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Vertebrates (/ ˈ v ɜːr t ə b r ɪ t s,-ˌ b r eɪ t s /) [3] are animals with a vertebral column (backbone or spine), and a cranium, or skull. The vertebral column surrounds and protects the spinal cord, while the cranium protects the brain. The vertebrates make up the subphylum Vertebrata with some 65,000 species, by far the largest ...
Each vertebra (pl.: vertebrae) is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spinal segment and the particular species.
A mammal (from Latin mamma 'breast') [1] is a vertebrate animal of the class Mammalia (/ m ə ˈ m eɪ l i. ə /).Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three middle ear bones.
Animals form a clade, meaning that they arose from a single common ancestor. Over 1.5 million living animal species have been described, of which around 1.05 million are insects, over 85,000 are molluscs, and around 65,000 are vertebrates. It has been estimated there are as many as 7.77 million animal species on Earth.
It is the largest class of vertebrates in existence today. Osteichthyes is divided into the ray-finned fish ( Actinopterygii ) and lobe-finned fish ( Sarcopterygii ). The oldest known fossils of bony fish are about 420 million years ago, which are also transitional fossils , showing a tooth pattern that is in between the tooth rows of sharks ...
A forelimb or front limb is one of the paired articulated appendages attached on the cranial end of a terrestrial tetrapod vertebrate's torso. With reference to quadrupeds, the term foreleg or front leg is often used instead. In bipedal animals with an upright posture (e.g. humans and some other primates), the term upper limb is often used.
A silvery 10-foot long creature, the oarfish has fueled fishermen's tales of sea serpents — and in some cultures has been a portent of natural disasters.
Parthenogenesis does not apply to isogamous species. [44] Parthenogenesis occurs naturally in aphids, Daphnia, rotifers, nematodes, and some other invertebrates, as well as in many plants. Among vertebrates, strict parthenogenesis is only known to occur in lizards, snakes, [45] birds, [46] and sharks. [47]