Diploporita

fossil echinoderm class

Written by

The Information Architects of Encyclopaedia Britannica

Last updated

June 25, 2026

Quick Summary

The Diploporita were an extinct class of echinoderms that existed from the Lower Ordovician to the Lower Devonian periods, approximately 400 to 500 million years ago. These marine invertebrates are known only from fossils.1

Key characteristics of Diploporita include:
* A globular theca (body chamber).1
* Respiratory structures consisting of pairs of pores.1

Echinoderms, as a phylum, are characterized by a skeleton made of calcium carbonate and typically exhibit five-part symmetry. While many echinoderms fossilize well, the earliest forms may have lacked calcified skeletons, contributing to gaps in the fossil record.21

Summary created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

2 Britannica Sources

Ask Britannica AI about this topic

Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.

echinoderm
Annotated classification
†Class Diploporita Lower Ordovician to Lower Devonian about 400,000,000–500,000,000 years ago; theca globular; respiratory structures pairs of pores. Subphylum Crinozoa Both fossil and living forms (Lower Ordovician about 500,000,000 years ago to Recent); with 5-part symmetry; soft parts enclosed in theca, which gives rise to 5…
Read More
†Class Diploporita Lower Ordovician to Lower Devonian about 400,000,000–500,000,000 years ago; theca globular; respiratory structures pairs of pores. Subphylum Crinozoa Both fossil and living forms (Lower Ordovician about 500,000,000 years ago to Recent); with 5-part symmetry; soft parts enclosed in theca, which gives rise to 5…
Read More