The Claosaurus dinosaur (Claosaurus agilis) was a herbivorous dinosaur that lived during the Late Cretaceous period. It was quite small in size, as seen in its specimens. Its remains were discovered in Kansas in 1871 in marine sediments and were originally considered as a Hadrosaurus until it was discovered to have significant differences and was given its own genus - Claosaurus. Originally named the Hadrosaurus agilis, its name was changed to Claosaurus agilis in 1890 owing to this genus change.
Claosaurus is pronounced as 'kla-o-sao-u-rus'.
The Claosaurus was a type of primitive hadrosaur or duck-billed dinosaur, belonging to the order Ornithischia and suborder Ornithopoda.
The Claosaurus is known to have walked the Earth during the Late Cretaceous period, an age which lasted from about 66-100 million years ago.
The Claosaurus dinosaurs all died out around 66 million years ago. They are believed to have lived during the Late Cretaceous period, which ended around 66 million years ago, after which these dinosaurs most likely ceased to exist.
Around three specimens of this hadrosaurus dinosaur have been found, each in Kansas (Smoky hill river), Montana (Pierre Shale), and North Dakota (Pierre Shale), which hints at this dinosaur being found around central North America.
The fossils of the Claosaurus specimens have mostly been discovered in shale formations or coastal environments, which shines a light on the theory that they most probably preferred to live near water bodies such as rivers or lakes. This however could just be the result of their bones being swept out to these locations due to flooding.
This hadrosaurus dinosaur mostly lived in packs. There are high chances of herbivorous dinosaurs living and feeding together in groups, and this theory has been developed due to the discovery of a number of fossilized trackways containing a sequence of dinosaur footprints, all suggesting the presence of dinosaurs traveling in groups.
Though the exact lifespan of a dinosaur cannot be determined, it has been estimated that they lived quite long lives, akin to those of similar reptiles like crocodiles and turtles. Due to their slow metabolisms and herbivorous diets, these beasts have been estimated to live between 80-300 years of age.
Claosaurus dinosaurs were oviparous and reproduced by laying eggs. Their mating process was mostly similar to that of modern-day reptiles, with internal fertilization taking place inside the female's body.
The Claosaurus dinosaur had four feet, with its hind legs being strong and sturdy with the front two legs being quite small and short in comparison. It had a slender body that ended with a thick, tapering tail. It had a flat head and duck-billed mouth, like all other hadrosaurus species. Each foot had three toes and the presence of metatarsal bones was discovered as well, which was rare for such a prehistoric dinosaur. Overall, its size was quite small.
As the remains of the Claosaurus found were highly fragmented, we, unfortunately, do not have any information on how many bones this herbivore dinosaur had exactly. Though judging from the average number of bones possessed by dinosaurs, we can assume that this number is around 200.
Dinosaurs are known for their loud, earth-shaking roars which are mostly how this dinosaur communicated. They mostly used bellowing roars, grunts of low rumbling noises to communicate, in order to mate or chase away other dinosaurs from their territories. Visual displays were also probably used, with raising of the front legs, stomping, and tail whipping involved.
As far as dinosaurs go, the Claosaurus was quite small, with its length amounting to 11.5-14.8 ft (3.5-4.5 m), and its height being 5 ft (1.5 m).
Being a mostly bipedal dinosaur which was, in general, faster than other species, this dinosaur is estimated to have run at a speed of 22-25 mph (35.4-40.2 kph).
The Claosaurus dinosaur is estimated to have weighed between 1036.2-1047.2 lb (470-475 kg).
A male dinosaur has been termed a saurus whereas the female dinosaur is known as saura. However, we do not make any distinction in sex while referring to dinosaurs.
Baby Claosaurus dinosaurs were known as hatchlings.
As Claosaurus dinosaurs were herbivores in nature, they most likely sustained themselves on a diet of leaves, twigs, grass, roots, and rudimentary fruits, vegetables, and seeds.
Though herbivorous dinosaurs did not prey on smaller creatures, they still had to be quite aggressive in order to protect themselves from the larger predatory dinosaurs such as various therapods and velociraptors. They had a number of defensive mechanisms such as tough, scaly armor, bludgeon, and mace-like tails and sharp horns and spikes on their body, in order to attack any incoming predators head-on.
The name Claosaurus means broken lizard, which refers to the highly broken and fragmented state of the Claosaurus Kansas fossils when discovered.
The specimen is currently on display at the Yale Peabody Museum, where it can be viewed by budding dinosaur lovers.
This dinosaur, though being quite primitive, showed the presence of a metatarsal in its foot which other hadrosaurs did not possess. This led to the reevaluation of its species and the formation of a new genus to which this dinosaur was assigned.
There are two species in the Claosaurus genus, the Claosaurus agilis, and the Claosaurus affinis, though the existence of the second one has not been confirmed fully as yet.
All specimens of this dinosaur have been found in the United States, being in the Niobrara Formation in Kansas, the Pierre Shale Formation in Montana, and the Pierre Shale Formation in South Dakota.
The Claosaurus had four feet in total, with its hind legs being thick and its front legs being short and thin. It was bipedal in nature, choosing to run and walk exclusively on its hind feet, the only excepti0n being made while it was grazing.
The Claosaurus was first discovered in 1871 near Smoky Hill river in Kansas, North America. It was originally named Hadrosaurus agilis by Othniel Charles Marsh in 1872, being renamed as Claosaurus agilis in 1890 after new information showing the distinction between the Claosaurus and other hadrosaurs were discovered.
Here at Kidadl, we have carefully created lots of interesting family-friendly dinosaur facts for everyone to discover! Learn more about some other dinosaurs from our Martharaptor fun facts and Aucasaurus fun facts for kids pages.
You can even occupy yourself at home by coloring in one of our free printable Claosaurus coloring pages.