Cupulocrinus humilis

This sea lily was collected from the Bobcaygeon Formation in Ontario Canada. This rock unit has produced many crinoid fossils, and this species is one of the most common. Its arms formed an open-fan system of large area and low filtration density (Cole et al., 2019), with a stalk long enough to be part of the intermediate tier of suspension feeders above the substrate. There has been some uncertainty about the classification of Cupulocrinus, but Wright et al. (2017) suggested including it within the Flexibilia, a group of cladid crinoids.

References:

Cole, S.R., Wright, D.F. and Ausich, W.I., 2019. Phylogenetic community paleoecology of one of the earliest complex crinoid faunas (Brechin Lagerstätte, Ordovician). Palaeogeography, Palaeoclimatology, Palaeoecology, 521, pp.82-98. DOI: https://doi.org/10.1016/j.palaeo.2019.02.006.

Wright, D.F., Ausich, W.I., Cole, S.R., Peter, M.E. and Rhenberg, E.C., 2017. Phylogenetic taxonomy and classification of the Crinoidea (Echinodermata). Journal of Paleontology, 91(4), pp.829-846. DOI: https://doi.org/10.1017/jpa.2016.142.