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A large specimen of Thamnopera reeftonensis, washed to help show its structure
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Thamnopora reeftonensis
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The genus Thamnopora is one of the most widespread and common corals from the Devonian. It is a branching, tabulate coral, with a relatively simple structure. The corallites are relatively large in Thamnopora and open perpendicular to the walls, which are very thin. This tends to give them a sponge-like appearance (see image, right). Worldwide, however, several hundred species have been defined - though some (perhaps many) of these may be synonyms so the true number of species may be much smaller.
The species found at Reefton was named Thamnopora reeftonensis by Lecompte (1949). It is fragile so, like most other corals found in the deposits there, it tends to occur as fragments that have been eroded from the parent reef, and been mixed with sediment. The growth form is therefore rarely shown. This makes identification somewhat uncertain in many cases. It is also relatively rare, so Fagerstrom and Bradshaw (2002), who studied the deposits in great detail, suggest that it was a reef-dweller - i.e. species that lived on the reef - rather than a reef-builder (a species that helped create the reef in the first place). Further Reading: Fagerstrom, J.A. & Bradshaw, M.A. 2002 Early Devonian reefs at Reefton, New Zealand: guilds, origin and paleogeographic significance. Lethaia 35, 35-50. |
Examples of Thamnopora, showing the branching habit and sponge-like structure (from the Devonian Jefferson Limestone, Kentucky, USA)
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