''Calclamnoidea'' is an extinct genus of

sea cucumber Sea cucumbers are echinoderms from the class Holothuroidea (). They are marine animals with a leathery skin and an elongated body containing a single, branched gonad. Sea cucumbers are found on the sea floor worldwide. The number of holothu ...

which existed in

Poland Poland, officially the Republic of Poland, , is a country in Central Europe. Poland is divided into Voivodeships of Poland, sixteen voivodeships and is the fifth most populous member state of the European Union (EU), with over 38 mill ...

during the

Triassic The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago (Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period ...

period.Triassic Holothurian Sclerites from Tatra Mountains
Krystyna Zawidzka.

References

Fossils of Poland Calclamnidae Prehistoric sea cucumber genera Triassic echinoderms Middle Triassic first appearances Late Jurassic extinctions Fossil taxa described in 1955 {{Paleo-holothuroidea-stub