Crinoid distribution and feeding morphology through a depositional sequence: Kope and Fairview formations, Upper Ordovician, Cincinnati Arch region

Abstract

Crinoid columnals are major faunal components of interbedded shales and carbonates of the Upper Ordovician Kope to Fairview formations (Edenian-Maysvillian) of the Cincinnati Arch region. Six species can be identified on the basis of distinctive morphological characters of the columnals. Crinoid distribution was plotted from point-counted carbonate samples taken through a 68-m thick composite section of the Kope to Fairview formations in Campbell County, Kentucky. This section spans a shallowing-upward, third-order depositional sequence (C1), part of C2, and the Edenian-Maysvillian Stage boundary. The slender cladid crinoid Merocrinus occurs in the lowermost Kope below the base of this section. The slender disparids Cincinnaticrinus and Ectenocrinus occur throughout the section but are most abundant in the lower 25 m where the shale percentage is 60–90 percent. The larger, more robust disparid Iocrinus appears within the carbonate-rich Grand Avenue member of the Kope at 40–50 m, and the large, plated camerate Glyptocrinus first appears just above the Grand Avenue and becomes the dominant crinoid above the C1–C2 sequence boundary that lies just above the Kope-Fairview contact. The largest and most robust crinoid in this sequence, Anomalocrinus, occurs at the top of the Grand Avenue Member. Siliciclastic ratio and biofacies composition indicate that the occurrence of larger, more robust crinoid taxa is correlated with shallowing depth. Crinoid trophic niche differentiation is also correlated with decreasing depth and the concomitant increase in water movement caused by waves and currents. The deeper water disparids have a nonpinnulate filtration fan with low branch density and wider ambulacral grooves. The shallower water camerate Glyptocrinus has a pinnulate filtration fan with high branch density and narrower ambulacral grooves. These relationships are consistent with the predictions of aerosol filtration theory.

Testing the plateau: a reexamination of disparity and morphologic constraints in early Paleozoic crinoids

“…Morphologically, crinoid features are well represented in the skeleton, so relatively little information is lost with the decay of soft tissues (Ausich 2001). Although the crinoid skeleton requires special circumstances to be preserved intact (Donovan 1991;Brett et al 1997;Ausich 2001), many species, especially during the early Paleozoic, can be identified from disarticulated elements alone (Brower and Veinus 1974;Meyer et al 2002), and thus, taxa from environments that have lower preservation potential can be included in morphologic investigations. Even within a cohesive guild of sessile passive suspension feeders, crinoids exhibit many different features for obtaining resources (Kammer and Ausich 1987).…”

Brachiopod Shell Discoloration as an Indicator of Taphonomic Alteration in the Deep-Time Fossil Record

“…Its depositional environment has been interpreted as between storm wave base and normal wave base in the transitional or deep subtidal zone (Meyer et al, 2002). The Fairview Formation intertongues with and is overlain by the Miamitown Shale, which is dominated by medium to thick shales interbedded with thin limestones (Dattilo, 1998).…”

Deepwater occurrence of a newGlyptocrinus(Crinoidea, Camerata) from the Late Ordovician of southwestern Ohio and northern Kentucky: revision of crinoid paleocommunity composition

“…Previous citations of camerates from the Kope Formation are poorly constrained. Glyptocrinus columnals were reported from the uppermost Kope Formation (indicative of shallowing) (Meyer et al, 2002), and Pycnocrinus pattersoni (Miller, 1882) was reported by Dalvé (1948) in the lower Kope (Economy Member) (later workers, Bassler andMoodey, 1943 andWebster andWebster, 2014 re-assigned this occurrence of P. pattersoni to the sub-Kope Point Pleasant tongue of the Clays Ferry Formation [formerly Cynthiana Formation]). Although Glyptocrinus had not been reported previously from deep-water facies in the Kope Formation, Brett et al (2008b, p. 46) and Brower (2011) reported glyptocrinids from a relatively deep-water setting in the Rust Formation of New York (Katian).…”