Kingdom Animalia Family Rotulidae Phylum Echinodermata Order Sand dollar | Class Echinoidea Species H. orbicularis Rank Genus | |
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Similar Sand dollar, Rotulidae, Encope, Dendraster, Fibularia | ||
Dakhla 2016 camp heliophora
Heliophora orbicularis is a small sand dollar in to the family Rotulidae, and the only species in the genus Heliophora. It, and other members of Rotulidae have been found in West African marine strata from the Late Miocene onward. Like the related Rotula, it is still extant.
Contents
Dakhla heliophora riders kamp 2016
Description
Individuals of H. orbicularis 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 orbicularis 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 sand dollar is present from western coast of Sahara and Senegal to Angola.