| P number: | P550288 |
|---|---|
| Caption: | Bellerophon, a primitive gastropod from the Carboniferous. |
| Description: | Bellerophon, a very primitive archaeogastropod, first evolved in the Silurian and went into extinction during the Triassic. The specimen illustrated lived in the shallow, tropical seas that covered Leicestershire in the early Carboniferous times, about 330-350 million years ago. This specimen of Bellerophon is represented here by a 'steinkern'. This is where a mould of the interior of the shell is made by water-borne minerals percolating through it, but the shell material is then dissolved away. So it is like a jelly removed from a mould. This large, planispirally coiled gastropod has rounded whorls and an umbilicus (a cavity around which the shell is coiled). Gastropods are molluscs with a muscular foot, eyes, tentacles, and a rasp-like feeding organ (a radula), although only the coiled or conical shell is fossilised. The earliest Cambrian species were marine, but gastropods now colonise fresh water and the land. Classification is based mainly on soft body parts, which are not fossilised, and although there is uncertainty, most fossils appear to fall into one of three groups: 1. Archaeogastropods which have two auricles in the heart, two gills and two kidneys. 2. Caenogastropods which have one gill, auricle and kidney and sometimes a siphon. 3. Pulmonates which have a lung. |
| Photographer: | Unknown |
| Copyright statement: | Unknown |
| Orientation: | Landscape |
| Size: | 384.13 KB; 1000 x 697 pixels; 85 x 59 mm (print at 300 DPI); 265 x 184 mm (screen at 96 DPI); |
| Average Rating: | Not yet rated |
| Categories: | Best of BGS Images/ Fossils |
Loading...
Loading...
Reviews
There is currently no feedback