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The evolution of cetaceans is thought to have begun in the Indian subcontinent from even-toed ungulates (Artiodactyla) 50 million years ago (mya) and to have proceeded over a period of at least 15 million years. [ 2 ] Cetaceans are fully aquatic marine mammals belonging to the order Artiodactyla and branched off from other artiodactyls around ...
Cetacea (/ sɪˈteɪʃə /; from Latin cetus ' whale ', from Ancient Greek κῆτος (kêtos) ' huge fish, sea monster ') [3] is an infraorder of aquatic mammals belonging to the order Artiodactyla that includes whales, dolphins and porpoises. Key characteristics are their fully aquatic lifestyle, streamlined body shape, often large size and ...
The Cetaceans Portal. Cetacea (/ sɪˈteɪʃə /; from Latin cetus ' whale ', from Ancient Greek κῆτος (kêtos) ' huge fish, sea monster ') is an infraorder of aquatic mammals belonging to the order Artiodactyla that includes whales, dolphins and porpoises. Key characteristics are their fully aquatic lifestyle, streamlined body shape ...
Archaeoceti ("ancient whales"), or Zeuglodontes in older literature, is a paraphyletic group of primitive cetaceans that lived from the Early Eocene to the late Oligocene (50 to 23 million years ago). [1] Representing the earliest cetacean radiation, they include the initial amphibious stages in cetacean evolution, thus are the ancestors of ...
Evidence of common descent of living organisms has been discovered by scientists researching in a variety of disciplines over many decades, demonstrating that all life on Earth comes from a single ancestor. This forms an important part of the evidence on which evolutionary theory rests, demonstrates that evolution does occur, and illustrates ...
The traditional theory of cetacean evolution was that cetaceans were related to the mesonychian. These animals had unusual triangular teeth very similar to those of primitive cetaceans. This is why scientists long believed that cetaceans evolved from a form of mesonychian.
List of cetaceans. Cetacea is an infraorder that comprises the 94 species of whales, dolphins, and porpoises. It is divided into toothed whales (Odontoceti) and baleen whales (Mysticeti), which diverged from each other in the Eocene some 50 million years ago (mya). Cetaceans are descended from land-dwelling hoofed mammals, and the now extinct ...
The limbs of more aquatic Eocene cetaceans did not preserve very well. Ambulocetus demonstrated that cetaceans swam by flexing the spine up and down (undulation) before they had evolved the tail fluke, forelimb propulsion evolved relatively late, and that cetaceans went through an otter-like phase with spinal undulation and hindlimb propulsion ...