Supplementary video 1. Respiratory fly through of fetal minke whale. from Heterochronic maturation of anatomical plugs for protecting the airway in rorqual whales (Balaenopteridae)

Annotated upper respiratory fly through video of volume reconstructed early fetal fin whale (Balaenoptera physalus), 3.9% birth length, using high field magnetic resonance imaging. The camera enters the whale through the oral cavity where the hard and soft palate are visible. Then it continues underneath the soft palate to the nasopharynx where the epiglottis is visible. From there the camera continues to the nasal passages following the left nasal passage where the left nasal plug can be observed and finally exiting the respiratory tract via the blowhole. The video can be played at decreased speed to better appreciate anatomical features.