Placentation in mammals once grouped as insectivores
نویسندگان
چکیده
منابع مشابه
Placentation and maternal investment in mammals.
The mammalian placenta exhibits striking interspecific morphological variation, yet the implications of such diversity for reproductive strategies and fetal development remain obscure. More invasive hemochorial placentas, in which fetal tissues directly contact the maternal blood supply, are believed to facilitate nutrient transfer, resulting in higher fetal growth rates, and to be a state of r...
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Embryonic development in nonmammalian vertebrates depends entirely on nutritional reserves that are predominantly derived from vitellogenin proteins and stored in egg yolk. Mammals have evolved new resources, such as lactation and placentation, to nourish their developing and early offspring. However, the evolutionary timing and molecular events associated with this major phenotypic transition ...
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Although insectivores have traditionally been thought of as primitive mammals with few specializations, recent studies have revealed great diversity in the sensory systems and brain organization of members of this mammalian order. The present article reviews some of these findings in three insectivore families that are thought to form a monophyletic group. These include hedgehogs (Erinaceidae),...
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The phenomenon of terrestrial mammals as predators in marine intertidal communities, and thus as agents of energy transfer from sea to land, is poorly understood. We review here the evidence for terrestrial mammals intentionally entering the ocean shore at low tide in order to prey on living marine invertebrates, fish, algae, and seagrasses. We introduce the term ‘maritime mammals’, defined as ...
متن کاملComparative Placentation
The ancestry of horses from five-toed species via the small Eohippus of the American continent has been a prime topic of study for evolutionary biologists. It is best traced in two contributions: by Simpson (1951), and by Thenius & Hofer (1960). Coming from the American continent, the equid ancestors distributed to Eurasia while speciating into the extant members during their expansion to the W...
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ژورنال
عنوان ژورنال: The International Journal of Developmental Biology
سال: 2010
ISSN: 0214-6282
DOI: 10.1387/ijdb.082830ac