Fig 1.
Geographic and paleogeographic locations of deep cores used in the analysis.
(A) Map of Laurussia (Euramerica) during the Wenlock age (~430 Ma) (Modified from the [26]). (B) The distribution of deep cores in conodont biofacies during the Jaani regional stage (modified from [51]). Vertical, stripe-like biofacies succession at each point represents temporal species assemblage development.
Fig 2.
Lithology, gamma-ray logs and abundance time series of conodonts in the Gėluva-99 core.
Surviving species colored in blue, victims are colored in red. Lithology legend in Fig 6.
Fig 3.
Lithology, gamma-ray logs and abundance time series of conodonts in the Ledai-179 core.
Surviving species colored in blue, victims are colored in red. Lithology legend in Fig 6.
Fig 4.
Lithology, gamma-ray logs and abundance time series of conodonts in the Butkūnai-241 core.
Surviving species colored in blue, victims are colored in red. Lithology legend in Fig 6.
Fig 5.
Lithology, gamma-ray logs and abundance time series of conodonts in the Jačionys-299 core.
Surviving species colored in blue, victims are colored in red. Lithology legend in Fig 6.
Fig 6.
Lithology, gamma-ray logs and abundance time series of conodonts in the Tverečius-336 core.
Surviving species colored in blue, victims are colored in red.
Fig 7.
Frequency distribution of samples as a function of values of environmental proxy (gamma-ray intensities at sampling sites ≈ amount of clayey and organic material in a rock).
Fig 8.
Logistic regression models that include the best predictors of conodont survival during the Ireviken event.
(A) Skewness of species abundance distributions (G(a)); (B) Spectral exponents (ν) calculated from the longest stratigraphic abundance series for a given species; (C) Average gamma-ray values () at the positive sample sites for a given species. Equation abbreviations: P, probability of survival, β, logistic variable regression coefficient (log-odds of survival), Pβ = 0, the probability that coefficient is β equal to zero. Frequency distributions (E-F) of victims and survivors with estimates of their average values of predictors and the results of Student’s t-test for equality of means: (E) Skewness of species abundance distributions (G(a)); (F) Spectral exponents (ν); Average gamma-ray values (
) at the positive sample sites.
Table 1.
A comparison of complex logistic models (based on n = 29 observations) of conodont species survival probability during the Ireviken event.
Models are compared and ranked based on AICc and associated Akaike weight (ω) values.
Table 2.
Statistical estimates of the best multivariable logistic model.
Fig 9.
Regression tree model revealing factors associated with conodont species survival during the Ireviken event.
Estimated probabilities of survival (P) and corresponding numbers of species (n) at each node are positioned in circular arrangements, and corresponding survival probabilities and species numbers at terminal branch tips form square-shaped arrangements. Symbol abbreviations: () average gamma ray values at the positive sample sites, (G(a)) skewnesses of species abundance distribution, (E(t)) apparent extirpation rates.