Resolving Details of the Nonbiomineralized Anatomy of Trilobites Using Computed Tomographic Imaging Techniques
Remains of two trilobite species, Elrathia kingii from the Wheeler Formation (Cambrian Series 3), Utah, and Cornuproetus cornutus from the Hamar Laghdad Formation (Middle Devonian), Alnif, Morocco, were studied using computed tomographic (CT) and microtomographic (micro-CT) imaging techniques for evidence of nonbiomineralized alimentary structures. Specimens of E. kingii showing simple digestive tracts are complete dorsal exoskeletons preserved with cone-in-cone concretions on the ventral side. Inferred stomach and intestinal structures are preserved in framboidal pyrite, likely resulting from replication by a microbial biofilm. C. cornutus is preserved in non-concretionary limestone with calcite spar lining the stomach ventral to the glabella. Neither species shows sediment or macerated sclerites of any kind in the gut, which tends to rule out the possibilities that they were sediment deposit-feeders or sclerite-ingesting durophagous carnivores. Instead, the presence of early diagenetic minerals in the guts of E. kingii and C. cornutus favors an interpretation of a carnivorous feeding strategy involving separation of skeletal parts of prey prior to ingestion.
Paleontology, Paleoecology, trilobite, digestive anatomy, Elrathia kingii, Cornuproetus cornutus, Cambrian, Wheeler Formation, Hamar Laghdad Formation, exceptional preservation
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