spatangoida

"Sea Potato" (Echinocardium cordatum)

…a species of Loveniid sea urchin which boasts a mostly cosmopolitan distribution. Where it occurs in temperate seas in the north Atlantic, west Pacific, around Australia and New Zealand, as well as South Africa. Sea potatoes are often seen on sandy sea beds, where they will bury themselves constructing small burrows which are lined by mucus secretions. Detritus and other nutrients will collect on these secretions, and made their way to the central area of the burrow, where the sea potato will feed on them. Sea potato burrows are known to house a wide range of commensals, especially the bivalve Tellimya ferruginosa.

Classification

Animalia-Echinodermata-Echinoidea-Spatangoida-Loveniidae-Echinocardium-E. cordatum

Image: Hans Hillewaert

Fossil Sea Biscuits

These sea biscuits are fossil of the extinct species Lovenia woodsii (Spatangoida - Loveniidae), recorded from the Lower to Middle Miocene of Australia.

Left specimen is 1.4 inches tall, and right specimen is 1.2 inches tall.

References: [1] - [2]

Photo credit: ©Stan Celestian

Locality: Beaumoris, Victoria, Australia

Name: Hemiaster
Location: Texas, USA, Kiamichi Formation
Age: 100-113 million years ago, Cretaceous Period

The star (in blue) in the photograph is a clue to a circuitous history of descent. Early ancestors of irregular sea urchins had two-part bodies. Later generations had five-part bodies. Even later generations had new two-part bodies, like the specimen of Hemiaster in the photograph.

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Spatangus purpureus

…is a species of spatangid heart urchin that occurs throughout the entire North Sea and is distributed from the North Cape to the Azores and the Mediterranean. S. purpureus typically inhabits bottoms with coarse sand or gravel. From there it spends its live burrowed, collecting detritus that calls near it.

Classification

Animalia-Echinodermata-Echinoidea-Atelostomata-Spatangoida-Spatangidae-Spatangus-S. purpureus

Images: Hans Hillewaert and Roberto Pillon