Class Central is learner-supported. When you buy through links on our site, we may earn an affiliate commission.

University of Alberta

Paleontology: Ancient Marine Reptiles

University of Alberta via Coursera


Paleontology: Ancient Marine Reptiles is a four-lesson course teaching a comprehensive overview of the evolutionary changes that occur when air-breathing terrestrial animals return to water. This course examines the diversity, adaptations, convergence, and phylogenetic relationships of extinct marine reptiles. Students will explore three major groups of marine reptiles: ichthyosaurs, plesiosaurs, and mosasaurs. Watch a preview of the course here:


  • Introduction to Marine Reptiles
    • Welcome to the first lesson of Palaeontology: Ancient Marine Reptiles. In this lesson we will explore the main theme of the course: the aquatic problem. In other words, what happens when a terrestrial animal returns to the water permanently? How do air-breathing, land-lubbing creatures once again adapt to life in the sea? Life in water is very different than life on land. Water is much denser than air, which affects all aspects of an animal's life including movement, sight, and hearing. In addition, animals that return to the water cannot breathe water, and so must return to the surface for air. Water also conducts heat much better than air, making staying warm and active a challenge. Despite all these obstacles, many land animals have returned to the water throughout the course of evolutionary history. In fact, many examples of them are living today including whales, seals, crocodiles, sea turtles and penguins. Each of these animals had ancestors that returned to the water. The process of overcoming the challenges associated with this transition is what we refer to as the aquatic problem. This lesson will explore many different types of adaptations that modern and extinct animals have evolved to meet these challenges. You will be introduced to some extinct groups of reptiles you have probably never heard of, and will gain a new appreciation for how well suited modern marine animals are to their environment. Just a quick note before you get started: 'Palaios' is the Greek word for 'ancient', so palaeontology or paleontology is the study of ancient life. Both spellings are correct, with palaeontology used in Britain, and paleontology more common in the US.
  • Ichthyopterygians
    • Welcome back! We hope that you enjoyed the first lesson of the Ancient Marine Reptiles mini MOOC. In lesson one, we discussed a variety of modern and extinct groups of aquatic amniotes. Some of these groups would have been familiar to you, and some you had probably never heard of before. We also explored some of the many differences between living in water and living on land, and we gave examples of how some amniote groups have overcome these challenging differences. As you may have already seen, some of the solutions to the different aspects of the aquatic problem were solved in the same way by unrelated groups- a phenomenon called convergence.

      The next three lessons will build on your understanding of the aquatic problem as we investigate it more detail in three extinct groups of marine reptiles: the ichthyopterygians, sauropterygians, and mosasauroids. Each lesson will follow the same general outline. First, we will introduce you to the group and some of its diversity. The second part of each lesson will focus on how that group adapted to solve the aquatic problem, and how this resulted in specializations for feeding, locomotion and reproduction. Finally we will give you an overview of the evolutionary history of the group through time and space, as well as presenting some important fossils and localities from Canada and around the world.

      In lesson two, we will study the first of the three major groups of extinct marine amniotes: the ichthyopterygians. The ichthyopterygians were highly specialized animals. Most of the later members looked something like a dolphin or a tuna, a great example of convergent evolution. These reptiles were probably among the fastest aquatic creatures that ever lived. They were found all over the world, from the early Triassic to the mid-Cretaceous, a span of 150 million years.

      By the end of this lesson, you should be familiar with the history and diversity of this group, and be able to appreciate some of their impressive specializations to solve the aquatic problem.
  • Sauropterygians
    • Welcome back! We hope you enjoyed the lesson on ichthyopterygians, the first of three in depth explorations of an extinct marine reptile group that we will cover. In this lesson you learned that ichthyosaurs are among the most specialized reptiles that ever lived. They had many adaptations to solving the aquatic problem including large eyes for seeing in deep water, powerful tails to power their thunniform swimming, and two sets of flippers for stability and steering. We also discussed the hypothesis that ichthyosaurs may have overcome the problem of being cold-blooded reptiles living in water by evolving some endothermic capabilities. Even though ichthyopterygians were well adapted for a life in the water, this lineage still went extinct long before the End-Cretaceous Mass Extinction for unknown reasons.

      The lesson you are about to start will follow a similar format to lesson 2, but instead of ichthyopterygians, we will be investigating a second major marine reptile lineage: the sauropterygians. These animals shared the seas with the ichthyosaurs for much of their 180 million year existence. You may already know some of the members of this group such as the long-necked elasmosaurs and the massive-jawed pliosaurs such as Liopleurodon. In this lesson we will expand your knowledge of these animals by introducing you to their lizard-like ancestors and a wider variety of the derived members. We will present you with one of the biggest unsolved mysteries surrounding marine reptiles: how did plesiosaurs use their four massive, wing-like flippers to swim? We will also look at how they ate and reproduced, and we will finish by taking you on a worldwide tour of plesiosaur diversity through time.

      We hope you enjoy learning about this group of reptiles, who had adaptations so unique that they have never been seen in any other lineage of marine tetrapods.
  • Mosasauroids
    • Welcome to the final lesson in Palaeontology: Ancient Marine Reptiles. The lesson you just finished gave you an in depth look at one of the most morphologically disparate groups of marine tetrapods to ever live. There were the turtle-shaped placodonts with crushing teeth; the extraordinarily long-neck elasmosaurs; and the pliosaurs with jaws massive enough to take on nearly any prey. Even though sauropterygians evolved many different body plans, they all shared certain adaptations for solving the aquatic problem such as live birth and appendicular locomotion.
      In contrast, the final group we will investigate showed convergence on one morphotype. The mosasaurs, though diverse, were all fairly long reptiles, with large jaws, four flippers and a long, lobed tail. You may recognise one of them from Jurassic World, where an enormous genetically-engineered Mosasaurus leaped out of the water to eat a shark.

      This last lesson will once again start by examining the diversity of the group, from their terrestrial origins to last days of the Cretaceous when they ruled as apex predators. We will investigate the specific adaptations of the group to the aquatic problem, and finish with an overview of the history of mosasaurs throughout time and space.

      Please enjoy the last lesson of Palaeontology: Ancient Marine Reptiles. It is an appropriate way to finish this course since the mosasaurs were among the largest and most powerful marine predators to ever live, and were the last major marine reptile group to evolve during the Mesozoic.

Taught by

Michael Caldwell and Halle P. Street


4.9 rating, based on 32 Class Central reviews

4.9 rating at Coursera based on 1211 ratings

Start your review of Paleontology: Ancient Marine Reptiles

  • This course was really interesting and covered the three main types of marine reptiles. I liked how the readings went along with the videos so it works for different styles of learning.
  • Marine reptiles are often "lumped with the dinosaurs" and not much is spent on them. This was very helpful is having some more information about them.
  • Profile image for M Anderson
    M Anderson
    This is the third MOOC I have done from the University of Alberta and I feel like a crazed deadhead junkie waiting for the next course to drop! I have absolutely loved this course, I learned several new bone structures and adaptations that I have…
  • Anonymous
    Another great palaeontology course, have also done Dino 101 and Theropod Dinosaurs and the Origin of Birds. Very well presented courses, I really hope the University of Alberta bring out some more! It was interesting to learn that the Cretaceous period can be broken down into more sub groups. Love these courses!
  • Anonymous
    Was good fun and I learned a lot of nice facts I can take with me. Wish there would be a full bachelor program available online.
  • Bonnie Ellen Benson
    I would love to pay for this course for the joy of learning----but it is impossible to log on, links do not perform.
  • Anonymous
    Excellent course. Highly recommend to all geology and marine enthusiasts. Amazing teachers and representations.
  • Anonymous
    This is my third Coursera course with the University of Alberta (Bugs 101, Dinosaurs 101 & now Ancient Marine Reptiles} so, obviously, I am a fan. Speaking specifically about the Ancient Marine Reptiles course: The reading assignment covers the sa…
  • Anonymous
    apart from this the experience was excellent, and i want to thank the instructor who made my journey through this course very interesting!Best course, very useful for increase in my knowledge in paleontology and scientific thinking. It is helpful for developing the learning skills. It was very helpful for my career, as I want to become a paleontologist. It increased my knowledge in archeological thinking which is important as you have a fossil or bone and you have to give hypothesis about eating habits, morphology, evolution of that fossil or bone which is very difficult to predict. This course thought me thinking about organisms and there relation with environment and other organisms
  • Anonymous
    this was an amazing class! I took it as a rising junior to get a bit more knowledge and substance in my college apps, but it was so intriguing i ended up taking the other paleontology courses University of Alberta had to offer!
  • I have only words of praise for University of Alberta courses. The artistic level is amazing, the notes are detailed and wonderful - instead of just plain transcripts you get a small encyclopaedia! The lectures are fascinating, and you have a chance to see real-life fossils too. There are lots of interactive exercises, which are useful in learning, and a glossary too. All in all, all paleontological courses of UA are simply amazing, and certainly in the top 5 courses I have taken, and certainly the best paleontological courses.
  • Anonymous
    Great introductive course to ancient marine reptiles. I found it interesting and useful for me. The exercises in each video quite helpful to learn how to analyze the things.
  • Very well structured and easy to understand. I enjoy the videos and the drag and drop excersises. It's the first day and I can't stop!
  • Bill Heim
    More advanced than I thought it would be, which is a good thing as I was not looking for an entry level course. If you are at a beginner level, you might want to start with a more introductory class. The instructor was engaging, the quizzes followed the material well.
  • Anonymous
    I thoroughly enjoyed this course. I learned the basic information on the subject matter and it will make going to a Natural History Museum much more enjoyable. I liked the interactive exercises and the time-line diagrams helped me understand the p…
  • Hailey Meinen
    A lot of good information, but the presentation was a bit slow and not engaging. Could not access the linked material.
  • Anonymous
    Brilliant loads of stuff to learn , must admit didn’t know a great deal to start with but soon rectified that videos were great as were the written notes ( think next time I will read them before watching the vids ) two down two to go .....I’m loving it ...
  • Anonymous
    This course is very well presented, informative and interesting. I really enjoyed completing it and have learned heaps. Thank you to everyone involved in producing and presenting this course. Julie
  • Anonymous
    I absolutely loved this course! Granted, I'm very interested in Dinosaurs and their evolutionary history, but diving deeper into the marine reptiles was extremely fascinating. My professor was easy to follow and kept me engaged. The quizzes were meaningful and relevant, and I especially enjoy the format - read first, then watch the videos. This helps me because I might read through the course notes and find myself questioning a few things or not feeling like I've "completely got it", but then I watch the videos and it seems to all fall into place. Thanks for being awesome!
  • Anonymous
    I came into this knowing nothing, literally 0 about paleontology. At first I felt overwhelmed with all the terms and was lost on the time periods, however you are provided with an alphabetized, 17 page, glossary. This was very good news for me! I quickly overcame the jargon problem. Once I was more or less on the same page with the prof I came to find that I was retaining and able to utilize the information through out the course. I had lots of fun and am proud to say I know more than nothing about paleontology !

Never Stop Learning.

Get personalized course recommendations, track subjects and courses with reminders, and more.

Someone learning on their laptop while sitting on the floor.