June 21, 2021
  • 7:30 am Committee reaffirms mandatory denominational health plan
  • 7:27 am Rapidísimas
  • 7:23 am Video: Presiding Bishop Curry on World Refugee Day
  • 7:22 am Episcopalians approach Donald Trump’s inauguration with prayer
  • 7:20 am Episcopal racial reconciliation event draws large crowd in Lexington, Virginia

first_imgMass accumulations of belemnite rostra (‘belemnite battlefields’) are common in Mesozoic sediments, and accumulations of belemnoids are also known from older rocks. Many Recent teuthid species suffer mortality immediately after spawning, and some authors have suggested that belemnite accumulations record a similar phenomenon. Conversely, it is clear that many belemnite battlefields actually formed in an environment of net sediment loss, with current alignment and winnowing. A proposed model for the production of belemnite battlefields involves five possible pathways: post-spawning mortality, catastrophic mass mortality, predation concentration, stratigraphical condensation, and resedimentation. Although accumulations that have not been reworked are rare, it is possible to recognise the generating agents of belemnite accumulations through their intrinsic features. A genetic classification of belemnite battlefields, based on the identified pathways, is tested through field examples in Britain and Antarctica, as well as through published exampleslast_img read more