Atmospheric carbon dioxide/oxygen imbalance in the late Cretaceous, hatching of eggs and the extinction of biota
Date
1978
Authors
Oelofsen, B. W.
Journal Title
Journal ISSN
Volume Title
Publisher
Bernard Price Institute for Palaeontological Research
Abstract
A new theory explains why dinosaurs, pterosaurs and large avian species like Hesperornis
became extinct at the end of the Cretaceous while mammals, smaller Cretaceous birds, crocodiles,
chelonians and saurians survived .
An atmospheric carbon dioxide/oxygen imbalance at the end of the Cretaceous caused by
kimberlite volcanism, basalt flows and a reduction in oxygen production by marine phytoplankton
is proposed.
The unfavourable area to volume ratio of large eggs for diffusion of respiratory gases compared
to that of small eggs resulted in the asphyxiation of the embryos of large endothermic egg
laying groups. Endothermic species, e.g. dinosaurs that covered their eggs with soil, restricted
the free circulation of air and would have been first to become extinct. Smaller ectothermic species,
e.g. crocodiles, chelonians and saurians with lower embryonic respiratory requirements and
endothermic species like the birds that did not cover their eggs, survived.
Description
Main article
Keywords
Dinosaur; Cretaceous; Eggs; Extinction; Atmospheric
Citation
None