Thecodont, diphyodont and heterodont teeth are characteristic of
The correct option is C Mammals/man Thecodont dentition is a morphological arrangement in which the base of the tooth is completely enclosed in a deep socket of bone, as seen in crocodilians, dinosaurs and mammals.
Diphyodont is a type of dentition characterised by two sets of teeth. Most mammals are diphyodonts, as to chew their food they need a strong, durable and complete set of teeth.
Heterodont is an animal which possesses more than a single tooth morphology. In vertebrates, heterodont pertains to animals where teeth are differentiated into different forms. For example, human teeth are heterodont.