Research ArticlePALEONTOLOGY

Selectivity and the effect of mass extinctions on disparity and functional ecology

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Science Advances  05 May 2021:
Vol. 7, no. 19, eabf4072
DOI: 10.1126/sciadv.abf4072
  • Fig. 1 Diplobathrid diversity.

    Diplobathrid genus diversity through time calculated using the range-through method.

  • Fig. 2 Morphological and ecological disparity through time.

    (A and B) Morphological disparity. (C and D) Ecological disparity. Disparity is summarized using both sum of ranges (A and C) and sum of variances (B and D). Solid lines are mean values from 1000 bootstrap replicates, and shaded areas represent 95% confidence intervals.

  • Fig. 3 Morphospace and ecospace occupation through time.

    (A) Morphospace occupation. (B) Ecospace occupation. Occupation of morphospace and ecospace is summarized from results of principal components analyses. Each plot represents all taxa present within a time bin; spacing of time bins is not scaled to time. Mass extinction boundaries are marked by red arrows. The first two axes (shown) for morphological and ecological datasets represent 14.4% and 10.62% of the variation, respectively. See the Supplementary Materials for plots with centroid and taxon labels (figs. S5 and S6).

  • Fig. 4 Locations of diplobathrid extinction events in extinction space.

    Empirical data from diplobathrid extinctions are compared to those of lateral, random, and marginal extinctions simulated under 75% extinction intensity (23). Diplobathrid extinction events are divided into morphological and ecological datasets for both the Late Ordovician mass extinction and the Late Devonian mass extinction.

  • Table 1 Shifts in centroid for morphological and ecological data.

    Shifts in centroid are calculated between adjacent time bins with >1 taxon and between pre- and post-extinction recovery intervals (Katian versus Llandovery for the Ordovician extinction, Givetian versus Famennian for the Devonian extinction). Mean shift in centroid is 0.24 for morphology and 0.66 for ecology.

    Time bins comparedShifts in centroid,
    morphology
    Shifts in centroid,
    ecology
    Darriwilian-Sandbian0.3150.837
    Sandbian-Katian0.2870.649
    Katian-Hirnantian0.3701.001
    Hirnantian-Llandovery0.3180.920
    Llandovery-Wenlock0.2680.678
    Wenlock-Ludlow0.1950.531
    Ludlow-Pridoli0.2000.536
    Pridoli-Lochkovian0.2440.708
    Lochkovian-Pragian0.2740.676
    Pragian-Emsian0.1570.398
    Emsian-Eifelian0.1900.503
    Eifelian-Givetian0.1790.492
    Givetian-Frasnian0.3010.893
    Frasnian-Famennian0.2390.732
    Famennian-
    Tournaisian
    0.3681.074
    Tournaisian-Visean0.0000.000
    Pre-/post-Ordovician
    extinction
    0.2540.659
    Pre-/post-Devonian
    extinction
    0.3230.936
  • Table 2 Phylogenetic clustering (D) of mass extinctions summarized over 1500 time-scaled trees.

    Mean P values indicate whether extinction scenarios deviate significantly from models of random (D ≥ 1) versus BM phylogenetically structured extinction (D ≤ 0); statistically significant values indicate that the model can be rejected. The number of trees out of a sample of 1500 for which random and phylogenetic structuring models can be rejected is also given.

    Extinction
    scenario
    Mean extinct
    taxa
    Mean extant
    taxa
    Mean DSD of DMean P value,
    random
    model
    N trees
    rejecting
    random
    model
    (P < 0.05)
    Mean P value,
    BM model
    N trees
    rejecting BM
    model
    (P < 0.05)
    Ordovician:
    end-Katian
    14.94142.7392.2440.7230.92880.0111436
    Ordovician:
    end-Katian
    and
    end-
    Hirnantian
    17.13242.5431.9800.9070.95860.0091446
    Devonian:
    end-Givetian
    3.3613.989−36.5771302.1650.536200.318219
    Devonian:
    Givetian-
    Frasnian
    4.6072.914−0.27126.8070.36570.48092

Supplementary Materials

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