Cetacean brains: How aquatic are they?

@article{Marino2007CetaceanBH,
  title={Cetacean brains: How aquatic are they?},
  author={Lori Marino},
  journal={The Anatomical Record: Advances in Integrative Anatomy and Evolutionary Biology},
  year={2007},
  volume={290}
}
  • L. Marino
  • Published 2007
  • Medicine, Biology
  • The Anatomical Record: Advances in Integrative Anatomy and Evolutionary Biology
The adaptation of cetaceans to a fully aquatic lifestyle represents one of the most dramatic transformations in mammalian evolutionary history. Two of the most salient features of modern cetaceans are their fully aquatic lifestyle and their large brains. This review article will offer an overview of comparative neuroanatomical research on aquatic mammals, including analyses of odontocete cetacean, sirenian, pinniped, and fossil archaeocete brains. In particular, the question of whether a… Expand
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References

SHOWING 1-10 OF 42 REFERENCES
Cortical complexity in cetacean brains.
  • P. Hof, R. Chanis, L. Marino
  • Biology, Medicine
  • The anatomical record. Part A, Discoveries in molecular, cellular, and evolutionary biology
  • 2005
TLDR
Data on brain size and hemisphere surface configuration in several cetacean species are summarized and an overview of the cytoarchitectural complexity of the cerebral cortex of the bottlenose dolphin is presented. Expand
Origin and evolution of large brains in toothed whales.
  • L. Marino, D. McShea, M. Uhen
  • Biology, Medicine
  • The anatomical record. Part A, Discoveries in molecular, cellular, and evolutionary biology
  • 2004
TLDR
It is shown that brain size increased significantly in two critical phases in the evolution of odontocetes, and was accompanied by a decrease in body size in Delphinoidea only by 15 million years ago. Expand
Brain Size Evolution
TLDR
This chapter explores the brain size evolution of marine mammals with a focus on encephalization Quotient, a measure of observed brain size relative to expected brain size derived from a regression of brain weight on body weight for a sample of species. Expand
Evolution of marine mammals: Back to the sea after 300 million years
  • M. Uhen
  • Biology, Medicine
  • Anatomical record
  • 2007
TLDR
The earliest representatives of these clades all show morphological features that indicate they were feeding while in the water, suggesting that feeding ecology is a key factor in the evolution of marine mammals. Expand
Skeletons of terrestrial cetaceans and the relationship of whales to artiodactyls
TLDR
Cladistic analysis of the skeletons of two early Eocene pakicetid cetaceans, the fox-sized Ichthyolestes pinfoldi, and the wolf-sized Pakicetus attocki, indicates that cetACEans are more closely related to artiodactyls than to any mesonychian, and supports monophyly of artiodACTyls. Expand
A Comparison of Encephalization between Odontocete Cetaceans and Anthropoid Primates
  • L. Marino
  • Medicine, Biology
  • Brain, Behavior and Evolution
  • 1998
TLDR
Results show that the encephalization level of Homo sapiens is still extraordinary relative to that of nonhuman species, but a subset of delphinid odontocetes are significantly more highly encephalized than the most highlyEncephalized anthropoid primates and narrow the gap in encephalizations between humans and nonhumans substantially. Expand
The anatomy of the brain of the bottlenose dolphin (Tursiops truncatus). Surface configurations of the telencephalon of the bottlenose dolphin with comparative anatomical observations in four other cetacean species
TLDR
The surface demarcation of the rhinencephalon and the cleavage of each hemisphere into concentric tiers are sharper and clearer in the cetacean brain than in any other mammalian brain. Expand
Morphogenesis of the brain in the harbour porpoise
TLDR
Investigation of reconstructions from serial sections of successive prenatal stages of the harbour porpoise revealed that a common ontogenetic plan regarding the chronological sequence of morphogenetic events exists in mammalian orders as different as primates and odontocetes. Expand
The Auditory Central Nervous System of Dolphins
TLDR
Although there have been no specific studies on hearing by the cetacean fetus, clearly other mammals have demonstrated a capability to hear in the womb well before birth. Expand
Magnetic resonance images of the brain of a dwarf sperm whale (Kogia simus)
TLDR
This paper represents the first MRI‐based anatomically labelled three‐dimensional description of the dwarf sperm whale brain and displays the proportions and positions of major neuroanatomical features. Expand
...
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2
3
4
5
...