The Tail of a Mosasaur - A Window on the Tempo and Mode of Evolution in Aquatic Tetrapods

Explore the evolutionary journey of mosasaurs in this 57-minute Royal Tyrrell Museum Speaker Series lecture. Delve into the fascinating world of aquatic tetrapods as paleontologist Takuya Konishi examines the tail anatomy of Platecarpus tympaniticus. Learn about micro and macroevolution, rates of evolutionary change, and the significance of squamation in marine reptiles. Discover how the bent tail structure of mosasaurs challenges previous straight-tail reconstructions and gain insights into the feeding habits, internal organs, and reproductive strategies of these ancient marine predators. Compare mosasaur anatomy with modern monitor lizards and cetaceans, and understand how this research contributes to our understanding of evolutionary adaptations in aquatic environments during the Late Cretaceous period.

The Tail of a Mosasaur-A Window on the Tempo and Mode of Evolution in Aquatic Tetrapods
What's Evolution?
Microevolution
Macroevolution
Rates of Evolution
2009 GEOLOGIC TIME SCALE
What we see today...
existed in Mesozoic seas
Squamates
Squamation = Imbricate Scales
Mosasaurs—size matters
Mosasaurs Introduction
Food for thought...
Mosasaur (Ovo)viviparity
Late Cretaceous (ca. 100 Ma-) North America
Platecarpus tympaniticus (LACM 128319)
Features on Head
Cont'd (Eye)
Internal Organs and Gut Contents
Comparison with Monitor Lizard and Cetacean (Dolphin)
Tail Anatomy—It's Bent!
Previous Tail Reconstruction in Mosasaurs—Straight?
Tail of an Aigialosaur-Also Straight.
Some Numerical Results
Platecarpus Reconstructed
How did we reconstruct the crescent- shaped tail fin in Platecarpus?
The Tale of the Tail of Platecarpus
Mosasaurs were NOT an exception
Acknowledgments