Allosaurus is a predatory dinosaur. Other ancient reptiles How much does Allosaurus weigh?

"And Thunder Rolled" 2005. Allosaurus were most vividly and plausibly presented in the BBC series Walking with Dinosaurs and the film The Ballad of Big Al.

Allosaurus was a large bipedal predator with a large skull that was equipped with dozens of large, sharp teeth. Representatives of the type species - A. fragilis(lat. A. fragilis) reached an average of 8.5 meters in length, although larger fragmentary remains suggest that large individuals could reach more than 12 meters in length. Allosaurus walked on large and powerful hind legs, while its forelimbs were relatively small and had three large, curved claws. The massive skull was balanced by a long, heavy tail. While the exact number of valid species is unknown, today the following species are distinguished:

• Allosaurus fragilis- type species, described by O. C. Marsh in 1877. Late Jurassic (Kimmeridgian - Early Tithonian) of western North America. Known from a huge number of specimens, including complete skeletons of various sizes, individuals of different ages from Colorado, Utah, Wyoming, New Mexico. Mass burials in viscous asphalt or mud “predator traps” are described at Cleveland Loyd (40 individuals). Length up to 8.5 - 12.3 meters.

• Sometimes another one is isolated from this species - Allosaurus atrox (Creosaurus)- smaller in size and with a lower skull, from Wyoming. The true status of Creosaurus is unknown, but among the Allosaurus species Allosaurus fragilis two groups of forms with preorbital horns of different configurations are observed. This may reflect sex differences.

• Recently, based on finds of almost complete skeletons in Utah and Wyoming, the species Allosaurus jimmadseni, the validity of which is not recognized by all authors.

• Allosaurus europaeus- from the late Kimmeridgian - early Tithonian of Portugal. Extremely similar to the type species, described from an incomplete skull in 2006.

• Allosaurus maximus- a giant (weighing up to 5 tons, up to 11-15 meters long) allosaurus from the Kimmeridgian of Oklahoma and Colorado. The true status is unknown. Actually Allosaurus maximus from Oklahoma is often classified as a special genus Saurophaganax. The giant Allosaurus is sometimes classified as the same species. epantherias (Epanterias amplexus) from Colorado, which is generally considered a large individual of the type species.

Allosaurus bones have been found in Late Jurassic deposits of Australia, Africa and North America (Wyoming, Utah, Colorado).

The famous “Big Al,” by the way, may belong to an as yet undescribed species. The so-called "dwarf polar allosaurus" from the Early Cretaceous (Albian) of Australia is known only from an ankle bone and cannot be assigned to the genus Allosaurus. African species Allosaurus tendagurensis cannot belong to to this genus, but undoubtedly belongs to allosaurids. It is likely that the large species of Allosaurus was a top predator at one time, and likely hunted large herbivorous dinosaurs such as Camarosaurus and Stegosaurus, and perhaps even other predators (such as Ceratosaurus). There is evidence (traces different representatives one species in one place, mass burials of the remains of one species), that Allosaurus hunted in packs, but some paleontologists believe that Allosaurus were too aggressive to live in packs.

Description

Dimensions

A.fragilis the most well studied averaged 8.5 meters in length, the largest individuals are estimated at 9.7 meters and weigh 2.3 tons. In 1976, James Madsen studied a number of skeletons different sizes, and species, as a result of which he found out that the maximum length large species reached from 12 to 13 meters. The exact weight of Allosaurus (as indeed of all Dinosaurs) is difficult to determine.

The following table shows information about the weight of Allosaurus obtained by different methods:

Skeletal structure

Allosaurus had six cervical vertebrae, fourteen dorsal and five sacral. The number of caudal vertebrae is unknown; James Madsen believes that he had at least 50, and Gregory Paul believes that in fact there were no more than 45. There were through holes in the vertebrae of Allosaurus. Birds have similar holes; they help push air out of the air sacs directly through the skin without wasting energy on exhalation from the throat; which is very convenient for large physical activity(for example, when flying). It follows from this that Allosaurus most likely intensively pursued its prey - otherwise it is difficult to explain the presence of such a method of breathing. It is possible that Allosaurus had extra ribs, like Tyrannosaurus, but perhaps these are bone fragments, and perhaps strongly fossilized thymus bone, the presence of which was proven in Allosaurus in 1996. In some Allosaurus specimens, the ends of the pubic bones are not connected; perhaps it helped them lie on the ground; James Madson believes that this helped females lay eggs and was sexual dimorphism.

Limb structure

One of the first skeletons found A.fragilis

The front legs of Allosaurus were short compared to the hind legs (in adults only about 35% of the length of the hind legs), they had three fingers that ended in large, strongly curved claws. The forearms were somewhat shorter than the shoulders (the ratio of the length of the humerus and ulna was approximately 1:1.2); the wrist was equal in length to the ulna. Of the three toes on the front paw, the middle one was the largest and differed from the others in the number of phalanges. The legs of Allosaurus were not adapted for speed of movement, but rather for stability during movement. The Allosaurus foot had three supporting toes, and one that was not used when walking. There are also signs that Allosaurus had a vestigial fifth finger on its hind leg.

Front paw A.fragilis

Structure of the skull

The skull of Allosaurus was small compared to the skulls of other Theropods, for example the skull Tarbosaurus was twice as large. Paleontologist Gregory S. Paul, having studied all the known skulls, came to the conclusion that the largest reached “only” 845 mm. Each premaxilla had five D-shaped teeth, and each maxilla had fourteen to seventeen teeth, depending on the species. Each lower jaw had from fourteen to seventeen teeth; the most common skulls were those with sixteen teeth on the lower jaw. The teeth became shorter, narrower and more curved towards the back of the skull. All teeth had sawtooth edges and were easily replaced after falling out.

The skull had paired ridges that gradually turned into horns. These horns were enlarged brow ridges, which are different for all Allosaurus. On top of the bony base of these growths there was probably a layer of keratin coating. Perhaps these ridges were intended to protect the eyes from bright sunlight, it was previously thought that Allosaurus butted them, but this idea has now been rejected as these horns are too fragile for this purpose. The salt gland could also be located inside these horns.

The air passages of Allosaurus were more developed than those of more primitive theropods such as Ceratosaurus and Marchosaurus, due to this Allosaurus had a very well-developed sense of smell, and possibly had a vomeronasal organ. The frontal bones of the skull were thin, possibly to improve thermoregulation of the brain. Between the top and lower jaw there was a well-developed hinge joint that allowed Allosaurus to open its mouth very wide.

Scull A.jimmadseni

Classification

Allosaurus belonged to the Allosauridae family from the infraorder Carnosaurs. The family Allosauridae was proposed in 1878 by Othniel Charles Marsh, but the term was not used until the 1970s, and all carnosaurids were placed in the same family Megalosauridae.

After the publication of Madsen's works on Allosaurus, the term Allosauridae began to be used by many paleontologists. As studies show, representatives of the Allosauridae family were usually larger than Megalosauridae. Very close to Allosaurids, dinosaurs such as Indosaur, Pyatnitskosaurus, Piveteausaurus, Yanghuanosaurus,Acrocanthosaurus, Hylantaisaurus, Compsosuchus, Stokeosaurus And Sechuanosaurus.

Allosauridae were one of the families, the superfamily Allosauroidae, which also included Carcharodontosavidae and Sinoraptoridae. Previously, it was Allosauroids that were considered the ancestors of Tyrannosaurids, but it has now been established that the ancestors of Tyrannosaurids are Coelurosaurs. Allosaurids include only seven genera, but sometimes more are distinguished due to the allocation Creosaurus,Epanterias And Saurophagnaxa V certain genera.

History of the study

Due to the "bone wars" between Marsh and Kuop in the 1800s, there was confusion over the names of species and genus. The first fossils were described by geologist Ferdinand Vandiver Hayden in 1869. Hayden's remains were given to him by Colorado farmers who found them in the Morrison Formation. Hayden sent the samples to Joseph Leidy, who identified the fossils as the remains of the already known European dinosaur Poequilopleron. Leidy subsequently decided that these remains deserved to be placed in a separate genus, Anthrodomeus.

The first fossils of the type species are found in the Morrison Formation. Gothniel Charles Marsh described the type species A. fragilis in 1877 on the basis of partially preserved three vertebrae, fragments of ribs, teeth, leg bones and a humerus. The name Allosaurus, which means “strange lizard,” was given due to the fact that the vertebrae of Allosaurus were very different from the vertebrae of other dinosaurs known at that time. Type name fragilis means fragile or brittle, was given due to the fragile structure of the vertebrae. Edward Cope and Charles Marsh, being in scientific competition, did not have time to compare their new finds with old ones; because of this, some fossils that now belong to species or subspecies of Allosaurus were separated into separate genera. Such pseudogenera include Creosaurus ,Labrosaurus And Epanterias.

After discovering the Allosaurus holotype description in Colorado, Marsh concentrated his work in Wyoming, then worked again in Colorado in 1883, where Deputy Flesch found an almost complete Allosaurus skeleton and several partial ones. In 1879, one of Cope's assistants found a specimen in the Como Bluff area of ​​Wyoming, but apparently Cope was unable to excavate the specimens due to their sheer quantity. When these specimens were excavated in 1903 (several years after Cope's death), they were found to be some of the most complete Therapod remains yet. It also turned out that in Como Bluff, next to the skeleton of Allosaurus, the skeleton of Apatosaurus was buried; the remains of other Theropods were also found in Como Bluff, but they are not yet opian.

Reconstruction of the holotype of Allosaurus by Charles R. Knigt

Second reconstruction of the Allosaurus holotype by Charles R. Knigt

The confusion over the names is compounded by the brevity of the descriptions created by Marsh and Cope. In 1901, Samuel Wendell Williston suggested that it was incorrect to single out Creosaurus And Epanterias into a separate genus from Allosaurus. As evidence, Williston pointed out that Marsh was never able to distinguish Allosaurus from Creosaurus. The earliest attempt to understand the situation was made by Charles W. Gilmore in 1920. He came to the conclusion that the caudal vertebrae are defined as Anthrodomeus are no different from the same vertebrae of Allosaurus. Thus, the early title should be preferred because the older titles take precedence. Since then the title Anthrodomeus was used for the name of this genus for more than fifty years, until James Madsen, examined the remains found at Cleveland Loyd and came to the conclusion that the name Allosaurus should be used because Antrodemus was described with too little material.

The dinosaur Allosaurus is bright representative predatory theropods that lived on our planet during the Jurassic period, which is 155-145 million years ago. Literally from Greek, allosaurus is translated as a strange, different lizard, and its remains were first found and studied back in 1877.

Appearance of the Allosaurus dinosaur

Allosaurus was a fairly large predator. His large and weighty skull was equipped with dozens of powerful and sharp teeth.

This dinosaur moved exclusively on two powerful hind legs; as for the front ones, they were poorly developed and the only thing remarkable about them was three curved claws.

The large tail helped the Allosaurus to balance the rather large front part and also helped with movement and maneuvers, and in its normal state, it may have helped the Allosaurus sit.

As for the sizes, they could vary within the same species. It is known that a typical representative of allosaurs was up to 9 m in length and up to 4 m in height and could weigh about a ton. But it is also known that, which could reach 11 m in length and weighed about 2 tons.

The brain of this dinosaur was very similar in structure and size to the brain of a crocodile. The skull itself was equipped with brow ridges, which, according to scientists, could serve as decoration, thereby luring the opposite sex.

Allosaurus lifestyle

Allosaurs ate exclusively food of animal origin and predatory image life. It is safe to say that in their Jurassic era they had no equal, and they were quite bright and typical representatives dinosaurs, which could not but affect the formation of the image of Allosaurus as such.

It is this species that is so colorfully described in “Park Jurassic period"S. Spielberg, and in "The Lost World" by A. C. Doyle.

Allosaurs were very voracious, which they successfully compensated for with their indiscriminateness, attacking not only any Living being, but also not disdaining carrion. According to researchers, they made short work of their prey, literally tearing it apart with their numerous and sharp teeth. At the same time, they could swallow prey in one sitting, the size corresponding to the size of a person.

Only after hatching from the egg, allosaurs, like true predators, began to conduct their first hunt. And even though at first it was insects, then birds... the prey grew as the Allosaurus itself grew larger.

Niramin - May 31st, 2016

Allosaurus is an extinct dinosaur that lived in North America. East Africa and southern Europe about 145 million years ago.

Adult males could reach a weight of 2 tons, a height of 4 meters and a length of 11 meters. They looked especially menacing. The massive head, up to 90 cm long, was located on a powerful S-shaped neck. There were growths above the eyes, brow ridges; according to some paleontologists, they served to protect the eyes from light, but there is also a version that they were decorations to attract females. The hinge joint of the jaw was positioned so that the mouth opened very wide, the mouth contained very sharp teeth 10 cm long. The sawtooth edges of the teeth curved inward, which made their bite incredibly tenacious.

Allosaurus walked on powerful hind limbs. The front legs were shorter and also very strong. The hind legs were four-toed, and the front legs were three-toed and armed with sharp claws that helped to grab the victim when attacking. With the help of a heavy, powerful tail, they maintained balance when moving.

Carnivorous allosaurs hunted alone, but could join in packs to attack giant lizards such as brachiosaurs.

A confrontation between tyrannosaurs, which lived about 65 million years ago, and allosaurs would be very interesting. Tyrannosaurs were heavier and larger, but they were also somewhat clumsy. The short, weak limbs of tyrannosaurs posed no threat when allosaurs had the power, strength and ability to hunt and pursue prey.

Below is interesting pictures, Photo and video.

Video: Allosaurus skeleton.

Video: Allosaurus Trap

Video: Allosaurus - Planet Dinosaur - Episode 4 - BBC One

Video: Tyrannosaurus Rex vs Allosaurus || Stop Motion Dinosaurs

Video: T-Rex vs. Allosaurus | Jurassic Dinosaur World Fight

Allosaurus(Latin Allosaurus; Greek αλλος - “different” or “strange”, σαυρος - “lizard”) - a genus of predatory lizard-hipped dinosaurs of the theropod suborder. They lived in the Jurassic period (Kimmeridgian - Early Tithonian) approximately 155-145 million years ago.

Allosaurus were predators that walked on powerful hind legs, while the forelimbs were relatively small. Allosaurus reached an average of 8.5 meters in length and 3.5 meters in height. Allosaurus remains are known from North America. Southern Europe and East Africa.

The first remains were studied and classified in 1877 by Othniel Charles Marsh.

Allosaurus was a large bipedal predator with a large skull equipped with dozens of large, sharp teeth. Representatives of the type species - A. fragilis (lat. A. fragilis) reached an average of 8.5 meters in length, 3.5 meters in height and weighed about a ton, although, based on fragmentary remains bigger size, it can be suggested that large individuals could reach up to 11 meters in length, about 4 meters in height and weigh about 2 tons.

Allosaurus walked on large and powerful hind legs, while its forelimbs were relatively small and had three large, curved claws. The massive skull was balanced by a long, heavy tail.

Selected types:

Allosaurus fragilis (fragilis - fragile) - type species, described by O. C. Marsh in 1877. Late Jurassic (Kimmeridgian - Early Tithonian) of western North America. Known from a huge number of specimens, including complete skeletons of various sizes, individuals of various ages from Colorado, Utah, Wyoming, New Mexico. Mass burials in viscous asphalt or mud “predator traps” are described at Cleveland Loyd (40 individuals). Length up to 8.5-12.3 meters, weight from 1 to 2 tons, height 3.5 meters.

Allosaurus atrox (Creosaurus) - smaller in size and with a lower skull, from Wyoming. The true status of Creosaurus is unknown, but among the allosaurs of the species Allosaurus fragilis, two groups of forms with preorbital horns of different configurations are observed. This may reflect sex differences.

Recently, based on finds of almost complete skeletons in Utah and Wyoming, the species Allosaurus jimmadseni , the validity of which is not recognized by all authors.

Allosaurus europaeus - from the late Kimmeridgian - early Titonian of Portugal. Extremely similar to the type species, described from an incomplete skull in 2006.

Allosaurus maximus - a giant (weighing more than 2 tons, up to 11-12 meters long) allosaurus from the Kimmeridgian of Oklahoma and Colorado. The true status is unknown. Actually, Allosaurus maximus from Oklahoma is often classified into a special genus, Saurophaganax.

The giant Allosaurus epantherias ( Epanterias amplexus ) from Colorado, which is generally considered a large individual of the type species.

Allosaurus bones have been found in Late Jurassic deposits of Australia, Africa and North America(Wyoming, Utah, Colorado).

Reconstruct appearance Allosaurus was not difficult for paleontologists, since over 60 of its skeletons of different sizes have already been found in America. In addition, scientists managed to find the remains of more than a hundred Allosaurus eggs in Portugal, and the bones of tiny babies were also preserved, which allowed scientists to fairly accurately imagine what it was like initial period the lives of these lizards.

Adults, the largest allosaurs, had a body length of up to 11-12 meters, while their weight ranged from 1 to 2 tons. Allosaurus had strong, large hind legs equipped with four toes. In this case, three fingers were facing forward, and one was facing back.

This structure of the fingers helped the Allosaurus maintain stable balance while standing on two legs, and also easily overtake any prey. His front legs were underdeveloped, although during the battle they, equipped with claws, were also used. The massive tail of the Allosaurus helped to maintain balance both in a sitting position and while running while maneuvering.

The brain of Allosaurus, according to paleontologists, was very similar in structure to the brain of a crocodile, although smaller in size. It is characteristic that alosaurs had brow ridges on their heads, which most likely helped maintain salt balance in the body. Although, according to some scientists, they were a kind of decoration, thanks to which male Allosaurus attracted females. It is these ridges that now allow scientists to easily distinguish the skull of an Allosaurus from that of a Tyrannosaurus.

Allosaurs were carnivorous dinosaurs and led a predatory lifestyle. Their prey was various herbivorous dinosaurs, which is confirmed by the found piece of the tail of the Apatosaurus, which preserved deep bite marks from the Allosaurus and its knocked out teeth.

Giant jaws and sharp teeth allowed this lizard to deal even with large animals. They also attacked predators. The voracious lizards swallowed food in huge chunks; they could swallow an animal the size of a person in one sitting.

Newborn allosaurs also had sharp teeth and were carnivores. As soon as they hatched from the egg, they began to hunt insects, and as they grew, the prey they could handle increased.

According to some scientists, allosaurs were the most common dinosaurs of the Jurassic period. In addition, Allosaurus was one of the most aggressive and voracious dinosaurs. Apart from food, allosaurs were not interested in anything, so they did not even disdain carrion...

An interesting discovery was made by paleontologists at Cleveland Lloyd in the United States, described in the famous work “The Career of Dinosaurs.” There, in one place, 44 skeletons of allosaurus were found at once. As we managed to establish, in those old times there was a swamp in this place. Due to his carelessness, a giant brachiosaurus wandered in and got stuck. A whole flock of allosaurs, which rushed for easy prey, did not take advantage of this.

However, the swamp sucked in the Allosaurus one after another. Scientists still cannot explain this behavior of the dead allosaurs, and perhaps that is why the word “allosaurus” itself means “strange lizard.”

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Allosaurus)

Allosaurus (lat. Allosaurus) - a genus of carnivorous lizard-pelvic suborder of theropods, one of the most studied carnivorous dinosaurs.
The hind limbs of allosaurs had to be very strong to support their body weight. The first toe on the foot was facing back, the other three were facing forward.
This arrangement of the fingers, according to some scientists, helped the Allosaurus, which had a very large body mass, to move with greater ease.
Being very small in comparison to the legs, the forelimbs of Allosaurus must have been strong; they ended in three terrible curved claws, which were used for tearing prey.

The massive body of the Allosaurus turned into a thick and long tail, tapering towards the end, which helped the Allosaurus maintain balance when moving or fighting with an enemy.
Probably these bloodthirsty predators hunted in packs. Together, they could defeat prey much larger than Allosaurus, such as a sauropod or stegosaurus.
The huge mouth of the Allosaurus, which was the most terrifying feature of its appearance, was bordered by sharp and inwardly curved teeth, which made them an excellent tool for tearing the flesh of an unfortunate victim. Thanks to such teeth, the Allosaurus could firmly hold prey in its mouth, which was trying to escape and escape from inevitable death.
In 1841, in Utah (USA), an entire cemetery was discovered consisting of the bones of more than 60 individuals of allosaurus.

Information sources:
1. Bailey J., Seddon T. “The Prehistoric World”
2. “The Illustrated Encyclopedia of Dinosaurs”
3. Wikipedia website
4. “From Diplodocus to Stegosaurus” (Astrel)