Materials in nature often have an intricate structure that can be employed as bio-templates to develop inorganic materials with hierarchical structural features. In the present study, biomorphic alumina ceramics have been prepared utilizing eggshell membrane (ESM) as a bio-template. Different phases of alumina are evolved depending on the calcination temperature. The interwoven fibrous structure retained from the ESM template is composed of alumina nanocrystallites that evolved through a bottom-up assembly process directed by the ESM bio-macromolecules. The in situ transmission electron microscopy studies indicated the oriented attachment growth, a non-classical crystal growth mechanism. This can be considered as a plausible mechanism for the formation of α-Al2O3 single crystal platelets. The nanocrystallites formed at comparatively lower calcination temperatures are the primary building units for the platelets. The amino acids of the ESMs acted as a capping agent, which controlled the crystal growth process through molecular-level interactions. The insights from this finding on the formation of α-Al2O3 platelets can pave the way for developing tailored ceramic materials utilizing bio-templates. It has also been found that the ESM is an intrinsic source of carbon and sulfur during the development of C-ZnO and C-ZnS.