Explore this animal in Size of Extinct Animals ↗
429 / Paleozoic
Aegirocassis
Aegirocassis benmoulai
A two-meter filter-feeding radiodont was an early analogue of giant plankton feeders.
View original image · 1600 × 1067- Time range
- About 480 million years ago
- Final stage
- Early Ordovician
- Geographic range
- Open ocean · Morocco
01 / DEFINITION & ECOLOGY
What was Aegirocassis?
Aegirocassis (Aegirocassis benmoulai) was an extinct organism known from About 480 million years ago, with a range in Open ocean · Morocco.
Life and ecology
Comb-like frontal appendages sieved plankton while paired dorsal and ventral flaps propelled the body.
02 / DISAPPEARANCE
Why did Aegirocassis disappear?
Ordovician turnover in plankton and arthropods is possible context, but it does not establish why the genus disappeared.
03 / EVIDENCE
How do scientists know about Aegirocassis?
Three-dimensional appendages, mouthparts and body fragments reveal filtering and paired flaps.
04 / SOURCES & FURTHER READING
Check the source record
Use the scientific name to compare taxonomy, occurrence records and the fossil record. Database coverage and classifications may differ.
05 / REVISION HISTORY
How has this record changed?
- Rewrote an extinction cause that presented environmental or faunal turnover as established; it is now given as context the record does not prove.
- Verified authoritative entity sources and added three responsive reconstruction sizes.
- Initial bilingual species record published.
06 / CORRECTIONS & ADDITIONS