Fig 1.
Phylogeny of main Jurassic echinoid clades.
Phylogenetic relationships between clades and estimated times of divergence (in millions of years) are based on Kroh and Smith [73]. Clades are a mix of higher taxonomic ranks. Crosses indicate extinct clades. The green area corresponds to the studied time interval. Ages in millions of years Before Present (after Gradstein et al. [74]).
Fig 2.
Landmarks (red dots) are positioned at the junction between the perradial suture lines (central line of each ambulacrum) and the peristome edge (five inner landmarks) and between the perradial suture lines and the ambitus (five outer landmarks). Roman numerals refer to the echinoid’s five ambulacra.
Fig 3.
Taxonomic diversity and disparity of Jurassic echinoids.
Individual contribution of echinoid clades to total taxonomic diversity and disparity levels for the studied time period. Colored areas show the values for irregular echinoid clades. Areas in white and grey are for regular echinoid clades. Poly: Polycidaridae, Cid: Cidaridae, Aulo: Aulodonts, Hemi: Hemicidaridae, Ps: Pseudodiadematidae, Cal: Calycina, Ech: Echinacea, Orth: Orthopsidae, Eo: Eognathostomata, Deso: Desorellidae, Neo: Neognathostomata, Atelo: Atelostomata.
Fig 4.
Morphospace plot of echinoid disparity.
Black symbols correspond to the specimens of regular echinoids, yellow, blue, green, and red symbols represent irregular echinoids. Outlines shown for representative specimens among Cidaridae, Eognathostomata, Desorellidae, Neognathostomata, and Atelostomata. Poly: Polycidaridae, Cid: Cidaridae, Aulo: Aulodonts, Hemi: Hemicidaridae, Ps: Pseudodiadematidae, Cal: Calycina, Ech: Echinacea, Orth: Orthopsidae, Eo: Eognathostomata, Deso: Desorellidae, Neo: Neognathostomata, Atelo: Atelostomata.
Fig 5.
Richness and disparity levels of main Jurassic echinoid clades in relation with their feeding strategies and modes of life.
The spindle diagram shows taxonomic diversity and disparity levels for the 12 Jurassic echinoid clades. For each clade, taxonomic diversity is expressed as species richness for each geological stage, the wider the rectangles, the higher the number of species. Colors correspond to the tested disparity values relative to other clades: unusually high (red), normal (orange), unusually low (yellow), not tested due to lack of data (white). Main feeding strategies and modes of life were interpreted for each clade. Ages in million of years Before Present (after Gradstein et al. [73]).
Fig 6.
Biplot of species richness and disparity.
Species richness (expressed in number of species) is plotted against disparity (expressed as the Mean Pairwise Distance) for each clade and each time interval. The four clades of irregular echinoids are plotted separately from the others (respectively A and B).