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What is the context of this research?

Whales, in their transition from terrestrial to

fully aquatic lifestyles, have modified their mammalian form to support living and feeding under water. Toothed whales originated ~34 million years ago, and are thought to have quickly (across a span of ~10 million years) developed the ability to echolocate.



Semirostrum ceruttii, an extinct porpoise that lived 3-5 million years ago, has a particularly unusual jaw shape, never seen before in a mammal. It shares characteristics with vertebrates from distinctly different lineages (i.e., birds and fish).



The function of the jaw, and whether its specialized shape reduced the importance of echolocation in this animal, has yet to be fully investigated. Hypotheses can be tested using a combination of quantitative anatomical methods based on CT scans.

What is the significance of this project?

Testing hypotheses about the relationship between form and function is integral to the study of evolution. Extinct species can be brought to ”life” through reconstructions of the head using modern methods in functional morphology.



Simulating possible functions of unusual morphologies, such as that observed in Semirostrum ceruttii, can provide a window into past exploration of morphospace and ecological possibilities that are not observed in modern mammals.



Further, CT data represent an important resource in the earth and natural sciences, allowing three-dimensional, non-destructive examination of internal features, tests of bending and load stresses on bones. They are permanent digital records available to future researchers, museums, and the general public.

What are the goals of the project?

I will test the hypothesis that unique skull and jaw shape in Semirostrum ceruttii were driven by feeding habits. Particularly, I will assess whether it was suited to probing in the benthos, and simulate how it brought prey into its mouth.

