The existence or absence of vertebrates is one of the ways life is characterised. Vertebrates and invertebrates are thought to have descended from a common ancestor that lived roughly 600 million years ago.
True vertebrates first appeared 525 million years ago, and since then, they have evolved into a vast lineage which contains armoured fish and huge sauropods, as well as woolly mammoths and modern man.
Vertebrates
Birds, fishes, mammals, lampreys, reptiles and amphibians are all classified as vertebrates (Vertebrata). Vertebrates include a vertebral column with many vertebrae which create a backbone in place of the notochord. The vertebrae protect and surround a nerve cord while also providing structural support to the animal.
Vertebrates have paired sensory organs, a well-developed head, and a separate brain protected by a skull. They also feature a chambered heart, a muscular pharynx containing slits and gills (the slits and gills in terrestrial vertebrates are considerably changed), a muscularis stomach, and a chambered respiratory system.
In vertebrates, the vertebral column is one of the group’s distinguishing features. A notochord is found early in the development of most vertebrates. The notochord is a long, flexible rod that runs the length of body. The notochord is gradually replaced by a succession of vertebrae that make up the vertebral column as the animal grows.
The evolution of jaws was a watershed moment in vertebrate evolution. Vertebrates with jaws were able to grab and consume larger prey than their jawless forefathers. Jaws are thought to have evolved as a result of changes to the first or second gill arches, according to scientists. This modification is assumed to have evolved as a technique to improve gill ventilation at first. The structure later served as jaws as muscles developed and the gill arches curved forward. Only the lampreys are the only surviving vertebrates without jaws.
Vertebrates Explanation
Vertebrates are classified as members of the Chordata family. In addition, vertebrates are the most powerful living beings. This is because the backbone and spinal structure are in good shape. Humans are also members of the vertebrate family. The vertebra in humans is made up of 33 well-stacked bones which are tightly linked with one another.
Basic characteristics are shared by all Vertebrates in the Chordata family. The ventral muscular heart is found in vertebrates. Furthermore, depending on the functionality of the chambers, the heart has 2, 3, or 4 chambers in various organisms. Vertebrates have kidneys, which help with excretion, as well as an osmoregulation system.
Classification of Vertebrates
Class Mammalia
Mammalian hearts have four chambers and warm blood. They usually give birth to their progeny, although there are exceptions, such as the Echidna, which reproduces by depositing eggs. Such vertebrates have a wide range of habitats.
Mammary glands are found in order to feed the infants. Mammals have external pinnas and functioning limbs. Internal fertilisation is common in these species. Kangaroo, dolphin, whale, and platypus are among examples.
Class Reptilia
Snakes, crocodiles, tuataras, and turtles are examples of reptiles. The fact that reptiles are ectothermic is a distinguishing attribute. Snakes are nonetheless classified as tetrapods despite the absence of visible limbs. This is related to the fact that snakes descended from limbless predecessors.
Class Aves
This group of vertebrae includes birds. Aves are distinguished by their feathered bodies and forelimbs, which developed as wings for flight. The Ostrich is the exception in this regard, as it is unable to fly.
Air cavities can be discovered in bones, and the digestive tract also has chambers. Vultures, pigeons, crows, and other birds are examples.
Class Pisces
Fish having scales all over their bodies belong in this category. These are oviparous animals with only gills for breathing. Fish have a two-chambered heart and a cartilage skeleton. Sharks, on the other hand, have a cartilage and bone skeleton.
Class Amphibia
Ectothermic tetrapods like frogs, toads, and salamanders are amphibians. The breeding behaviour of amphibians and reptiles distinguishes them from one other. Because their eggs are shell less, most amphibians require a body of water to reproduce. They also go through metamorphosis, in which the young change from fully aquatic larvae (having gills and fins) to terrestrial adults.
Vertebrate Brain
Central nervous system of vertebrates is dominated by the brain. The brain is in the front, in the head, of vertebrates (and other animals). It is near the key senses of vision, taste, hearing, balance, and smell and is protected by the skull. As an animal travels forward, its senses gather information about its environment, which is sent straight to the brain.
Conclusion
Vertebrates include a vertebral column with many vertebrae which create a backbone in place of the notochord.The vertebra in humans is made up of 33 well-stacked bones which are tightly linked with one another.The heart has 2, 3, or 4 chambers in various organisms.
The vertebrates are classified as
- Class Mammalia
- Class Reptilia
- Class Amphibia
- Class Pisces
- Class Aves