Fixed, free, and fixed: The fickle phylogeny of extant Crinoidea (Echinodermata) and their Permian–Triassic origin - Rouse, G. W.; Jermiin, L. S.; Wilson, N. G.; Eeckhaut, I.; Lanterbecq, D.; Oji, T.; Young, C. M.; Browning, T.; Cisternas, P.; Helgen, L. E.; Stuckey, M.; Messing, C. G. (Molecular Phylogenetics and Evolution, 2013)