@article{article_690444, title={(German) KANN DER FAUNENWANDEL VOM MESOZOIKUM ZUM KÄNOZOIKUM DURCH EINE KATASTROPHE ERKLÄRT WERDEN?}, journal={Türkiye Jeoloji Bülteni}, volume={6}, pages={69–77}, year={1958}, author={Turnovsky, Kurt}, keywords={FAUNENWANDEL,MESOZOIKUM,KÄNOZOIKUM}, abstract={<div style="text-align:justify;"> <span style="font-size:12px;">From time to time somebody forwards the opinion that between the Mesozoic and the Kainozoic some catastrophic event must have happened, to account for the difference in the fauna, especially the extinction of the Dinosaurs. This is considered to be wholly unnecessary. </span> </div> <div style="text-align:justify;"> <span style="font-size:12px;">1. The faunal change is not as sudden as it seems on superficial observation. Some mesozoic forms disappear already before the conventional boundary between the Cretacous and the Tertiary, others survive it (v. Ammonoidea and Belemnoidea). Modern types (Placentalia, Octopoda) make their appearance already in the Upper Cretaceous. Thus the appearance of new, the extinction of old forms is a drawn-out process, lasting from about Turonia n up to the Eocene, with probably a peak at the top of the Maestrichtian. </span> </div> <div style="text-align:justify;"> <span style="font-size:12px;">2. Extinction mainly concerns forms of high specialization which are at the end of an evolutionary cycle. Such forms are susceptible to even small changes in external conditions, which do not touch more robust forms. Small initial changes may lead to a cumulative effect. </span> </div> <div style="text-align:justify;"> <span style="font-size:12px;">The faunal change between Mesozoic and Kainozoic is no more catastrophic than any other in the history of life. </span> </div>}, number={2}, publisher={TMMOB Jeoloji Mühendisleri Odası}