<P> The Eocene Epoch ranged from 56 million years to 33.9 million years ago . In the Early - Eocene, life was small and lived in cramped jungles, much like the Paleocene . There was nothing over the weight of 10 kilograms . Among them were early primates, whales and horses along with many other early forms of mammals . At the top of the food chains were huge birds, such as Paracrax . The temperature was 30 degrees Celsius with little temperature gradient from pole to pole . In the Mid-Eocene, the Circumpolar - Antarctic current between Australia and Antarctica formed which disrupted ocean currents worldwide and as a result caused a global cooling effect, shrinking the jungles . This allowed mammals to grow to mammoth proportions, such as whales which, by that time, were almost fully aquatic . Mammals like Andrewsarchus were at the top of the food - chain . The Late Eocene saw the rebirth of seasons, which caused the expansion of savanna - like areas, along with the evolution of grass . The end of the Eocene was marked by the Eocene - Oligocene extinction event, the European face of which is known as the Grande Coupure . </P> <P> The Oligocene Epoch spans from 33.9 million to 23.03 million years ago . The Oligocene featured the expansion of grass which had led to many new species to evolve, including the first elephants, cats, dogs, marsupials and many other species still prevalent today . Many other species of plants evolved in this period too, such as the evergreen trees (Conifers originated during the Carboniferous and dominated during the Mesozoic era - what kind of evergreen trees evolved during the Oligocene?). A cooling period was still in effect and seasonal rains were as well . Mammals still continued to grow larger and larger . Paraceratherium, the largest land mammal to ever live evolved during this period . </P> <P> The Neogene spans from 23.03 million to 2.58 million years ago . It features 2 epochs: the Miocene, and the Pliocene . </P> <P> The Miocene epoch spans from 23.03 to 5.333 million years ago and is a period in which grass spread further, dominating a large portion of the world, at the expense of forests . Kelp forests evolved, encouraging the evolution of new species, such as sea otters . During this time, perissodactyla thrived, and evolved into many different varieties . Apes evolved into 30 species . The Tethys Sea finally closed with the creation of the Arabian Peninsula, leaving only remnants as the Black, Red, Mediterranean and Caspian Seas . This increased aridity . Many new plants evolved: 95% of modern seed plants evolved in the mid-Miocene . </P>

Which of the following experienced major radiations during the cenozoic