Postgraduate careers 2007
|
|
|
Palaeontology online access
|
|
Palaeontology volumes 1-41 (1957-99) are available online without restriction or charge.
|
|
|
From Newsletter 58:
Mystery Fossil Seven was found recently by post-graduate students in a thin section of beach rock from the Bahamas in the Leeds University Earth Sciences teaching collection. The fossil appears to be formed of calcium carbonate and is round and cog-like with eleven “spokes”. It is approximately 400 microns in diameter. The host beach rock sediment may only be a few hundreds of years old. Ideas as to its origin include calcareous green algae or holothurian plates.
Answers in an email (or, if the traditionalists prefer: on a postcard, scanned and attached to an email) to Cris Little.
Developments from Newsletter 59:
Mystery Fossil Number Seven has attracted a small flurry of e-mail activity. John Hampton at Edinburgh identified it as a very nearly horizontal section of a holothurian wheel sclerite, while Steve Donovan at the Nationaal Natuurhistorisch Museum, Leiden identified it as two fossils, with the spoked centre being a transverse section through an echinoid spine, most probably from a diadematoid, and the surrounding outer ‘vesicular’ structure being a possible algal coating on the spine. A third party was called in to adjudicate (David Pawson at the Smithsonian) and he sided with Steve’s identification. David states that the fossil is not a holothurian ossicle, firstly because it seems to have an unadorned central cavity, secondly because the rim area (with or without algae) is unlike holothurian wheels. Finally, present-day holothurians with 11-spoked wheels (Family Myriotrochidae) live mostly in bathyal/abyssal depths in the central Atlantic region; in the Arctic, one or two species venture into shallower depths. Perhaps three western Atlantic shallow-water species have wheel ossicles, and in these all of the wheels have six spokes. Echinoderms seem to be quite popular!
Created by Alan Spencer on the 2007-02-09. (Version 2.0) |
|