Related Experiment Video
Updated: Aug 9, 2026

Who is Who? Non-invasive Methods to Individually Sex and Mark Altricial Chicks
Published on: May 24, 2014
Mass survival of birds across the Cretaceous-Tertiary boundary: molecular evidence
1School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand. alan.cooper@bioanth.ox.ac.uk
Abstract:
The extent of terrestrial vertebrate extinctions at the end of the Cretaceous is poorly understood, and estimates have ranged from a mass extinction to limited extinctions of specific groups. Molecular and paleontological data demonstrate that modern bird orders started diverging in the Early Cretaceous; at least 22 avian lineages of modern birds cross the Cretaceous-Tertiary boundary. Data for several other terrestrial vertebrate groups indicate a similar pattern of survival and, taken together, favor incremental changes during a Cretaceous diversification of birds and mammals rather than an explosive radiation in the Early Tertiary.
Related Concept Videos
Speciation Rates
Conservation of Declining Populations
Genetics of Speciation
The Evidence for Evolution
The Fossil Record
Convergent Evolution

