Teeth: Types, Dental Formula and Tooth Anatomy

Each tooth is embedded in a socket of jaw bone. Most of the animals including humans have two sets of teeth during their life. First set is of temporary milk or deciduous teeth, which is replaced by a set of ..

Types of Animal Tissues

In all the animals, tissues develop from the embryonic germ layers during the blastula (early stage of embryonic development) phase. On the basis of germ layers, all animals except Porifera and Protozoa; there are either two or three germ layers. ..

Salient Features and Types of Mammals: Monotremes, Marsupials, Eutherians

Both birds and mammals have evolved from a reptile ancestor. In terms of evolution, mammals are most advanced organisms found in almost all habitats in Earth’s biosphere including polar ice caps, deserts, mountains, forests, grasslands and dark caves. Common features ..

Class Aves: Origin, Adaptations and Key Features

Sometime during the early Jurassic, two groups of reptiles gained the ability to fly and one of these groups later gave rise to the Aves (birds). They developed a range of adaptations that enabled flight such as feathers, anterior limbs ..

Reptiles

Reptiles are the first entirely terrestrial vertebrate class, totally independent from the aquatic habitat for survival. They have excellent evolutionary innovation to get them rid of water life. Their skin is keratinized and impermeable to water whereas amphibian skin is ..

Amphibians: Examples, Features and Adaptations to Terrestrial Environment

Amphibians were the first vertebrates to venture out onto land. Early amphibians retained many fish-like characteristics but during the Carboniferous period amphibians diversified. Even today, Amphibians live a dual life. They are totally aquatic during their larval stage and partially ..

Cartilaginous Fish and Bony Fish Examples

All the true fishes have been classified into two main classes as follows: Chondrichthyes: These are the fishes with soft cartilaginous skeletons. Examples are sharks, rays, dog-fish, skates, sturgion Osteichthyes: These are fishes with bony skeleton. Examples are Tuna, Sardines, ..

Difference Between Agnatha and Gnathostomata

With currently 64000, species, majority of the members of Phylum Chordata belong to sub-phylum Vertebrata. All vertebrates possess notochord during the embryonic period only and later it is replaced by bony vertebral column. Further, the vertebrates have a ventral muscular ..

Echinoderms

Members of Echinodermata (Spiny bodied) have an endoskeleton of calcareous ossicles. Starfish, sea cucumbers (holothurians), sea urchins and brittle stars are examples of echinoderms. All echinoderms are marine animals. They live in salt water. Salient notes on Echinoderms Thorny Animals ..

Mollusca

Phylum Mollusca is the second largest animal phylum after Arthropoda. They are terrestrial or aquatic (both marine and freshwater). Members of this phylum include snails, octopuses, squids, oysters etc. Soft body of Molluscs The word “mollusc” means “soft thing”. Molluscs ..