In the birds vertebral column compound structure is present. It is called Synsacrum. It is formed by the fusion of 14 to 16 vertebrae. Those vertebrae are one last thorasic…
The body wall of birds has three regions, Skin, Muscles and Perito­neum.   The skin is dry. It shows upper stratum corneum, which has flat cornified cells. The feathers cover…
Based on characters of  Aves Class is divided into 2 sub-classes. Sub class: i) Archeornithes and Subclass ii) Neornithes   1. Sub class Archeornithes:   In this subclass extinct birds…
AN INTRODUCTION TO AVES (BIRDS)   Birds (AVES) are highly evolved vertebrates. In the Jurassic period of Mesozoic era the Birds first appeared. They evolved from Ornithischian dinosaurs of Reptilian…
In Reptiles the “organs of Jacobson” are well developed sac like chambers. They lie below the nasal cavity and above the buccal cavity. Each organ is a blind pocket. It…
The trunk of chelonia is enclosed by Shell which has two parts, a dorsal carapace and a flat ventral plastron, joined on the sides. This is called tortoise shell.  …
Snakes consisting Poison Apparatus by the contraction of digastric muscles in Poison Apparatus in snake the mouth is opened. Then the lower jaw moves forward. The sphenopterygoid muscles contract which…
It has a pair of poison glands, or ducts and a pair of fangs. The poison glands are present on the upper jaw. The poison glands are the superior labial…
Based on characters Reptiles is divided into Four sub class   ANAPSIDA PARAPSIDA DIAPSIDA SYNAPSIDA   1. Sub-class: Anapsida:   The skull of Reptiles are made by solid roof. In…
AN INTRODUCTION TO REPTILES   In the carboniferous period of palaeozoic era “Reptiles” arose from Labyrinthodont Amphibians. In the Mesozoic era “Reptiles” dominated the entire world and that era is…

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