Atmospheric carbon dioxide/oxygen imbalance in the late Cretaceous, hatching of eggs and the extinction of biota

Main articleA 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.Non

A new record for Ptenopus (Reptilia: Gekkonidae) from calitzdorp

No Abstrac

Renal and salt gland function in the Jackass penguin (Speniscus [i.e. Spheniscus] demersus Linn.) with special reference to the renal portal system

Thesis (M. Sc.) -- University of Stellenbosch, 1973.Full text to be digitised and attached to bibliographic record

An anatomical and systematic study of the family Mesosauridae (reptilia : proganosauria) with special reference to its associated fauna and palaeoecological environment in the Whitehill Sea

Thesis (Ph.D.) -- University of Stellenbosch, [1981?].ENGLISH ABSTRACT: The anatomy and taxonomy of the southern African fossil reptile Mesosaurus from the Whitehill Shale has shown that the Formation is a chronostratigraphic unit. It is postulated that the almost identical Whitehill and Iraty Formations were deposited in shallow contemporaneous embayments of a central sea arm that occupied a position between the two continents. The water body was stratefied with anoxic, toxic, bottom brines that prevented the establishment of a benthonic fauna. A Study of the newly collected fossil material led to a new interpretation of the cranial morphology of Mesosaurus and it was found to be anapsid and closely allied to Limnoscelis. If M.tenuidens is to be regarded as typical for the Mesosauridae, all the members of the order Proganosauria will have to be transferred to the order Cotylosauria. M. tenuids was found to differ from M.brasiliensis and is the only species of Mesosaurus in the southern African Permo-Carboniferous Whitehill Formation. Along with it two more forms, noteosaurus africanus Broom and a yet unidentified species, identical with or closely allied to Stereosternum tumidum occur

Using history dependence to design a dynamic tradeable quota system under market imperfections

Transferable quota, Market imperfection, History dependence, Q22, Q28, D42,