TABLE 1. Principal component axes, singular values, percent variation, cumulative percentage and associated variables for the entire sample of 120 lamniform shark teeth. To better compare the two approaches, the associated variables detected in Marramà and Kriwet (2017) are also reported. Only the first three axes (in bold) are considered for this analysis. The asterisk (*) indicates those variables that were not considered significantly correlated to the same axis in Marramà and Kriwet (2017) (i.e., |loading| ≤ 0.5).
| PC | SV | % Variance | Cumulative % | Associated variables detected through geometric morphometrics |
Associated variables detected in Marramà and Kriwet (2017) through traditional morphometrics |
| 1 | 1.13973 | 50.42% | 50.42% | BCW, DS, HCW*, LCW*, PCH*, PCW, RA, RH*, RW | BCW, DS, PCW, RA, RW |
| 2 | 0.56078 | 12.21% | 62.62% | BCW, LCH, LCW, PCH*, RA, RH*, RW | BCW, LCH, LCW, RA, RW |
| 3 | 0.55516 | 11.96% | 74.59% | CH, DCL, DS*, HCW, IDCE*, IMCE, MCL, RA*, RH, RW* | CH, DCL, HCW, IMCE, MCL, RH |
| 4 | 0.48118 | 8.99% | 83.58% | ||
| 5 | 0.35182 | 4.80% | 88.38% | ||
| 6 | 0.28161 | 3.08% | 91.45% | ||
| 7 | 0.25149 | 2.45% | 93.91% | ||
| 8 | 0.17997 | 1.26% | 95.17% | ||
| 9 | 0.17442 | 1.18% | 96.35% | ||
| 10 | 0.15596 | 0.94% | 97.29% | ||
| 11 | 0.13397 | 0.70% | 97.99% | ||
| 12 | 0.11575 | 0.52% | 98.51% | ||
| 13 | 0.10176 | 0.40% | 98.91% | ||
| 14 | 0.09143 | 0.32% | 99.23% | ||
| 15 | 0.07999 | 0.25% | 99.48% | ||
| 16 | 0.06671 | 0.17% | 99.65% | ||
| 17 | 0.05771 | 0.13% | 99.78% | ||
| 18 | 0.05269 | 0.11% | 99.89% | ||
| 19 | 0.03199 | 0.04% | 99.93% | ||
| 20 | 0.02449 | 0.02% | 99.95% | ||
| 21 | 0.01884 | 0.01% | 99.97% | ||
| 22 | 0.01670 | 0.01% | 99.98% | ||
| 23 | 0.01539 | 0.01% | 99.99% | ||
| 24 | 0.01186 | 0.01% | 99.99% | ||
| 25 | 0.00963 | 0.00% | 100.00% | ||
| 26 | 0.00744 | 0.00% | 100.00% |
TABLE 2. Results of the non-parametric PERMANOVA and ANOSIM tests for all the possible pairwise comparisons between the four genera on the overall sample of 120 specimens. Euclidean distances are chosen as a measure unit. The asterisks (*) indicate significant comparisons (p < 0.05) thereby suggesting that groups exhibit considerably different morphospace occupations.
| PERMANOVA | ||||
| p-values | Brachycarcharias | Carcharias | Carcharomodus | Lamna |
| Brachycarcharias | 0.0011* | 0.0482* | 0.0005* | |
| Carcharias | 0.0017* | 0.0001* | ||
| Carcharomodus | 0.0013* | |||
| Lamna | ||||
| F-values | ||||
| Brachycarcharias | 8.975 | 2.844 | 6.913 | |
| Carcharias | 8.573 | 18.92 | ||
| Carcharomodus | 5.345 | |||
| Lamna | ||||
| ANOSIM | ||||
| p-values | Brachycarcharias | Carcharias | Carcharomodus | Lamna |
| Brachycarcharias | 0.0136* | 0.0474* | 0.0001* | |
| Carcharias | 0.0034* | 0.0001* | ||
| Carcharomodus | 0.0005* | |||
| Lamna | ||||
| R-values | ||||
| Brachycarcharias | 0.1360 | 0.1784 | 0.3448 | |
| Carcharias | 0.3212 | 0.4095 | ||
| Carcharomodus | 0.3658 | |||
| Lamna |
TABLE 3. Principal component axes, singular values, percent variation, cumulative percentage and associated variables for the sample of Brachycarcharias and Lamna. Only the first two axes (in bold) are considered. The asterisk (*) indicates those variables that were not considered significantly correlated to the same axis in Marramà and Kriwet (2017) (i.e., |loading| ≤ 0.5).
| PC | SV | % Variance | Cumulative % | Associated variables detected through geometric morphometrics | Associated variables detected in Marramà and Kriwet (2017) through traditional morphometrics |
| 1 | 0.64781 | 37.33% | 37.33% | BCW*, DS, HCW, LCH*, LCW*, PCH*, PCW*, RA*, RH*, RW* | DS, HCW, IMCE, MCL |
| 2 | 0.45347 | 18.29% | 55.62% | DS*, RA*, RH*, RW* | BCW, LCH, LCW, MCL |
| 3 | 0.38620 | 13.27% | 68.89% | ||
| 4 | 0.31342 | 8.74% | 77.63% | ||
| 5 | 0.29320 | 7.65% | 85.27% | ||
| 6 | 0.22793 | 4.62% | 89.90% | ||
| 7 | 0.17298 | 2.66% | 92.56% | ||
| 8 | 0.14481 | 1.87% | 94.42% | ||
| 9 | 0.12003 | 1.28% | 95.70% | ||
| 10 | 0.10939 | 1.06% | 96.77% | ||
| 11 | 0.09999 | 0.89% | 97.66% | ||
| 12 | 0.08568 | 0.65% | 98.31% | ||
| 13 | 0.07123 | 0.45% | 98.76% | ||
| 14 | 0.06663 | 0.39% | 99.16% | ||
| 15 | 0.05813 | 0.30% | 99.46% | ||
| 16 | 0.04545 | 0.18% | 99.64% | ||
| 17 | 0.04265 | 0.16% | 99.80% | ||
| 18 | 0.03261 | 0.09% | 99.90% | ||
| 19 | 0.02009 | 0.04% | 99.93% | ||
| 20 | 0.01641 | 0.02% | 99.96% | ||
| 21 | 0.01208 | 0.01% | 99.97% | ||
| 22 | 0.01110 | 0.01% | 99.98% | ||
| 23 | 0.00939 | 0.01% | 99.99% | ||
| 24 | 0.00784 | 0.01% | 100.00% | ||
| 25 | 0.00533 | 0.00% | 100.00% | ||
| 26 | 0.00460 | 0.00% | 100.00% |
TABLE 4. Results of the non-parametric PERMANOVA and ANOSIM tests for the comparison between Brachycarcharias and Lamna morphospaces.
| PERMANOVA | ||
| p-values | Brachycarcharias | Lamna |
| Brachycarcharias | 0.0001* | |
| Lamna | ||
| F-values | ||
| Brachycarcharias | 7.619 | |
| Lamna | ||
| ANOSIM | ||
| p-values | Brachycarcharias | Lamna |
| Brachycarcharias | 0.0001* | |
| Lamna | ||
| R-values | ||
| Brachycarcharias | 0.3497 | |
| Lamna |
TABLE 5. Principal component axes, singular values, percent variation, cumulative percentage and associated variables for the sample of Brachycarcharias and Carcharias. Only the first two axes (in bold) are considered. The asterisk (*) indicates those variables that were not considered significantly correlated to the same axis in Marramà and Kriwet (2017) (i.e., |loading| ≤ 0.5).
| PC | SV | % Variance | Cumulative % | Associated variables detected through geometric morphometrics |
Associated variables detected in Marramà and Kriwet (2017) through traditional morphometrics |
| 1 | 1.03990 | 73.11% | 73.11% | BCW, DS, HCW, LCH, LCW, PCH*, PCW, RA, RH*, RW | BCW, DS, HCW, IDCE, LCH, LCW, PCW, RA, RW |
| 2 | 0.35049 | 8.30% | 81.41% | DS*, RA*, RH*, RW* | BCW, LCH, LCW |
| 3 | 0.28140 | 5.35% | 86.76% | ||
| 4 | 0.24456 | 4.04% | 90.81% | ||
| 5 | 0.19215 | 2.50% | 93.30% | ||
| 6 | 0.15544 | 1.63% | 94.94% | ||
| 7 | 0.14789 | 1.48% | 96.42% | ||
| 8 | 0.10375 | 0.73% | 97.14% | ||
| 9 | 0.09766 | 0.64% | 97.79% | ||
| 10 | 0.09036 | 0.55% | 98.34% | ||
| 11 | 0.07910 | 0.42% | 98.76% | ||
| 12 | 0.06824 | 0.31% | 99.08% | ||
| 13 | 0.06346 | 0.27% | 99.35% | ||
| 14 | 0.05448 | 0.20% | 99.55% | ||
| 15 | 0.04376 | 0.13% | 99.68% | ||
| 16 | 0.04071 | 0.11% | 99.79% | ||
| 17 | 0.03572 | 0.09% | 99.88% | ||
| 18 | 0.02989 | 0.06% | 99.94% | ||
| 19 | 0.01863 | 0.02% | 99.96% | ||
| 20 | 0.01303 | 0.01% | 99.97% | ||
| 21 | 0.01201 | 0.01% | 99.98% | ||
| 22 | 0.00997 | 0.01% | 99.99% | ||
| 23 | 0.00767 | 0.00% | 99.99% | ||
| 24 | 0.00692 | 0.00% | 100.00% | ||
| 25 | 0.00503 | 0.00% | 100.00% | ||
| 26 | 0.00332 | 0.00% | 100.00% |
TABLE 6. Results of the non-parametric PERMANOVA and ANOSIM tests for the comparison between Brachycarcharias and Carcharias morphospaces.
| PERMANOVA | ||
| p-values | Brachycarcharias | Carcharias |
| Brachycarcharias | 0.0010* | |
| Carcharias | ||
| F-values | ||
| Brachycarcharias | 9.911 | |
| Carcharias | ||
| ANOSIM | ||
| p-values | Brachycarcharias | Carcharias |
| Brachycarcharias | 0.0059* | |
| Carcharias | ||
| R-values | ||
| Brachycarcharias | 0.1561 | |
| Carcharias |
TABLE 7. Principal component axes, singular values, percent variation, cumulative percentage and associated variables for the sample of Brachycarcharias and Carcharomodus. Only the first two axes (in bold) are considered. The asterisk (*) indicates those variables that were not considered significantly correlated to the same axis in Marramà and Kriwet (2017) (i.e., |loading| ≤ 0.5).
| PC | SV | % Variance | Cumulative % | Associated variables detected through geometric morphometrics |
Associated variables detected in Marramà and Kriwet (2017) through traditional morphometrics |
| 1 | 0.47240 | 48.38% | 48.38% | BCW*, DS, HCW*, LCH*, LCW*, PCH*, PCW*, RA*, RH*, RW* | DS, IMCE, MCL |
| 2 | 0.28952 | 18.17% | 66.56% | DS*, LCH, LCW, RA, RH*, RW* | HCW, LCH, LCW, RA |
| 3 | 0.26025 | 14.68% | 81.24% | ||
| 4 | 0.16835 | 6.14% | 87.39% | ||
| 5 | 0.15207 | 5.01% | 92.40% | ||
| 6 | 0.10016 | 2.18% | 94.58% | ||
| 7 | 0.08009 | 1.39% | 95.97% | ||
| 8 | 0.06775 | 1.00% | 96.96% | ||
| 9 | 0.06253 | 0.85% | 97.81% | ||
| 10 | 0.05654 | 0.69% | 98.50% | ||
| 11 | 0.04794 | 0.50% | 99.00% | ||
| 12 | 0.04062 | 0.36% | 99.36% | ||
| 13 | 0.03133 | 0.21% | 99.57% | ||
| 14 | 0.02642 | 0.15% | 99.72% | ||
| 15 | 0.02145 | 0.10% | 99.82% | ||
| 16 | 0.01764 | 0.07% | 99.89% | ||
| 17 | 0.01470 | 0.05% | 99.94% | ||
| 18 | 0.01285 | 0.04% | 99.97% | ||
| 19 | 0.00781 | 0.01% | 99.99% | ||
| 20 | 0.00623 | 0.01% | 99.99% | ||
| 21 | 0.00344 | 0.00% | 100.00% | ||
| 22 | 0.00301 | 0.00% | 100.00% | ||
| 23 | 0.00256 | 0.00% | 100.00% | ||
| 24 | 0.00081 | 0.00% | 100.00% | ||
| 25 | 0.00028 | 0.00% | 100.00% |
TABLE 8. Results of the non-parametric PERMANOVA and ANOSIM tests for the comparison between Brachycarcharias and Carcharomodus morphospaces.
| PERMANOVA | ||
| p-values | Brachycarcharias | Carcharomodus |
| Brachycarcharias | 0.0170* | |
| Carcharomodus | ||
| F-values | ||
| Brachycarcharias | 3.584 | |
| Carcharomodus | ||
| ANOSIM | ||
| p-values | Brachycarcharias | Carcharomodus |
| Brachycarcharias | 0.0176* | |
| Carcharomodus | ||
| R-values | ||
| Brachycarcharias | 0.2281 | |
| Carcharomodus |
TABLE 9. Relative contribution of each landmark point measured as sum of squares in the overall sample analysis.
| Landmark | Sum of squares |
| L2 | 0.13815 |
| L4 | 0.11717 |
| L6 | 0.08432 |
| L7 | 0.08378 |
| L3 | 0.07663 |
| S4 | 0.07339 |
| S5 | 0.06989 |
| L5 | 0.06782 |
| S1 | 0.06166 |
| S8 | 0.06071 |
| S6 | 0.04959 |
| S3 | 0.04803 |
| S7 | 0.03704 |
| S2 | 0.03151 |
| L1 | 0.00031 |
| Sum | 1.00 |
TABLE 10. Relative contribution of each landmark point measured as sum of squares in the pairwise comparison between Brachycarcharias and Lamna.
| Landmark | Sum of squares |
| L2 | 0.10848 |
| L7 | 0.09806 |
| L6 | 0.09308 |
| L4 | 0.09015 |
| S4 | 0.07894 |
| S5 | 0.07474 |
| S8 | 0.07394 |
| S1 | 0.07099 |
| L3 | 0.06272 |
| L5 | 0.05617 |
| S6 | 0.05526 |
| S3 | 0.05421 |
| S7 | 0.04505 |
| S2 | 0.03785 |
| L1 | 0.00036 |
| Sum | 1.00 |
TABLE 11. Relative contribution of each landmark point measured as sum of squares in the pairwise comparison between Brachycarcharias and Carcharias.
| Landmark | Sum of squares |
| L2 | 0.13886 |
| L4 | 0.12815 |
| S4 | 0.08313 |
| L6 | 0.08096 |
| S5 | 0.07996 |
| L7 | 0.07889 |
| L3 | 0.06229 |
| S1 | 0.06139 |
| L5 | 0.06082 |
| S8 | 0.05543 |
| S6 | 0.05326 |
| S3 | 0.05042 |
| S7 | 0.03542 |
| S2 | 0.03073 |
| L1 | 0.00029 |
| Sum | 1.00 |
TABLE 12. Relative contribution of each landmark point measured as sum of squares in the pairwise comparison between Brachycarcharias and Carcharomodus.
| Landmark | Sum of squares |
| S4 | 0.10653 |
| S5 | 0.10221 |
| S1 | 0.09080 |
| S3 | 0.08573 |
| S6 | 0.07896 |
| S2 | 0.07521 |
| L6 | 0.07518 |
| L2 | 0.07300 |
| L4 | 0.06290 |
| S8 | 0.05913 |
| L7 | 0.05603 |
| S7 | 0.05576 |
| L5 | 0.04008 |
| L3 | 0.03817 |
| L1 | 0.00030 |
| Sum | 1.00 |
