Ordovician_Odyssey Posted August 20, 2013 Share Posted August 20, 2013 Hey guys, I have recently been interested in finding a rhyncholite (fossil cephalopod beak). Has anyone heard of these being present in Ordovician material? Thank you very much for the help! Cheers, Shamus -Shamus The Ordovician enthusiast. Link to comment Share on other sites More sharing options...
piranha Posted August 20, 2013 Share Posted August 20, 2013 Hi Shamus, There is one possible occurrence reported from the late Ordovician. None of the subsequent reviews sunk the discovery, but you might have a difficult time finding another Ordovician example! Alexander, R.R. (1986) Resistance to and repair of shell breakage induced by durophages in Late Ordovician brachiopods. Journal of Paleontology, 60(2):273-285 Additional evidence that incriminates the orthoconic nautiloids as the durophage that injured the late Ordovician brachiopods is the preservation of an apparent rhyncholite (calcareous upper cephalopod jaw element) imbedded in the valve of Rafinesquina alternata (Fig. 8). "All observable features of this specimen (shape, proportions, laminations, and composition) are comparable with rhyncholite morphology" (W.B. Saunders). If identification is corroborated, this imbedded rhyncholite is the oldest calcified upper jaw element of a cephalopod. The oldest occurrence previously known is in the Triassic (Saunders et al., 1978). Link to comment Share on other sites More sharing options...
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