My main study organisms from the Cretaceous marine realm are mosasaurs, marine lizards that came to dominate the oceans over the last 30 million years of the Age of Dinosaurs. Mosasaurs ranged in size from a couple of meters (~6 ft) up to 17 meters (~56 ft) in length, with some rivaling the size of the largest toothed whales in our modern oceans. Based on tooth shape and preserved gut contents, we know that some mosasaurs ate anything they could get their mouths around, whereas some were fish specialists (piscivores), and others were even clam specialists (durophagous). They are a great study system for understanding the evolution of marine ecosystems because they have an abundant fossil record for a group of large vertebrates, were diverse throughout their geologic and geographic range, and filled numerous niches (ecological roles) within the ecosystem.
My long-term goal is to better understand the abiotic and biotic drivers of mosasaur evolution. I'm especially interested in how changes in climate and oceanography may have acted as selective pressures to produce an increase in diversity in one particular lineage of mosasaurs.
Publications:
Lively, J.R. submitted. Redescription and phylogenetic assessment of ‘Prognathodon’ stadtmani: implications for Globidensini monophyly and character homology in Mosasaurinae. Journal of Vertebrate Paleontology.
Lively, J.R. 2018. Taxonomy and historical inertia: Clidastes (Squamata: Mosasauridae) as a case study of problematic paleobiological taxonomy. A global perspective on Mesozoic marine reptiles: Proceedings of the 5th Triennial Mosasaur Meeting 2016. Alcheringa 42(4):516-527. [published online January, 2019]
Ongoing projects include:
My long-term goal is to better understand the abiotic and biotic drivers of mosasaur evolution. I'm especially interested in how changes in climate and oceanography may have acted as selective pressures to produce an increase in diversity in one particular lineage of mosasaurs.
Publications:
Lively, J.R. submitted. Redescription and phylogenetic assessment of ‘Prognathodon’ stadtmani: implications for Globidensini monophyly and character homology in Mosasaurinae. Journal of Vertebrate Paleontology.
Lively, J.R. 2018. Taxonomy and historical inertia: Clidastes (Squamata: Mosasauridae) as a case study of problematic paleobiological taxonomy. A global perspective on Mesozoic marine reptiles: Proceedings of the 5th Triennial Mosasaur Meeting 2016. Alcheringa 42(4):516-527. [published online January, 2019]
Ongoing projects include:
- Changes in anatomical diversity (disparity) in mosasaurs through their evolutionary history.
- Evolution, variation, and a taxonomic revision of early-diverging mosasaurines.
- A new genus and species of mosasaur from Texas elucidates the origins of 'Globidensini.'