P550159

Uploaded on:
2009-03-17 22:31:11.0
Type:
Digital Asset
File Size:
426.27 KB
Dimensions:
563 x 1000 pixels
4037 views 16 downloads
P number: P550159
Caption: Charnia masoni, a fossil coral.
Description: Charnia is a rather enigmatic fossil that resembles a sea pen, considered by some to be an octacoral. The illustrated specimen was found in volcanic ash that was ejected from a volcano late in the Precambrian, about 600 million years ago. It is soft-bodied, so only an impression of the organism can be found in the fine-grained rocks (the illustration shows a plaster cast). They have been found as far apart as Leicestershire, England, and Australia. Charnia masoni has a leaf-shaped frond which stands up from the sediment of the sea floor on a short stalk. Some specimens have a disk-like structure that appears to act as a holdfast (called Charniodiscus). Each frond has numerous (up to about 50) branches which extend out each side of the organism and bearing the polyps during life. This species is Britain's oldest animal. Octacorals form a subclass of the corals which has a poor fossil record. Sea pens are apparently represented in the late Precambrian, possibly in the Silurian but otherwise they are known only in the Recent. The skeleton of modern Octacorals is made of horny or calcareous material and the polyps have eight tentacles and eight radiating partitions.
Photographer: Unknown
Copyright statement: NERC
Orientation: Portrait
Size: 426.27 KB; 563 x 1000 pixels; 48 x 85 mm (print at 300 DPI); 149 x 265 mm (screen at 96 DPI);
Average Rating: Not yet rated
Categories: Best of BGS Images/ Fossils  

Reviews

There is currently no feedback