Supplementary figure 1. The developing soft palate and nasal plugs in all non-invasively imaged rorquals. from Heterochronic maturation of anatomical plugs for protecting the airway in rorqual whales (Balaenopteridae)

(a) Sagittal (top row), coronal (middle row) and transversal (bottom row) magnetic resonance imaging slices though the nasopharyngeal cavity in early and mid-fetal blue whales (Balaenoptera musculus, B. mus), early fetal fin whale (Balaenoptera physalus, B. phy), mid-fetal humpback whale (Megaptera novaeangliae, M. nov), and prenatal minke whale (Balaenoptera acutorostrata, B. acu). (b) Sagittal (top row), coronal (middle row) and transversal (bottom row) magnetic resonance imaging slices though the nasal plugs in same specimens as in (a). Scale bars represent 10 mm on all images. Yellow and blue dotted lines on sagittal images show slice position of the coronal and transversal slices, respectively.