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Origin And Evolution Of Large Brains In Toothed Whales, Lori Marino, Daniel W. Mcshea, Mark D. Uhen
Origin And Evolution Of Large Brains In Toothed Whales, Lori Marino, Daniel W. Mcshea, Mark D. Uhen
Veterinary Science and Medicine Collection
Toothed whales (order Cetacea: suborder Odontoceti) are highly encephalized, possessing brains that are significantly larger than expected for their body sizes. In particular, the odontocete superfamily Delphinoidea (dolphins, porpoises, belugas, and narwhals) comprises numerous species with encephalization levels second only to modern humans and greater than all other mammals. Odontocetes have also demonstrated behavioral faculties previously only ascribed to humans and, to some extent, other great apes. How did the large brains of odontocetes evolve? To begin to investigate this question, we quantified and averaged estimates of brain and body size for 36 fossil cetacean species using computed tomography and …
A Comparison Of Encephalization Between Odontocete Cetaceans And Anthropoid Primates, L. Marino
A Comparison Of Encephalization Between Odontocete Cetaceans And Anthropoid Primates, L. Marino
Veterinary Science and Medicine Collection
There have been very few studies of brain size and encephalization in cetaceans and essentially none that have made direct quantitative comparisons of cetaceans and another mammalian group using large normative samples. In the present study two different measures of encephalization were calculated and used to rank and compare 21 odontocete species and 60 anthropoid primate species. Comparisons were made both within and between the two groups. Results show that the encephalization level of Homo sapiens is still extraordinary relative to that of nonhuman species. Nevertheless, a subset of delphinid odontocetes are significantly more highly encephalized than the most highly …