Figure 1.
Geological and locality map for Seymour Island, north-eastern Antarctic Peninsula.
Roman numerals within the La Meseta Formation indicate Telms 1–7; Telm 4 is a very thin unit that can be traced intermittently along the boundary between Telms 3 and 5. KPB = Cretaceous/Paleogene boundary. Further details on stratigraphic nomenclature are contained in the text and S1 Appendix. Based on Montes et al [117], with modifications. Cross Valley lies between López de Bertodano Bay and Penguin Bay.
Figure 2.
The fossil record of 38 modern Southern Ocean molluscan genera.
Solid lines and dots depict actual fossil occurrences and ranges of 38 molluscan genera (1–26 = gastropods, 27–38 = bivalves). Full details as to how the occurrences and ranges were established within the stratigraphic framework are contained within the text and S2 Appendix. Klb 9 represents the topmost Maastrichtian stratigraphic unit of the LBF, KPB = Cretaceous/Paleogene boundary, and (10) is Kplb 10, the recovery interval and topmost informal stratigraphic unit of the LBF. T1–7 = Telms 1–7 of the LMF; ages (in Ma) are approximate and taken from Montes et al. [117] for the SF, CVF and topmost LMF (Telms 6–7). Further details on the age of the La Meseta Formation are given in S1 Appendix. Gastropods arranged in taxonomic order according to Bouchet & Rocroi [118]; bivalves according to Bouchet & Rocroi [119] and Taylor et al. [120]. 1.Calliotropis; 2. Collonia; 3. Euspira?; 4. Amauropsis?; 5. Falsilunatia; 6. Sinuber; 7. Perissodonta; 8. Probuccinum?; 9. cf. Germonea; 10. Prosipho; 11. Pareuthria; 12. Chlanidota; 13. Trophon; 14. Fulgurofusus; 15. Volutomitra?; 16. Miomelon?; 17. Tractolira; 18. Aforia?; 19. Spirotropis?; 20. Typhlomangelia; 21. Epitonium; 22. Acirsa; 23. Acteon; 24. Neoacteonina; 25. Tornatellaea; 26. Kaitoa; 27. Leionucula; 28. Yoldia (Aequiyoldia); 29. Limopsis; 30. Limatula; 31. Cyclocardia; 32. Parathyasira; 33. Conchocele; 34. Mysella; 35. Gaimardia; 36. Cyamiomactra; 37. Hiatella; 38. Thracia.
Table 1.
Numbers of gastropods and bivalves in the three stratigraphic intervals investigated.
Figure 3.
The stratigraphical radiation of the Neogastropoda in Antarctica.
Solid lines and dots depict actual fossil occurrences and ranges of 80 neogastropod species. Full details as to how the occurrences and ranges were established within the stratigraphic framework are contained within the text and S2 Appendix. Klb 9 represents the topmost Maastrichtian stratigraphic unit of the LBF, KPB = Cretaceous/Paleogene boundary, and (10) is Kplb 10, the recovery interval and topmost informal stratigraphic unit of the LBF. T1–7 = Telms 1–7 of the LMF; ages (in Ma) are approximate and taken from Montes et al. [117] for the SF, CVF and topmost LMF. Further details on the age of the La Meseta Formation are given in S1 Appendix. Gastropods arranged in taxonomic order according to Bouchet & Rocroi [118]. 1.Heteroterma sp. 2; 2. Heteroterma sp.; 3. Antarctissitys austrodema; 4. Pyropsis sp.; 5. Taioma charcotiana; 6. Taioma sobrali; 7. Taioma bicarinata; 8. Taioma? antarctocarinata; 9. “Cassidaria” mirabilis; 10. Neogastropod, n. gen. B; 11. Austrosphaera bulloides; 12. n. gen. woolfei; 13. “Colus” delrioae; 14. Probuccinum? palaiocostatum; 15. cf. Germonea n. sp.; 16.?Pseudotylostoma pyrinota; 17. n. gen.? polaris; 18. “Penion” n. sp. A; 19. “Penion” n. sp. B; 20. Penion australocapax; 21. Prosipho stilwelli; 22. Prosipho lawsi; 23. Prosipho delli; 24. Prosipho polaris; 25. Prosipho antarctocosta; 26. Prosipho n. sp. 1; 27. Prosipho lamesetaensis; 28. Pareuthria hookeri; 29. Pareuthria n. sp. 1; 30. Chlanidota antarctica; 31. Chlanidota tuberosa; 32. Chlanidota antarctohimaleos; 33. Chlanidota?antarctohimaleos; 34. Chlanidota n. sp. 1; 35. Austroficopsis seymourensis; 36. Austroficopsis wimani; 37. Austroficopsis australis; 38. Austroficopsis austrinus; 39. Austroficopsis meridionalis; 40. n. gen. verrucosa; 41. Neogastropod, n. gen. A; 42. Cryptorhytis philippiana; 43. Microfulgur binodosa; 44. Paleopsephaea? nodoprosta; 45. Fusinus? doylei; 46. Microfulgur byrdi; 47. Fusinus? eonodatus; 48. Fusinus? suraknisos; 49. Fusinus? graciloaustralis; 50. Trophon radwini; 51. Eupleura suroabdita; 52. Turbinellidae indet.; 53. Fulgurofusus brecheri; 54. Miomelon? sp.; 55. Adelomelon fordycei; 56.?Adelomelon suropsilos; 57. Odontocymbiola amundseni; 58. Miomelon antarctica; 59. Tractolira n. sp.; 60. Volutomitra? antarctmella; 61. Volutomitra? cernohorskyi; 62. Volutomitra? iredalei; 63. Marshallaria? sp.; 64.?Cosmasyrinx (Tholitoma) antarctigera; 65. Zemacies finlayi; 66. Aforia canalomos; 67. Marshallaria? oliveroi; 68. Austrotoma n. sp.; 69. Austrotoma? ventricosa; 70. Austrosullivania lata; 71. Austrosullivania striata; 72. Gemmula askinae; 73. Spirotropis? n. sp.; 74. Typhlomangelia? n. sp.; 75. Agladrillia? n. sp.; 76. Makiyamaia? n. sp.; 77.? Splendrillia antarctoliqua; 78.? Cochlespira brychiosinus; 79. Pristimercia australis; 80. Coptostomella? notopolaris. Species 1–10 unassigned to superfamily; 11–49, Buccinoidea; 50–62, Muricoidea; 63–78, Conoidea; 79–80, Cancellarioidea.