Ancient Civilizations & Origins · Deep Time
Twenty-six chapters, one continuous record
The deep-time index: 26 chapters from the formation of Earth to the end of antiquity, each one rated by how much of the record survives.
- Chapters
- 26
- Eras
- 6
- Span
- 4.54 Bya – 1500 CE
How strong the record is across this collection
- 12 Documented Historical Record
- 6 Archaeological Evidence
- 5 Scientific Consensus
- 3 Active Academic Debate
Older chapters lean on geology and genetics; later ones on excavation and written record. The badge tells you which you are reading.
Attested in primary written sources that historians treat as reliable for this claim.
Supported by excavated material: stratigraphy, artifacts, dating, or site survey.
The mainstream position across the relevant scientific literature today.
Specialists disagree. Competing interpretations are presented side by side.
Second City Standard's own reading of the evidence, labeled as such.
Proposed but unsupported by accepted evidence. Reported, never endorsed.
Scroll horizontally · 26 periods, Earth formation to the Middle Ages.
4.54 billion years ago
Earth Formation
Accretion of the planet and the isotopic dating methods that fix its age.
3.7 billion – 541 million years ago
Early Life
Stromatolites, the oxygenation of the atmosphere, and the first multicellular life.
233 – 66 million years ago
Dinosaurs
The Mesozoic record and the impact evidence for the end-Cretaceous extinction.
2.6 million – 11,700 years ago
Ice Ages
Glacial cycles, sea-level change, and the landscapes early humans actually walked.
4.2 – 2 million years ago
Australopithecus
Bipedalism before big brains — Lucy, Laetoli, and what the fossils can support.
2.3 – 1.5 million years ago
Homo Habilis
The first toolmakers, and the ongoing argument about where the genus Homo begins.
1.9 million – 110,000 years ago
Homo Erectus
The first long-distance migrants — fire, hand axes, and a two-million-year run.
400,000 – 40,000 years ago
Neanderthals
Burial, pigment, and the genomic evidence for interbreeding with modern humans.
300,000 – 30,000 years ago
Denisovans
A population defined largely by DNA — and what a finger bone can and cannot tell us.
4500 – 1900 BCE
Sumer
Cities, cuneiform, and the earliest written administration on record.
3100 – 30 BCE
Egypt
Three thousand years of continuous state records, monuments, and engineering.
1894 – 539 BCE
Babylon
Law codes, astronomy tablets, and the mathematics of a base-60 world.
2025 – 609 BCE
Assyria
Empire logistics, siege warfare, and the library that preserved Mesopotamian literature.
550 – 330 BCE
Persia
The Achaemenid administrative machine and the roads that held it together.
1200 – 586 BCE
Israel
Where text and excavation agree, where they diverge, and how the debate is argued.
1500 – 300 BCE
Phoenicia
Maritime trade networks and the alphabet that traveled with them.
3300 – 1300 BCE
Indus Valley
Urban planning at scale — and a script still undeciphered.
1600 BCE – 220 CE
Ancient China
Oracle bones, bronze metallurgy, and the long dynastic record.
800 – 146 BCE
Greece
City-states, natural philosophy, and the first surviving works of history.
753 BCE – 476 CE
Rome
Engineering, law, and the administrative record of a Mediterranean empire.
2000 BCE – 1500 CE
Maya
A fully deciphered script, precise astronomy, and a still-contested collapse.
1300 – 1521 CE
Aztec
Lake-city agriculture, tribute economics, and codices written on both sides of conquest.
1438 – 1533 CE
Inca
Road systems, khipu record-keeping, and stonework still being reverse-engineered.
476 – 1500 CE
Middle Ages
What survived antiquity, what was copied, and what was lost in transmission.