Heliophora
| Heliophora Temporal range: 9 –0 Ma Late Pliocene to Recent | |
|---|---|
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| Fossils of Heliophora species. Pliocene of Maroc | |
| Scientific classification | |
| Domain: | Eukarya |
| Kingdom: | Animalia |
| Phylum: | Echinodermata |
| Class: | Echinoidea |
| Subclass: | Euechinoidea |
| Superorder: | Gnathostomata |
| Order: | Clypeasteroida |
| Family: | Rotulidae |
| Genus: | Heliophora Agassiz 1840 |
Heliophora is a genus of small sand dollars belonging to the family Rotulidae.
Species
- Heliophora orbicularis (Linnaeus, 1758)
- Heliophora orbiculus (Linnaeus, 1758)
Description
Heliophora are very distinctive in appearance and also highly morphic, with a remarkable diversity in individual specimens. This genus has an extremely variable circular to oval-shaped test. The indentations may remain restricted to the posterior edge or may be found along the entire margin of the test. The indentations may be very shallow or quite deep, forming long "fingers," or digits. The digits are very fragile, and prone to breaking off.
Ecology and Feeding
Heliophora live in large groups in very shallow water of lagoons and estuaries, usually lightly buried in mud.
Food particles are picked out of the substrate by the tube feet, and are maneuvered into the food grooves along the oral side of the test, which are underneath the digits of the test. Once placed into a food groove, food particles are caught in a string of mucus and moved into the mouth, which is located in the very center of the oral side of the test.
Distribution
This genus is present from western coast of Sahara and Senegal to Angola.
References
- Schultz, Heinke (2006) Sea Urchins I: a guide to worldwide shallow water species Heinke + Peter Schultz Partner Scientific Publications ISBN 3-9809868-2-9; Sea Urchins
- Treatise on Invertebrate Paleontology Part U, Volume 2 1966
- Mortensen, T. 1948. A Monograph of the Echinoidea IV.2 Clypeasteroida. C. A. Reitzel, Copenhagen.