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Perischoechinoidea

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Perischoechinoidea is a subclass of primitive sea urchins that were abundant in the Palaeozoic seas. However, the great majority of species died out during the Mesozoic, as the more advanced euechinoid sea urchins became common. Today, only a single order, the Cidaroida, survives.

Wikidata facts

Instance of
monotypic taxon
Parent taxon
Echinoidea
Image
Cidaris cidaris MHNT.jpg
Show 2 more facts
taxon name
Perischoechinoidea
taxon rank
subclass
Sources (1)

via Wikidata · CC0

~1 min read

Encyclopedic overview

2 sections
Contents
  • Taxonomy
  • References

Perischoechinoidea is a subclass of primitive sea urchins that were abundant in the Palaeozoic seas. However, the great majority of species died out during the Mesozoic, as the more advanced euechinoid sea urchins became common. Today, only a single order, the Cidaroida, survives.

Most fossil forms had multiple columns of ambulacral plates, rather than the two rows found in all living species of sea urchin. They also lacked a perignathic girdle around the mouth.

Excerpted from Wikipedia’s “Perischoechinoidea” article, available under the CC BY-SA 4.0 licence.