240 million years PE
Another 12 million years have passed, and Serina is now nearing the end of the Pangeacene. The large global landmass which so gave this epoch its name has begun to divide into two major continents which are drifting apart once again across the surface of the world of birds.
The climate becomes overall wetter as the large landmass breaks up, causing the harsh interior desert to recede slightly. As vegetation continues to absorb the great quantities of carbon released during the highly volcanic Thermocene-Pangeacene boundary, Serina also continues to cool. Significant snowfall becomes more frequent in temperate regions and a small ice cap begins to form over the southpole. The belt along the equator which supports tropical forests shrinks back, though only by a few degrees of latitude for now. Volcanism overall remains low through the end of the Pangeacene, even as the continents shift and break apart, though earthquakes - some of very large scales - and isolated volcanic eruptions will cause localized extinction events over the next few million years.
As the climate returns to a cooler state, life must adapt or perish. Many species of tribbets and ectothermic birds that truly cannot handle cold winters shrink toward the equator along with their habitats, but at least a few representatives of most groups will adapt to survive in a changing climate, evolving to hibernate or otherwise go dormant through the cold seasons. Most tribbats have so far failed to adapt to cooler regions, likely due to the constant dependence of most forms on the availability of fruits, but vagrant predatory forms begin to spread north and south. At the end of the Pangeacene the first truly cold-adapted tribbetheres appear out of the molodont clade, with thick fur to insulate them against snow and wind. Circuagodonts begin to diversify dramatically into many distinct genera, some of which begin a reversion toward a more omnivorous diet. Razorgrass savannahs are in a rapid decline as a result of circuagodont grazing and more abundant rainfall that allows the growth of more competitive puffgrasses.
Many of the serezelles and other herbivorous, cursorial and quadrupedal changeling birds which proliferated at the beginning of the Thermocene have now died out, displaced by molodont tribbetheres. A handful of relic species persist in the tropics, though their long-term survival is uncertain, but more successful have been clade of carnivorous forms that resemble a strange admixture of antelope and storks called spearrunners. They are believed to have evolved from a serezelle-like bird which existed before the appearance of the circuagodonts and supplemented an herbivorous diet with insects and small animals during the dry season when razorgrass dominated the open plains across most of the interior. Like the ancient takareweas of the Kyran Islands, they hunt by running down their prey and catching it in a long pointed bill, usually swallowing it whole.
Cooling polar regions result in a productivity boom to the sea, as polar phytoplankton blooms support more and larger species of dolfinches and other marine animals than existed in the warmer, less productive seas of the earlier Pangeacene.
Myrmecophyte forests meanwhile are undergoing another evolutionary breakthrough as the bond between sunflower trees and their ant symbiotes becomes increasingly intertwined. A new group of ant trees is evolving which take the symbiosis to what may be its pinnacle, with both the tree and its insect partners now completely dependent on each other for survival. They have in effect become a superorganism, linked from birth to death, a hybrid of plant and animal with a complex life cycle unlike anything before seen on Serina.
Lastly, intelligence has arisen near the equator, as a culture of social, tool-using predators begins for the first time to question the world around them.
Evolution marches on as we reach the end of the Pangeacene. As temperatures on the world of birds go down, the derivity of the natives rises ever higher.