Compare extinct and modern whales and dolphins

Erich Fitzgerald is a palaeontologist at Museum Victoria. He uses measurement to find out more about ancient and extinct animals. Watch the following videos, then you will be ready to take on the challenge that is detailed below.

Watch this video with a transcript

If you are ready to try your hand as a palaeontologist, take a look at this video where Erich talks about measuring skull ratios.

Watch this video with a transcript

The Challenge: Compare extinct and modern whales and dolphins

Your Challenge is to use the measurements of the animal skulls to explore the following questions?

  • How did the extinct whale, Janjucetus (pronounced jan-jah-see-tus), eat?
  • What do we think this extinct whale ate? What do think were its feeding habits?


The Common dolphin is known to eat small, fast moving fish. To help you investigate questions above, take a look at the images of the skulls (in the Related Resources document) of the Common dolphin, the ancient whale and other species linked below. Use the images to figure out the measurements needed to complete the table below including the ratios in the last column.

AnimalUpper jaw length (mouth/nose)Total skull lengthUpper jaw length: Total skull lengthDiet/feeding habits

Common dolphin

      Eats small, fast moving fish

Extinct whale Janjucetus

Other whale or dolphin species        

Does it work for other types of whales and dolphin alive today? Use the links below to view images of the skulls of other whales and dolphins and do some further research to explore what were the feeding habits of these animals.  What conclusions can you come to about the ratio of the upper jaw length compared to the total skull length and what they ate?

Links to Images


Questions and considerations:

  • Ratios – look at different ways of representing ratios so that they can be compared easily – eg could you convert the ratio into percentages?


Share your solutions with others. What does the maths tell us about what ancient and modern dolphins and whales ate and what their feeding habits were like?

We would love you to share your solutions with us. Email us a report on your findings. You may even send a video presentation or a link to it, explaining your discoveries and the maths you used in your investigations.

Comments (2)

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Jacinta, Andy, Jothi and Natasha 31 October, 2013 09:20
Can you please tell us the jawline measurements and skull measurements for a bottle nose dolphin and killer whale. Thank you! From Jacinta, Andy, Jothi and Natasha
Daniel 13 November, 2013 18:53
Hi Jacinta, Andy, Jothi and Natasha, thanks for your question. I'm assuming you are working on this challenge. If you click on the name of each of these animals in the text above, you will see photographs of the skulls of each animal that you can use to work out the relative measurements that you need. When investigating this challenge, keep in mind that you will be working with ratios, so do you need the 'actual real-life' measurements or could you use the photographs to give you an indication of these measurements?
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