Key differences, features, and comparative analysis of Class and Hallmarks.
| Class | Hallmarks | Examples |
|---|---|---|
| Cyclostomata | Jawless; circular sucking mouth; no scales/paired fins; ectoparasites on fish; cartilaginous skeleton | Petromyzon (lamprey), Myxine (hagfish) |
| Chondrichthyes | Marine; cartilaginous endoskeleton; placoid scales; ventral mouth; no air bladder so must swim; internal fertilisation | Scoliodon (dogfish), Pristis (sawfish), Carcharodon (great white), Trygon (sting ray) |
| Osteichthyes | Bony endoskeleton; cycloid/ctenoid scales; air bladder regulates buoyancy; operculum over gills; mostly external fertilisation, oviparous | Labeo (rohu), Catla, Clarias (magur), Exocoetus (flying fish), Hippocampus (sea horse) |
| Amphibia | Live on land & water; moist skin (no scales); two pairs of limbs; 3-chambered heart; external fertilisation, oviparous | Rana (frog), Bufo (toad), Hyla (tree frog), Salamandra, Ichthyophis (limbless) |
| Reptilia | Creeping; dry, scaly skin; mostly 3-chambered heart (crocodile 4); cold-blooded; internal fertilisation; lay shelled eggs on land | Chelone (turtle), Testudo (tortoise), Naja (cobra), Crocodilus, Hemidactylus (wall lizard) |
| Aves (birds) | Feathers; forelimbs → wings; beak; 4-chambered heart; warm-blooded; bones pneumatic (air-filled); oviparous | Corvus (crow), Columba (pigeon), Struthio (ostrich), Neophron (vulture) |
| Mammalia | Mammary glands (milk); hair/fur; external ears (pinna); 4-chambered heart; warm-blooded; mostly viviparous | Ornithorhynchus (egg-laying platypus), Macropus (kangaroo), Pteropus (flying fox), Balaenoptera (blue whale), Panthera, Homo |
This comparison table is part of the chapter notes for Animal Kingdom. Get complete notes, flashcards, active recall sheets, and test prep modes: