Tetragonosaurus Facts
Pronunciation: tet-RAG-oh-no-SORE-us
Name meaning: Four-angled lizard
| Diet | Herbivore |
| Height | 2m |
| Length | 6m |
| Weight | 1.5 tonnes |
| Speed | 25 km/h |
| Environment | Land |
| Era | Cretaceous |
| Period | Late Cretaceous |
| Type | Ornithopod |
| Location | North America |
Tetragonosaurus was originally described as a distinct genus of ornithopod dinosaur from the Late Cretaceous period, approximately 83.6 million years ago. However, modern scientific analysis has revealed that the fossils attributed to Tetragonosaurus actually represent juvenile specimens of Lambeosaurus, a well-known crested duck-billed dinosaur from western North America.
When first discovered in Alberta, Canada, these fossils appeared different enough from adult Lambeosaurus specimens to warrant their own genus classification. The name 'Tetragonosaurus' meaning 'four-angled lizard' was given due to the distinctive shape of certain skull elements. These ornithopod dinosaurs would have been plant-eaters, using their sophisticated dental batteries to grind tough vegetation.
As juvenile Lambeosaurus, these dinosaurs would have grown into magnificent crested ornithopods, developing the characteristic hollow head crest that adult Lambeosaurus are famous for. The young animals likely lived in herds alongside their parents, learning to navigate the lush coastal plains and river deltas of Late Cretaceous North America.
This reclassification demonstrates how our understanding of dinosaur growth and development has advanced significantly since the early days of palaeontology, when juvenile and adult specimens of the same species were often mistaken for entirely different animals.
What made Tetragonosaurus distinctive?
As juvenile Lambeosaurus, Tetragonosaurus specimens showed the characteristic duck-like bill of ornithopod dinosaurs but lacked the prominent hollow crest of adults. The skull elements displayed a distinctive four-angled shape that initially led scientists to classify them as a separate genus.
Behaviour
As young ornithopods, these dinosaurs likely stayed close to adult herds for protection and learning. They would have been capable of both bipedal and quadrupedal locomotion, switching between gaits as needed for feeding or escaping predators.
Tetragonosaurus FAQ
What did Tetragonosaurus eat?
As juvenile
Lambeosaurus, Tetragonosaurus would have been herbivorous, feeding on ferns, conifers, and flowering plants. Young ornithopods likely ate softer vegetation than adults, as their dental batteries were still developing.
How big was Tetragonosaurus?
The specimens attributed to Tetragonosaurus were approximately 6 metres long, 2 metres tall at the hip, and weighed around 1.5 tonnes. These measurements represent juvenile animals that would have grown much larger as adults.
When did Tetragonosaurus live?
Tetragonosaurus lived during the
Late Cretaceous period, approximately 83.6 million years ago, in what is now western North America during a time of warm, humid climate.
Where was Tetragonosaurus found?
Tetragonosaurus fossils were discovered in Alberta, Canada, in rock formations that have yielded numerous other
Late Cretaceous dinosaur specimens from the region.
How do you pronounce Tetragonosaurus?
Tetragonosaurus is pronounced 'tet-RAG-oh-no-SORE-us', with emphasis on the second syllable. The name breaks down as 'tetragon' (four-sided) and 'saurus' (lizard).
What does Tetragonosaurus mean?
Tetragonosaurus means 'four-angled lizard' in Greek, referring to the distinctive four-sided shape of certain skull elements that were observed in the original fossil specimens.
How fast could Tetragonosaurus run?
As juvenile ornithopods, these dinosaurs could likely reach speeds of around 25 km/h when running on their hind legs, useful for escaping predators or keeping up with adult herds.
What type of dinosaur was Tetragonosaurus?
Tetragonosaurus was classified as an ornithopod dinosaur, specifically a member of the Hadrosauridae family. However, it is now considered to represent juvenile specimens of
Lambeosaurus rather than a distinct genus.
Was Tetragonosaurus related to birds?
As an ornithopod dinosaur, Tetragonosaurus was more distantly related to birds than theropod dinosaurs. However, all dinosaurs, including ornithopods, share a common ancestor with modern birds.
How many Tetragonosaurus fossils have been found?
Only a small number of specimens were originally attributed to Tetragonosaurus before they were reclassified as juvenile
Lambeosaurus. The exact count is unclear as these fossils are now studied as part of Lambeosaurus collections.
