Photographs of the holotype braincase (NHMUK PV R6775) of I. amberina in A: anterior, B: posterior; C: right lateral; D: left lateral; E: ventral; F: dorsal views. Abbreviations: atr, anterior tympanic recess; boc, basioccipital crest; bpr, basipterygoid recess; bsr, basisphenoid recess; bt, basal tubera; btw, basituberal web; CN, cranial nerves V, VII; cp, cultriform process; cvl, crista ventrolateralis of basisphenoid; fm, foramen magnum; oc, occipital condyle; ova, fenestra ovalis; pcr, paracondylar recess; pit, depression of the pituitary gland within the pituitary fossa; pp, paraoccipital process; prp, preotic pendant; psncr, parasagittal nuchal crest recess; scr, sub-condylar recess; snc, parasagittal nuchal crest; sok, supraoccipital knob; sta, sella turcica. Scale bar equals 50 mm.