Kingdom Animalia
Phylum Chordata
Superclass Tetrapoda
Class Amphibia
Order Temnospondyli
Suborder Stereospondyli
Family Mastodonsauridae
Genus Mastodonsaurus
1st Species Mastodonsaurus jaegeri
2nd Species Mastodonsaurus giganteus
3rd Species Mastodonsaurus torvus
Other attributes
Time Range 242-235 mya
Location Germany, United Kingdom, Russia
Name Meaning Breast tooth reptile
Physical Dimensions 6.2 meters long for M. giganteus
Weight 2.1 tonnes for M. giganteus
Dietary Classification Carnivore
Mastodonsaurus is a mastodonsaurid temnospondyl amphibian from the Middle-Late Triassic of Germany, the United Kingdom, and Russia. It was named in 1828 by Georg Friedrich von Jaeger. It was the earliest described temnospondyl, and was also one of the most unique.


Mastodonsaurus resembled a mix between a frog, a salamander, and a crocodile. It had 4 legs, a long tail similar to that of a tadpole, a bulky body, a big, semi-flat head with big jaws, and eyes on the top of its head. However, it had one difference; at the very front of its jaws, it had a pair of large, tusk-like teeth that were so big that they could only be hidden from the air through small holes near its nostrils. Its body would have been covered in smooth skin.


Mastodonsaurus was a predator, preying on fish, small reptiles, and smaller amphibians. Its huge, tusk-like teeth were used for getting a hold of struggling prey; as well as this, it had a second set of teeth behind its huge jaws, mainly for capturing prey and ensuring it did not escape.


Unlike other temnospondyl amphibians, which were capable of moving around on land, Mastodonsaurus was fully aquatic, only using its limbs to navigate around dense weeds and underwater obstacles; this comes from the fact that its head was massive (making it really front-heavy), and its limbs were relatively weak. Another discovery that confirms this is the massive bone beds that have shown that Mastodonsaurus individuals died en masse when pools dried up during deadly droughts. As well as this, Mastodonsaurus lived in swamps and ate fish, capturing them with its massive jaws and large tusks; it also may have preyed on smaller amphibians, depending on whether or not the toothmarks on other amphibians made by it are evidence of predation. Even though it wouldn't have been able to go on land, it may even have ambushed small archosaurs standing by the water's edge.

In popular cultureEdit

Mastodonsaurus was one of the 1st Mesozoic animals discovered, so it was featured in Crystal Palace Park (a pleasure ground in London) as a giant, frog-like amphibian. Despite its prevalent perception at the time, it was overshadowed by the giant reptiles featured alongside it, such as Iguanodon, Megalosaurus, Mosasaurus, Pterodactylus, Plesiosaurus, and Ichthyosaurus.

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