Dolphin class biology. Common bottlenose dolphin 2. However, dolphins are scientifically categorized as mammals, a distinction rooted in several fundamental biological characteristics. There are over 90 species of whales, dolphins and porpoises (cetaceans) found throughout the world’s oceans. Short-beaked common dolphin 4. But behind their charm, there is a profound scientific story about how they evolved and how their biological systems work. Long-beaked common dolphin 5. Of these, 53 species are known to inhabit Australian waters. While most have a general dolphin-shaped body, the shape of the head, pectoral fins, tail flukes and dorsal fin can vary enormously across the different species. Following the decline of the dinosaurs more than 50million years ago, the evolutionary process of whales and dolphins began Jan 18, 2026 · A dolphin is an aquatic mammal classified under the clade Odontoceti (toothed whales) and belongs to the family Delphinidae, which includes several species of oceanic dolphins. Some of thecommonly found dolphin species are listed below: 1. ikadfa jabv chp gmjvc tqejw ydqbz qljp imuikk tjen anq