How are the vertebrates are further divided by divisions? Write the differences between them.

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answered Jan 7, 2023 by Sakshitripathi (70.4k points)
selected Jan 9, 2023 by AnshulChandore

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Subphylum Vertebrata is divided into two divisions, Agnatha and Gnathostomata.
Agnatha includes jawless fish-like aquatic vertebrates without paired appendages. Notochord persists in the adult.
Agnatha includes one important class – Cyclostomata.
Gnathostomata includes jawed vertebrates with paired appendages. Notochord is replaced partly or wholly by the vertebral column.
Gnathostomata includes jawed fishes (Pisces) and Tetrapoda ( amphibia, reptilia, aves and mammals).The superclass Pisces includes all fishes which are essentially aquatic forms with paired fins for swimming and gills for respiration. Pisces includes cartilaginous fishes (Chondrichthyes) and bony fishes (Osteicthyes).