We all see animals around us and even keep them as pets because we love them also. Most of these animals are vertebrates – they all have backbones.
Fact 1 Meaning Of Vertebrate
The word vertebrate means joint of the spine. It is derived from the Latin word “vertebrates” which means joint of the spine. It is related to the word vertebra which refers to any of the segments or bones of the spinal column.The backbone of animals are composed of separate segments or mobile joints. These series of large bones help them to move, run, swim, fly or climb. This is also called vertebral column. Animals that have this vertebral column are known as vertebrates.
Over 530 million years ago Vertebrates evolved during the Cambrian period. The species that are included under this sub-phylum or sub-division are found from the Polar regions to the Tropical areas. They vary in sizes and colors starting from the tiniest fishes to huge elephants and blue whales. The uniqueness of Vertebrates is they have adapted themselves to all kinds of environments. They live in the waters, lands, trees as well as the air. Vertebrates are mostly herbivores but some are omnivores also.
Fact 3 Classification Of Vertebrates
Vertebrates are classified into 5 groups. The differentiation is done according to the skin covering, reproduction method, maintenance of body temperature and specific characteristics of the limbs which help in movements. However the main feature of all vertebrates is the vertebral column in which there is a stiff rod of uniform composition that is found in all chordates and has been replaced by a segmented series of stiffer elements separated by mobile joints. These are known as invertebral derived from evolutionary and embryonically from the notochord.
Fact 4 The 5 Classes Of Vertebrates
The five classes of vertebrates are the following:
Fact 5 Specific Characteristics Of The Classes
Fish – Fish are aquatic, ectothermic vertebrates. The skin of most fish is covered with scales that may vary in size or color. They use their fins for swimming which act as their limbs. Since they do not have a nose, they breathe through their gills. Fish lay eggs inside the water.
Amphibians – Amphibians are ectothermic vertebrates. Their skin is either smooth like the frog or rough like a toad. Their skin essentially requires moisture that helps them to breathe. Amphibians lay their eggs in water. When the eggs hatch, they have an intermediate form known as tadpoles and these breathe with the gills. Gradually they grow up into adult frogs or toads that breathe air and can live outside water also. Their hearts have 3 chambers.
Reptiles – Reptiles also belong to the ectothermic group of vertebrates. Their skin has scales. Most of the reptiles have 3-chambered hearts except the alligators and crocodiles that have 4 chambers. Most of the reptiles have claws on their feet except for the legless lizards. Reptiles are the first vertebrate animals to develop amniotic eggs that allow them to lay eggs on land according to evolutionary theory.
Birds – Birds have different features. They are endothermic vertebrates. Their skin is covered with feathers. The bones are very light and are hollow inside. The forelimbs are modified as wings and the hind legs are used for perching. Birds mostly build nests and lay their eggs in their nests. They take care of their babies till they are strong enough to fly and find food for themselves.
Mammals – Mammals are endothermic vertebrates. They have hair that varies according to species. They have sweat glands and mammary or milk-secreting glands for which they are called mammals. They have sebaceous glands and different types of teeth.