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Jan 17, 2018 · The pinnipeds are the youngest group of marine mammals, originating about 25 million years ago during the late Oligocene period. They are arctoid carnivores within the order Carnivora, and appear to have evolved from primitive bears. They are therefore closely related to modern bears, as well as the mustelids (weasels, skunks, otters and kin).
May 21, 2007 · Marine Mammal Diversity. Living groups of marine mammals vary greatly in their diversity. Rice (1998; Table 1 therein) reports that living Cetacea include 83 species in 39 genera; living Pinnipedia include 36 species in 21 genera; and Recent Sirenia include 5 species in 3 genera. Since then, several new species of cetaceans have been described ...
Apr 16, 2015 · April 16, 2015. The oceans are teeming with tetrapods—“four-legged” birds, reptiles, mammals and amphibians—that have repeatedly transitioned from the land to the sea, adapting their legs ...
As that bipedal ape evolved into what would become us, other mammals came and went. Most had to adapt to yet another global climate change about 2.5 million years ago, triggered in part by the ...
Nov 15, 2019 · Abstract. Early Cetacea are classified as Archaeoceti (six families), and their fossils reveal the morphological and functional evolution of early, terrestrial Artiodactyla to fully aquatic Cetacea over 15 million years during the Eocene (~52 Mya). The evolution of modern Cetacea (Neoceti: Mysticeti and Odontoceti) began in the late Eocene (~37 ...
Sep 24, 2014 · Although land-based mammals were increasing in diversity, few or none were present in the oceans. The basic hypothesis is that the early whale-like artiodactyls, like Indohyus and Pakicetus were land-based (terrestrial) mammals that spent most of their time near the water's edge. Over time, they adapted to the niches in the ocean.
Why did it take long before the rise of marine mammals? Thermal demands of living in cold water can only be met by relatively large mammals. When did large mammals appear?
