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Un-named Crinoids
Order: Crinoid
Genus: Not known Species: Not known Location found: Upper Takaka Valley, Nelson Region |
This specimen (and one in image below, right) was found in the Upper Takaka Valley, in the southern of Golden Bay, north-west of Nelson. It comprises a large number of crinoid fragments (seen as the pale features) set within a piece of hard, black marble from the Arthur Marble formation.
Crinoids belong to the phylum Echinodermata, which also include sea urchins and starfish. Modern crinoids may be stalked (known as sea lilies) or unstalked (known as feather stars). A beautiful depiction of a sea lily was drawn by the German zoologist and artist, Ernst Haeckel (see below, left). Today, crinoids live in a range of marine environments, from shallow seas to deep marine trenches up to 9000 metres deep.
The specimens shown may contain fragments from more than one species of crinoid, but a firm identification has not yet been made. The fragments also come from various parts of the organism. The stem of crinoids is formed of circular ossicles, and in fossils these are often preserved either individually or in short sections of stem. The ossicles are porous to allow nutrients to pass through the organism, and in cross-section they can thus be seen to enclose a hollow area at the centre. In different species, this hollow core has different shapes, and is a guide to identification. If you zoom into the image above, a clear ossicle with a five-point star-shaped centre can be seen in the lower right corner. Other ossicles mainly show hexagonal centres, often somewhat distorted by crushing during fossilisation and later compression of the rock.
Additional ossicles occur at the base of the cup-like feature from which the feathery arms extend. Again, these may take different forms in different species. An example can be seen in the picture below right (the large six-pointed picture near the centre). The longer, toothed features are probably long-sections of arms or stems.
Crinoids belong to the phylum Echinodermata, which also include sea urchins and starfish. Modern crinoids may be stalked (known as sea lilies) or unstalked (known as feather stars). A beautiful depiction of a sea lily was drawn by the German zoologist and artist, Ernst Haeckel (see below, left). Today, crinoids live in a range of marine environments, from shallow seas to deep marine trenches up to 9000 metres deep.
The specimens shown may contain fragments from more than one species of crinoid, but a firm identification has not yet been made. The fragments also come from various parts of the organism. The stem of crinoids is formed of circular ossicles, and in fossils these are often preserved either individually or in short sections of stem. The ossicles are porous to allow nutrients to pass through the organism, and in cross-section they can thus be seen to enclose a hollow area at the centre. In different species, this hollow core has different shapes, and is a guide to identification. If you zoom into the image above, a clear ossicle with a five-point star-shaped centre can be seen in the lower right corner. Other ossicles mainly show hexagonal centres, often somewhat distorted by crushing during fossilisation and later compression of the rock.
Additional ossicles occur at the base of the cup-like feature from which the feathery arms extend. Again, these may take different forms in different species. An example can be seen in the picture below right (the large six-pointed picture near the centre). The longer, toothed features are probably long-sections of arms or stems.