Evolutionary Trends in Reptilian Hypothalamus

The hypothalami of amniote vertebrates have been shown to contain cluster-like subunits of parvocellular and magnocellular nuclei. Since mammals and birds have descended from reptiles, the reptilian hypothalamus offers a key for tracing the evolutionary development. Therefore, the patterns of hypothalamic neuronal organization in a lizard (Calotes versicolor), cobra (Naja naja) and crocodile (Gavialis gangeticus) were studied.