Figure 1.
Holes generated by tumbling experiments on various shells.
(A) Brachiopod shell (Frenulina sanguinolenta) (GIUS 12-3616/Fs1) after 4 hours of tumbling. (B) Unionidae bivalve shell (GIUS 12-3616/U1) after 1 hour of tumbling. (C–D) Gastropod shells (Nassarius sp.) (GIUS 12-3616/N1-2) after 2 hours of tumbling. (E–F) Close up of hole margins in Nassarius sp.
Figure 2.
Two morphotypes of the inner outlines of holes and their frequency distribution (drawings by camera lucida).
Figure 3.
Projections of hole margins at vertical cross sections.
Figure 4.
Scatter plots showing two types of correlations.
(A) Correlation between hole size and shell size. (B) Correlation between the inner and outer hole diameter in Nassarius sp. Symbols for (A): r–Spearman rank correlation, p–probability of Type I Error for H [0]: r = 0, n–sample size.
Table 1.
Results of tumbling experiments on various shells.
Figure 5.
Frequency distribution of holes in Nassarius sp.
(A) Apertural view. (B) Abapertural view.