Fig 1.
Norian to Pliensbachian extinction and origination percentages and number of boundary crossers for the class Gastropoda and the main subclasses considered in the analysis.
A, origination and extinction percentages and boundary crossers for the class Gastropoda. The dotted line shows the change of extinction magnitude (%) across the studied time interval. Values in brackets are based on ‘observed within-bin diversity’ and the rest of values on ‘inferred within-bin diversity’. B, origination and extinction percentages and boundary crossers for the subclass Heterobranchia. C, origination and extinction percentages and boundary crossers for the subclass Caenogastropoda. D, origination and extinction percentages and boundary crossers for the subclass Vetigastropoda. E, origination and extinction percentages and boundary crossers for the subclass Neritimorpha.
Table 1.
Summary of data.
Fig 2.
Extinction and origination percentages and boundary crossers of bivalve genera from the Norian–Sinemurian.
A, B, all genera; C, D, Pteriomorphia; E, F, Heteroconchia.
Fig 3.
Percentage of completeness (SCM) of the gastropod fossil record during the T-J boundary.
A, SCM of the Class Gastropoda. B, SCM of Heterobranchia. C, SCM of Caenogastropoda. D, SCM of Vetigastropoda. E, SCM of Neritimorpha. See text for details.
Table 2.
Chi square test statistics for differences in extinction magnitude among gastropod subclasses.
Fig 4.
Palaeobiogeographical map showing the pre-extinction distribution of the main gastropod subclasses during the Late Triassic (Norian-Rhaetian; 227–201.3 Ma).
Subclasses, the number of genera referred to each subclass, and the palaeobiogeographical regions without members of Heterobranchia are indicated (Data: S3 Table).
Fig 5.
Shell size (box plot) of Cylindrobullina during the Triassic–Jurassic transition.
Note the increase in shell size (height in mm) from the Norian–Rhaetian to the Pliensbachian. Horizontal lines: mean; boxes: 25–75 percent quartiles; vertical lines: minimum and maximum values.