Mammals Inherit the Earth

This lecture examines the Cretaceous–Paleogene mass extinction and its effects on mammalian diversity, body size, ecology, and evolutionary radiation. It draws on North American fossil records, stratigraphy, anatomy, and dental-complexity analysis to evaluate extinction causes and survivor patterns.

Syllabus

Intro
The Ups and Downs of the last 600 m.y.
Cretaceous-Paleogene (K-Pg) mass extinction
K-Pg extraterrestrial impact
K-Pg Deccan volcanism Mahabaleshwar, India
K-Pg extinction hypotheses
Cretaceous terrestrial vertebrate localities
Paleocene terrestrial vertebrate localities
The Hell Creek Study System
Coastal lowland setting
K-Pg boundary layer (2 cm thick)
Temporal framework
Dinosaur icons
Prospect & surface collect
Place fossil locs in stratigraphic context
Record geology & collect fossiliferous sediment
Screen-wash fossiliferous sediment
New fossils show some ecological diversification
K-Pg: A watershed event for mammals taxonomic richness
K-Pg mammals of northeastern MT
Cranium-NDGS 431
Mammalian fossil sampling
The anatomy of the K-Pg mass extinction
Endangered species 3,600 Black rhinos
Ecological disturbance
or limping to the finish line ✓ Declining faunal evenness and relative abundances of metatherians implies ecological instability during the last 500 k.y of the Cretaceous
Who were the winners & losers?
Methodological Premise
Homology-free dental complexity
Modern Study Carnivorans & Rodents
Dental complexity across the K-Pg