Psammodontidae is an extinct family of holocephalans (sometimes referred to as bradyodonts) known from the

Carboniferous The Carboniferous ( ) is a Geologic time scale, geologic period and System (stratigraphy), system of the Paleozoic era (geology), era that spans 60 million years, from the end of the Devonian Period Ma (million years ago) to the beginning of the ...

and

Permian The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years, from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.902 Mya. It is the s ...

periods. It is the only family of the order Psammodontiformes. The order and family are named for the type genus, '' Psammodus'', and all members are believed to have been

durophagous Durophagy is the eating behavior of animals that consume hard-shelled or exoskeleton-bearing organisms, such as corals, shelled mollusks, or crabs. It is mostly used to describe fish, but is also used when describing reptiles, including fossil t ...

nektobenthic carnivores. The only described remains assigned to Psammodontidae are isolated tooth plates.

References

Holocephali Prehistoric cartilaginous fish families {{Paleo-holocephalan-stub Carboniferous first appearances Permian extinctions Carboniferous cartilaginous fish Permian cartilaginous fish Carboniferous fish of North America