So I was pleased to see that a free, online, university run course called 'Ancient Marine Reptiles' was available through online course specialists Coursera.
You can start the course at any time and progress through it at your own pace. It is divided into 'weeks', of which there are 4: Introduction to Marine Reptiles; Ichthyopterygians; Sauropterygians; and Mosasauroids. It is video-based and supported by copious course notes and numerous further reading references that you can chase down if you want. It also has some supporting interactive tools such as a phylogenetic tree, which you can use to explore the origins of a large range of species. Each 'week' takes up to 4 hours to complete.
The emphasis of the course is on adaptations to marine life because all 3 of these groups (Which we think of as ichthyosaurs, pliosaurs & plesiosaurs, and mosasaurs), were originally land-based animals that returned to the sea, in much the same way as whales did.
Weeks 2 to 4 go into how each group solved the 'aquatic problem', their evolution and their global distribution through time.
Each week is peppered with interactive questions (to make sure you're listening) and followed by a short quiz (Nothing too taxing). At the end of the course you get a grade based on these quizzes.
I found the course interesting and very informative. The lecturer, Scott Persons, was enthusiastic without over doing it and there were plenty of pictures to break up the lectures. My main gripe was that there weren't enough fossils on show to illustrate his points. Maybe they thought drawings would be clearer?
Rating: 8/10
Course available here from University of Alberta.
They also do 2 other courses: Theropod Dinosaurs; and Early Vertebrate Evolution.