Reimei Era (黎明代)
The Reimei Era — known as Reimeidai（黎明代）, the "Era of Dawn" — spans 60 to 30 million years ago. It opens in the aftermath of the catastrophic Kasei extinction, when fire and ash gave way to renewal. In this new world, freed from ancient reptilian empires and burdened ecosystems, mammals and birds surged forth to claim the empty niches.
It was during the Reimeidai that the world began to look familiar in form, if not yet in inhabitants. The continents now stood apart, their edges firmed by millions of years of separation. Isolation began to mold evolution more sharply. What had once been similar clades now bent into strange and wondrous forms across the scattered lands.
Key Features of the Reimei Era
- Widespread radiation of placental mammals, with Laurasiatheres, Archontaglires, Afrotheres, and Xenarthrans all developing along separate tracks
- Rise of modern bird orders and the disappearance of most archaic pterosaur and reptilian lineages
- Subtropical and temperate forests flourish; grasslands begin to develop in localized pockets
- Climatic warmth characterizes much of the era, though slow cooling begins near its close
- Endemic ecosystems define each continent — once-pangean fauna now evolve in splendid isolation
Continental Biogeography (60–30 Mya)
Archaeo-Bōkō
Climate: Subtropical to Temperate- Flora: Expanding temperate deciduous forests, early grasslands in drier uplands, angiosperm dominance
- Fauna: Diversifying Laurasiatheres — early perissodactyls, artiodactyls, creodonts, and giant flightless birds
Archaeo-Teishin
Climate: Tropical to Subtropical- Flora: Tropical rainforests, fruiting trees, early canopy vines
- Fauna: Radiating Archontaglires — ancestral rodents, primates, and lagomorphs; arboreal insectivores
Archaeo-Gonan
Climate: Tropical- Flora: Dense angiosperm jungles, cycads, flowering shrubs and aquatic vegetation
- Fauna: Afrotheres (elephantiforms, sengis), xenarthrans (edentates, early sloth-relatives), tropical crocodilians
Archaeo-Tousai
Climate: Subtropical- Flora: Mixed forests, palm forests, early flowering shrubs in undergrowth
- Fauna: Rodentiform immigrants, insectivorous mammals, archaic bird lineages persisting
Archaeo-Shinchuu
Climate: Temperate- Flora: Hardwood forests, seasonal flowering meadows
- Fauna: Multituberculates near extinction, small gliding mammals, shorebirds and seed specialists
Archaeo-Kouchuu (Kōbō)
Climate: Temperate- Flora: Angiosperm-conifer mix, deciduous hardwoods, seasonal wildflowers
- Fauna: Relict tritylodontid insectivores, endemic birds, slow diversification of mammalian herbivores
Chichū
Climate: Subtropical- Flora: Riverine vegetation, vines, podocarps, flower-dense forests
- Fauna: Arboreal marsupials, fossorial insectivores, flighted and flightless birds in mixed habitats
Chishi
Climate: Subtropical- Flora: Ginkgo relicts, seed ferns in decline, new angiosperm trees rising
- Fauna: Endemic mammalian clades, burrowing herbivores, seed-cracking birds
Boshu
Climate: Tropical- Flora: Mangrove thickets, flowering coastal plants, cycads in inland zones
- Fauna: Amphibious mammals, coastal crocodilians, aquatic foragers and waders
Shinshin
Climate: Subtropical- Flora: Moist forests with seasonal bloomers, ferns and epiphytes
- Fauna: Arboreal omnivores, insectivores with derived hearing, gliding reptiles in decline
Kyougai
Climate: Subtropical- Flora: Coastal flowering groves, forest-steppe transitions inland
- Fauna: large frugivorous birds, endemic synapsid remnants
Heiyū, Zhamo, Lomba, Chūin, Chishu
Climate: Boreal to Polar- Flora: Boreal forests, alpine shrubs, tundra grasses beginning to spread
- Fauna: Cold-adapted mammals, early ungulates with thick coats, carnivorous birds of prey