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Sperm whales have the largest brain mass of any animal on Earth, averaging 8,000 cm 3 (490 in 3) and 7.8 kg (17 lb) in mature males. [28] The brain to body mass ratio in some odontocetes, such as belugas and narwhals, is second only to humans. [29] In some whales, however, it is less than half that of humans: 0.9% versus 2.1%. [citation needed]
A single fossil from Baja California indicates the family once inhabited warmer waters. [27] [56] [57] Acrophyseter skull. Ancient sperm whales differ from modern sperm whales in tooth count and the shape of the face and jaws. For example, Scaldicetus had a tapered rostrum. Genera from the Oligocene and Miocene had teeth in their upper jaws.
Whales do, however, lack short wavelength sensitive visual pigments in their cone cells indicating a more limited capacity for colour vision than most mammals. [51] Most whales have slightly flattened eyeballs, enlarged pupils (which shrink as they surface to prevent damage), slightly flattened corneas and a tapetum lucidum; these adaptations ...
The skim-feeders are right whales, gray whales, pygmy right whales, and sei whales (which also lunge feed). To feed, skim-feeders swim with an open mouth, filling it with water and prey. Prey must occur in sufficient numbers to trigger the whale's interest, be within a certain size range so that the baleen plates can filter it, and be slow ...
In humans, the vermiform appendix is sometimes called a vestigial structure as it has lost much of its ancestral digestive function. Vestigiality is the retention, during the process of evolution, of genetically determined structures or attributes that have lost some or all of the ancestral function in a given species. [1]
A researcher fires a biopsy dart at an orca.The dart will remove a small piece of the whale's skin and bounce harmlessly off the animal. Cetology (from Greek κῆτος, kētos, "whale"; and -λογία, -logia) or whalelore (also known as whaleology) is the branch of marine mammal science that studies the approximately eighty species of whales, dolphins, and porpoises in the scientific ...
Pitman, who has studied killer whales in Antarctica for over 10 years, said there's a similar divide between mammal- and fish-eating killer whales in those waters.
Homologous structures - structures (body parts/anatomy) which are similar in different species because the species have common descent and have evolved, usually divergently, from a shared ancestor. They may or may not perform the same function. An example is the forelimb structure shared by cats and whales.