characteristic of all members of this family - elephant-like legs, a curved back and a small narrow head.
The stegosaurus belonged to the dinosaur family, which had a double row of bony plates along the spine from neck to tail. For defense purposes, it used a tail with sharp spikes at the end.
Stegosaurus lived about 170 million years ago. Despite its terrifying appearance, it was a peace-loving herbivore. It is likely that he lived in herds. They provided him with security rather by their numbers than by the militancy of the members of the herd.
Special signs
Stegosaurus are dinosaurs that have a double row of bone plates on their backs along the ridge.
There are many theories trying to explain the purpose of the plates, the highest of which was 60 cm high. Some argue that the plates were needed for self-defense. Other theories state that they served the purpose of temperature regulation.
If the plates were covered with skin with many blood vessels, then facing the sun, they could serve the animal to heat the body; placed in the shade, cool the body.
At the end of the tail, the stegosaurus had 4 spikes, which he apparently used for defense.
The stegosaurus did not belong to the largest dinosaurs, however, its length reached 9 meters. The forelimbs were half shorter than the hind limbs, so the stegosaurus moved, leaning forward strongly.
The head of the stegosaurus was very small, about 45 cm in length, and almost touched the ground.
His brain was also small - about 3cm
Habitat
The stegosaurus lived a little more than 170 years millions of years ago on the ancient continent from which North America was later formed. At that time a warm, almost tropical climate prevailed there, ideal for such a herbivore as a stegosaurus.
The vegetation that grew on the continent, at first glance, resembled a modern tropical forest, but today's plant species did not exist at that time.
There were no flowering plants.
Everywhere, along with ferns and coniferous trees, ancient palm trees grew that looked reminiscent of modern ones.
Food
The stegosaurus was a herbivore and fed on many species of plants. At that time in the history of the Earth, tropical climate prevailed in America, the land was covered with lush vegetation.
Studies of fossilized skeletons showed that the stegosaurus had strong spinal muscles associated with outgrowths at the hips at the base of the tail.
obviously, they allowed the stegosaurus to rise on its hind legs, thanks to which it took out high-growing plants. However, it was not specially adapted to plant foods, its teeth were small and weak. It is believed that he, like other dinosaurs and modern crocodiles, swallowed stones to grind plant fibers.
Breeding
One of the reasons explaining why dinosaur study is such an exciting activity is that very little is known about them. Therefore, there is a chance to make a discovery, and finds can lurk in the ground right under our feet.
It is known that dinosaurs, including the stegosaurus, laid several relatively small eggs in shallow holes dug in the ground. The eggs were covered with sand so that the sun would warm them. Newborn cubs grew very quickly so as not to become easy prey for predators. To protect the predators, the cubs were placed in the center of the herd. Since the stegosaurus was a herd animal, the males fought for the right to control the female and lead the herd. In such situations, herbivores only make threatening sounds and demonstrate their strength without entering into an open duel.
Enemies
The peace-loving stegosaurus often fell prey to predatory dinosaurs such as the dangerous tyrannosaurus.
Stegosaurus, most likely, was rather slow and defenseless, especially when attacking from the side and in the area of \u200b\u200blegs. He was slow and therefore could not escape from predators. He defended himself, unexpectedly striking with a tail studded with thorns. Each of the spikes on the tail was about 1 meter long. The stegosaurus had 2 pairs.
Some species related to the stegosaurus had 4 pairs of spikes. The spikes were keratinized enough and could seriously injure the enemy if he fell into the field of their reach.
Stegosaurus (Stegosaurus)
Stegosaurs(lat. Stegosaurus - “rooftop”) is a genus of Late Jurassic herbivorous dinosaurs that existed 155-145 million years ago (Kimmeridge tier). It consists of three species. Thanks to the spikes on the tail and bone plates on the back, they are some of the most recognizable dinosaurs.
The fossil remains of a stegosaurus (Stegosaurus armatus) were first discovered by G. Marsh in 1877 north of the town of Morrison, in the state of Colorado. The name was compiled by the March from the Greek. στ] γος (roof) and σαρος (lizard), since the paleontologist considered that the plates lay on the back of the dinosaur and formed a kind of gable roof. At first, many species of stegosaurs were described, which were subsequently combined into three.
Marsh believed that the stegosaurus moved only on two legs, since the forelimbs were significantly shorter than the hind legs. However, already in 1891, having appreciated the physique of a dinosaur, he changed his mind.
| Title | Class | Squad | Detachment | Suborder |
| Stegosaurus | Reptiles | Dinosaurs | Poultry | Thyreophores |
| Infra squad | Height / length | Weight | Where he lived | When he lived |
| Stegosaurs | 4 m / 9 m | 2-4 t | North America, Portugal, Russia | Jurassic period (155-145 million years ago) |
The stegosaurus had a brain the size of a walnut; however, thanks to bone plates, he could perfectly control body temperature and defend himself. The stegosaurus was forced to spend most of its time looking for whether any of the many ferocious predators were on the horizon. But at the slightest opportunity, this dinosaur protected by plates started up his toothless beak and ate the nearby vegetation.
The remains of the stegosaurus skeleton are easily distinguishable due to the impressive row of plates running along the entire back of this animal. These plates served as good armor that protected, at least to a certain extent, from predators such as the terrible allosaurus. The tail was equipped with spikes and thus could be used to deliver effective side impacts.
But these plates were beneficial even when there were no predators nearby. If in the early Jurassic morning, when the temperature was probably quite low, the stegosaurus turned sideways to the sun, so that the sun's rays fell on the wide sides of the plates, his whole body gradually warmed up.
At noon, however, it could get too hot. Then this animal could turn so that the plates did not absorb so much heat.
In many ways, such a heating system is similar to the special panels that absorb solar heat that some modern homes are equipped with. Scientists also found signs on the plates that blood vessels might have passed through them. At first, some scientists even claimed that these plates could change their position, so that the stegosaurus could lower them horizontally. But today this theory does not find much support.
Recognized Species:
Stegosaurus armatus - the first open species, known for two incomplete skeletons, two skulls and individual bones of at least 30 individuals. It had 4 spikes on the tail and relatively small plates, reaching a length of 9 meters.
Stegosaurus stenops - described by the March in 1887 on fossils from the state of Colorado. A complete skeleton of a representative of the species and about 50 fragmentary was found. There was less S. armatus, reaching only 7 meters, but had larger plates.
Stegosaurus longispinus - Described by Charles Gilmore on one incomplete skeleton from Wyoming. Also reached 7 meters, but had the longest spikes. Some researchers belong to the genus Kentrosaurus.
The only skeleton of the stegosaurus in the Russian Federation, found in Jurassic deposits (170-165 million years ago) from a coal mine in the Sharypovsky district of the Krasnoyarsk Territory, is exhibited in the Krasnoyarsk Museum of Local Lore.
