Which Group Of Animals Are The Earliest Land Vertebrates

What is a Vertebrate?

A Vertebrate is an animate being that has a courage.

Fifty-fifty though vertebrates are a various group of animals, but effectually 50,000 species accept been identified which is a very small-scale fraction of all brute species. Vertebrates include all animals that accept a backbone.

Reptiles and amphibians are vertebrates every bit well as mammals, birds and fish. They all have a flexible support column to which other body structures are attached.

The outset vertebrates were primitive fish that business relationship for more than half of all living vertebrate species. Tetrapods are the principal cadre of vertebrates and it was the earliest tetrapods that first adult limbs and left that water to begin life on country. Those who left the water began to populate the country, take to the skies and some even returned to the water.

One of the ancestors of all vertebrate species was a small creature chosen a Pikaia who looked like a small eel with tail-fins and measured effectually one.5 inches (5 centimetres) in length. The Pikaia was the get-go known Chordate (an animal with a stiff supporting rod (notochord) along its back). In after animals, the notochord developed into the backbone.

Fossil remains of the Pikaia were found in the 530 millions years old mudstone deposits of the Burgess Shale in Canada.

Main Vertebrate Groups

Gnathosomata – these are vertebrates with jaws and include all land vertebrates and all fish except Lampreys and Hagfish.

Elasmobranchii – these are cartilaginous fish such as sharks and rays which are jawed fish with a skeleton made from cartilage instead of bone.

Osteichthyes – these are bony vertebrates and include all vertebrates with a mineralised skeleton such as mammals, birds, reptiles, amphibians and most fish.

Tetrapods – these are bony vertebrates with iv limbs or appendages. The beginning land-living vertebrate tetrapods include the earliest limbed vertebrates and all of its descendants including those that have since lost their limbs such as snakes.

Amphibians – these are cold-blooded tetrapods with porous, glandular skin and includes frogs, toads, salamanders and newts who are descendants of early tetrapods that did not develop an amnion (waterproof egg membrane).

Amniotes – these are tetrapods whose embryo grows within a waterproof membrane chosen an amnion, which enables life exterior of the water.

Reptiles – these are amniotes with thick peel and bony epidermal scales whose eggs have a mineralised shell. This grouping includes warm-blooded birds and scaly cold-blooded reptiles.

Lepidosaurs – these are reptiles that shed their skin in either large pieces are as a whole. These include tuataras, snakes, lizards and worm lizards.

Archosaurs – these are reptiles whose teeth are sunken into sockets such as birds and crocodiles.

Birds – these are archosaurs with symmetrical flying feathers. Many have shared features including a bony, toothless nib/nib and a keeled breastbone.

Mammals – warm-blooded animals which give birth to their immature. The young feed on their mothers milk.

Anatomy diagrams of vertebrates

Domestic dog

Horse

Manatee

List of Vertebrates

This by no means a comprehensive listing of vertebrate animals but is a selection of the near popular vertebrates featured on this website.

Source: https://animalcorner.org/vertebrates/

Posted by: davisvien1961.blogspot.com

Share this post