Lingulasma tenuigranulata - Palaeoecology of a large Ordovician linguloid that lived within a strophomenid-trilobite community (original) (raw)

Pickerill, R. K., 1973. Lingulasma tenuigranulata -Palaeoecology of a large Ordovician linguloid that lived within a strophomenid-trilobite community. Palaeogeogr., PalaeoclimatoL, Palaeoecol., All the specimens of Lingulasma tenuigranulata found at two localities in Meifod, Montgomeryshire (North Wales), are in original life position, with the burrow attitudes ranging from vertical, inclined and vertical oblique to inclined oblique. The specimens are all extremely large in size for linguloids (over 3.9 cm in length) and this is attributed essentially to an abundant food supply and possibly to vertical phosphate diffusion within the enclosing sediments. The unimodal size-distribution is attributed to an absence of predation and disease and to death by senility. The associated fauna shows that Lingulasma is part of a strophomenid-trilobite community rather than the normally expected gastropod-bivalve one. The trophic structure of this community is shown to be out of accord with that of recent communities. L. tenuigranulata represented chance spatfalls in an open shelf '~wir~gnment which was extremely conducive~to its growth and development.