Survival and extinction of sex-determining mechanisms in Cretaceous tetrapods

Recognizing the mechanisms that influence the survival/extinction rates of species as a result of environmental changes in the past may help to understand future trends in biodiversity loss by current global change. In this study we examined whether non-dinosaur tetrapods with genetic sex determination (ZZ-ZW and XX-XY) and temperature-dependent sex determination (TSD) led to differential survival at the Cretaceous/Palaeogene boundary event. Our results showed that 79% of the species with XY mechanism went extinct, while 13% and 23% of the species with TSD and ZW mechanisms went extinct, respectively. Our results suggest that sex-determining mechanisms might have played an important role in the survival of species. Other possible variables should also be considered to determine the role of plasticity of TSD and GSD species in mass extinction processes.