Shijin Era (四神代, Shijindai)
The Shijin Era represents the period during which the broken supercontinent of Pan-Erthas reorganized into four distinct continental landmasses. Climate gradients steepened, evolutionary divergence accelerated, and entire biological classes began to establish continent-specific presences. The name “Shijin” — referencing the Four Divine Beasts of later elven philosophy — came to symbolize the four-fold division of the world.
Continents
Archaeo-Daitō（Thadh, Kiin, Chūin, Jinchū, Jinshi）
Climate: Subtropical (Thadh–Jinchū), Tropical (Jinshi)- Dominant Plant Classes:
- Lycopodiopsida — clubmosses, primarily in wetter lowlands
- Polypodiopsida — true ferns in riverine and forest understories
- Equisetopsida — horsetails in open floodplains
- Cycadopsida — cycads becoming widespread in uplands and seasonal forests
- Pinopsida — early conifers spreading into drier and cooler regions
- Ginkgoopsida — rare but present in uplands
- Dominant Animal Classes:
- Amphibia — especially large temnospondyls in subtropical wetlands
- Synapsida — pelycosaurs and early therapsids adapting to drier plains
- Reptilia — early diapsids expanding in niche diversity
- Insecta — high insect diversity, especially orthopterans, coleopterans, and early dipterans
- Arachnida — scorpions, spiders, and extinct relatives widespread
- Actinopterygii — ray-finned fishes in freshwater systems
Archaeo-Dainan（Bōkō, Teishin, Gohyō, Teigō, Zhamo, Heiyū, Boshi, Teigai, Boshu, Shinshin）
Climate: Tropical (south), Temperate (Heiyū, Teigai), Boreal (Zhamo)- Dominant Plant Classes:
- Cycadopsida — abundant in tropical and subtropical lowlands
- Pinopsida — dominant in temperate uplands and boreal reaches
- Polypodiopsida — true ferns widespread across forest floors
- Ginkgoopsida — established in upland temperate forests
- Lycopodiopsida, Equisetopsida — persistent in wetlands and river margins
- Dominant Animal Classes:
- Synapsida — diverse therapsid groups ranging from dicynodonts to early cynodonts
- Reptilia — increasingly agile archosauriforms and small herbivorous reptiles
- Amphibia — large-bodied amphibians still prominent in boreal and tropical wetlands
- Insecta — high diversity, including emerging complete metamorphosis in some groups
- Actinopterygii — freshwater and estuarine systems rich with ray-finned fishes
- Chondrichthyes — coastal sharks and rays present in marine margins
Archaeo-Daisai（Shinshi, Kyōshi, Chishi, Kōbō, Chichū, Tōsai, Shinchū, Shinyū, Shinbō, Konchū, Lomba, Ndali, Chishu）
Climate: Predominantly Tropical, some Subtropical uplands- Dominant Plant Classes:
- Cycadopsida — dominant canopy species across much of the lowlands
- Polypodiopsida — ferns and tree ferns composing the lower canopy and moist forest edges
- Lycopodiopsida — retained in wet equatorial swamps
- Equisetopsida — open floodplain vegetation
- Ginkgoopsida — appearing in drier microclimates
- Pinopsida — early conifers in interior uplands
- Dominant Animal Classes:
- Synapsida — varied therapsids, including large browsers and small insectivores
- Reptilia — growing archosaur presence in uplands and dry basins
- Amphibia — still ecologically dominant near freshwater bodies
- Insecta — insects thriving in tropical forests; high specialization in pollinators, scavengers, and aquatic forms
- Arachnida — diverse and widespread, from primitive spiders to solifuges
- Actinopterygii — fish diversity maintained in freshwater channels and estuaries
Kyougai（Kyougai）
Climate: Tropical- Dominant Plant Classes:
- Cycadopsida — main arboreal flora
- Polypodiopsida — dominant ground and understory plants
- Lycopodiopsida, Equisetopsida — remnant lineages in persistent swamp zones
- Pinopsida — isolated highland stands
- Ginkgoopsida — unique endemic forms likely emerging
- Dominant Animal Classes:
- Synapsida — early endemic cynodont and dicynodont lineages
- Amphibia — retained strong ecological presence across river valleys
- Reptilia — insular radiation of small archosauriforms
- Insecta — highly endemic insect fauna; divergence from continental gene pools underway
- Arachnida — isolated scorpion and spider species evolving in parallel