The Allosaurus was one of the first dinosaurs to be discovered, since its fossils are very abundant. This large carnivorous dinosaur lived on Earth more than 150 million years ago, during the late Jurassic period. There are fossils of this theropod in many countries, although the Cleveland Lloyd Quarry in Utah (United States) stands out, the place with the highest concentration of dinosaur bones in the world.
The name Allosaurus is derived from the Greek allos (different) and sauros (lizard). It was so named because its vertebrae were totally different from those of any other known dinosaur. In fact, some vertebrae in this dinosaur were shaped like an hourglass.
How did the allosaurus live?
According to a study published in the Journal of Morphology, Allosaurus reached their adult size at 15 years old and lived for approximately 28 years. In addition, they had a short neck and an elongated skull that was excessively large, similar to those of other carnivorous theropods. However, unlike other theropods, these dinosaurs had a pair of small horns above their eyes.
The mouth of this dinosaur contained dozens of sharp teeth that were serrated on the front and rear edges. Likewise, the bones that made up the tip of the snout had approximately five teeth, while the bones of the upper and lower jaw each had between 14 and 17 teeth. In addition, it is likely that this species replaced the teeth that it lost due to food, as suggested by various studies.
The body of the Allosaurus was supported by its two hind limbs and its large tail. Each foot had three toes that supported its weight, as well as an inner spur. For this reason, a study published in the journal Proceedings of the Royal Society B affirms that this dinosaur could run up to 33 kilometers per hour.
Its fossil remains
The first fossil of Allosaurus was discovered in Colorado (United States) in the year 1877. This specimen was named Marsh, although only a few fragments remained of it. A more complete Allosaurus was found in 1879, although it was not examined until 1903 after the death of Hubbell (the researcher who found the remains).
In 1991 a team of researchers from the University of Wyoming (United States) found a fossil of this dinosaur, which was practically intact. In 1996, this same team discovered ‘Big Al Two’, the best preserved Allosaurus skeleton to date.
