Hadrosaur

Hadrosaurs were a group of dinosaurs that lived in the Late Cretaceous Period, about 86 to 66 million years ago.
They are also known as duck-billed dinosaurs, because of the flat shape of their snouts.

Hadrosaurs were widespread and diverse, and inhabited different continents and environments.
They are mostly found in North America and Asia, but some fossils have also been discovered in Europe, Africa, and South America.

Some of the most famous hadrosaur species include Hadrosaurus, the first dinosaur skeleton to be mounted; Edmontosaurus, one of the largest hadrosaurs; Parasaurolophus, which had a long, curved crest on its head; and Maiasaura, which means "good mother lizard" and is known for its parental care.

Hadrosaurs were herbivorous, and had complex teeth that allowed them to grind tough plant material.
They also had a predentary bone, a unique feature of ornithischian dinosaurs, that helped them crop vegetation with their beaks.

Hadrosaurs were able to walk on both two and four legs, depending on the situation.
They had long, powerful hind limbs and shorter, but robust, forelimbs.
They also had hoof-like claws on their toes, and some had skin impressions that suggested they had webbed feet.

Hadrosaurs are divided into two main groups: the lambeosaurines, which had hollow crests or tubes on their heads; and the saurolophines, which lacked hollow crests, but some had solid ones.
The crests may have been used for display, communication, or thermoregulation.

A hadrosaur is a type of dinosaur that belongs to the family Hadrosauridae, also known as the duck-billed dinosaurs.

Hadrosaurs had a flat, broad snout that resembled a duck's bill, which they used to crop foliage from plants.

They also had a complex and specialized dentition, with hundreds of teeth arranged in rows that formed a dental battery.

Hadrosaurs were large animals, ranging from 7 to 8 meters (23 to 26 feet) in length and 2 to 4 tons (2.2 to 4.4 short tons) in weight.

They had robust bones and stiff tails, supported by ossified tendons, that helped them balance on their hind legs.

They could walk on either two or four legs, depending on their speed and terrain.

There are two subfamilies of hadrosaurs: the Lambeosaurinae and the Hadrosaurinae.

The lambeosaurs had a crest on their skull, which contained the nasal passages that looped through the crest and formed chambers before entering the airway.

The crest may have served as a resonating chamber, allowing lambeosaurs to make loud sounds for communication or display.

Some examples of hadrosaurs are Hadrosaurus, the first dinosaur skeleton to be mounted; Maiasaura, the "good mother lizard" that cared for its young in nests; and Parasaurolophus, a lambeosaur with a long, curved crest.