Figure 2
From: Phenotypic Innovation and Adaptive Constraints in the Evolutionary Radiation of Palaeozoic Crinoids
Phylomorphospace and adaptive zone occupation. (a) Results of principal coordinate analysis conducted on the entire matrix with taxa joined according to phylogenetic relationships implied by the MCC tree. Red colors on axes represent higher values of calyx complexity and filtration fan density, blue colors indicate lower values. The first two PCO axes summarize 58.63% of the variation. Representative taxa are shown to exemplify regions of crinoid morphospace. All drawings modified from ref.42. (b) Time series of adaptive zone occupation. Taxa occurring within time bins are shown as red circles. Cyathoform taxa are distributed in the blue region on the right hand side of PCO1, whereas taxa within the two articuliform subzones are in the center and left (articuliform subzone names sensu refs30,56,57,58).
