List of four main types of reptilia found in the world. The types are: 1. Dinosaur 2. Tortoises and Turtles 3. Lizards 4. Snakes. Reptilia: Type # 1. Dinosaur: The word ‘dinosaur’ is a blend of the Greek terms ‘deinos’ (meaning terrible) and saurus (meaning lizard). Richard Owen coined the term dinosaur. The dinosaurs were divided into two main types; [...]
The below mentioned article provides biology notes on Class Osteichthyes. 1. The endoskeleton is cartilaginous in the embryonic stage, but in the adult forms more or less it is replaced by bones. Thus they have bony endoskeleton. They are ectothermic (cold blooded). There are about 25,000 species of bony fishes. 2. Caudal fin usually homocercal symmetrical (Gr. homos- alike). 3. [...]
The below mentioned article provides short notes on Class Chondrichtyes. 1. The fishes of this class bear cartilaginous endoskeleton. They are cold blooded (poikilothermous or ectothermic). There are about 600 species of cartilaginous fishes. 2. The skin is tough, containing minute placoid scales, which are dermal in origin. 3. Except in the Chimaeras, the gills are not covered by an [...]