Abstract
ABSTRACTCrinoids are diverse and well-known from the Permian of Timor, but the literature has failed to document the numerous specimens of crinoid pluricolumnals from the fauna, many showing unusual morphology or yielding palaeoecological information. A curious and instructive specimen demonstrates the relationship between a living Permian crinoid and coeval invasive, pit-forming, invertebrates in detail. The pit-former is not preserved; most likely it was unmineralized or, if mineralized, then the shell simply dropped out. The infesting organism made pits assigned to the ichnospecies Oichnus paraboloides Bromley. The pit-former was unusually site selective. Either (1) one spatfall attached to just one side of the elevated (either up-current or down-current) or recumbent column and each individual centered their pits on the sutures between adjacent columnals; or (2) a single individual migrated along the column. The living crinoid showed an extreme reaction to this infestation. Excess stereom growth on the side of the pits transformed what was a circular column by addition of a thick, triangular ridge on the pitted side.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
