Kingdom Animalia
Phylum Chordata
Superclass Tetrapoda
Class Reptilia
Subclass Diapsida
Order Placodontia
Family Placodontidae
Genus Placodus
1st Species Placodus gigas
2nd Species Placodus inexpectatus
Other attributes
Time Range 245-235 mya
Location Germany, France, Poland, China
Name Meaning Tablet tooth
Physical Dimensions 2 meters long
Dietary Classification Carnivore

Placodus is a placodontid placodontian reptile from the Middle-Late Triassic of Germany, France, Poland, and China. It was named in 1833 by Louis Agassiz. It was a unique reptile, as unlike the other reptiles of its time (which caught fish with their sharp), it crushed mollusks with flat teeth.


Placodus resembled a marine iguana, with a broad body, short legs, a long tail, and a small head with small jaws. However, it had a few major differences; for example, instead of having sharp teeth all over its jaws, it had laterally compressed incisors at the front of its jaws, while flattened teeth were present at the back of its jaws. Its body was covered in scaly skin, with a row of crocodile-like scutes running down its back.


Placodus was a predator, preying on bivalves. At the front of its jaws, it had chisel-like incisors designed for picking bivalves off the seafloor, while at the back of its jaws (and the roof of its mouth), it had flattened teeth designed for crushing them.


Due to its dense bones and heavy armor, Placodus could sink without trying to keep a light, air-filled body, and so, it would have had no problem staying near the seafloor to feed. As well as this, when swimming, it moved its tail from left to right, while its legs were used to steer itself by pushing against the water; however, this method of swimming meant that it could not venture out into the open ocean, and only stayed near the seashore. As well as this, its short legs did allow it to clamber onto land; however, due to the fact that they weren't really strong, it had to drag itself across the ground in a similar manner to turtles. While feeding, Placodus used its legs to float in the water while picking shellfish off the seafloor; as well as this, a parietal eye would have helped the reptile orient itself correctly when it needed to return to the surface, which would be especially useful when floating face down near the seafloor.

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