252 — 66 Million Years Ago
Age of Giants
The Complete Dinosaur Chronicle
For 186 million years they ruled every continent, filled every ecological niche, and evolved into creatures so extraordinary that no human imagination could have invented them. This is their story — told the way it deserves to be.
The First Footsteps
After the catastrophic Permian extinction wiped out 96% of all life, the world lay empty. Into this scorched, alien landscape stepped the very first dinosaurs — small, fast, bipedal survivors that would go on to inherit the Earth.
All continents were joined as one supercontinent. Dinosaurs could walk from what is now Argentina to Antarctica without crossing water.
Global temperatures were 6–8°C hotter than today. No polar ice caps. Tropical forests stretched far closer to the poles than anything we’d recognize.
The earliest dinosaurs were dog-sized predators. Their dominance was not yet guaranteed — they competed fiercely with crocodile relatives and therapsids.
Scientists debated for decades whether dinosaurs were fast-blooded, agile animals or slow reptiles. The answer — warm-blooded, energetic, endothermic — rewrote everything we thought we knew.
— Palaeontology’s greatest reversalThe Great Diversification
The Triassic-Jurassic extinction wiped out the dinosaurs’ competitors. Now the world opened up before them. Dinosaurs exploded into every available niche — forests, coasts, riverbanks. Body plans diversified at a staggering rate.
The supercontinent began to rift and separate, creating isolated populations that evolved independently — the engine of enormous dinosaur diversity.
The first truly giant long-necked dinosaurs appear and begin their trend toward enormous size — a trajectory that would produce the largest land animals Earth has ever seen.
Evidence suggests early feather-like structures were appearing by the mid-Jurassic, long before they would become the wings of birds.
Megalosaurus, described in 1824, was the first dinosaur ever scientifically named. Scientists had no idea what they were looking at — they thought it was a giant lizard. It took decades to understand these animals were something entirely new.
— The birth of palaeontologyApproximate relative diversity of known Early Jurassic genera, now vastly expanded through new fossil discoveries.
The Age of Giants
This is the era most people picture when they think “dinosaur.” The Late Jurassic was a world of titans — giant sauropods shaking the earth with each step, armoured stegosaurs browsing fern prairies, and massive predators at the top of every food chain.
Archaeopteryx, 150 million years ago, represents the crucial link between feathered dinosaurs and modern birds. It had feathers, wings, and a wishbone — but also teeth and a bony tail.
Diplodocus stretched 27 metres long. Brachiosaurus stood 13 metres tall at the shoulder. These animals required extraordinary biological systems just to exist.
A geological goldmine in the American West, this Late Jurassic layer has yielded more iconic dinosaur fossils than almost any other formation on Earth.
A Diplodocus heart would have needed to pump blood over 8 metres upward to reach its brain. Scientists still debate how sauropods managed their circulation — some suggest multiple hearts, others propose unique vascular anatomy.
— The sauropod paradoxA World Transformed
Continents drift further apart. Flowering plants appear for the first time, beginning to reshape every ecosystem. A new wave of bizarre, specialised dinosaurs emerges — from sail-backed river hunters to dinosaurs with elaborate crests, spines, and horns.
At up to 15 metres, Spinosaurus was possibly the largest predatory dinosaur ever. Recent discoveries show it was semi-aquatic, hunting fish like a colossal heron.
The rise of angiosperms (flowering plants) co-evolved with insects, created new food sources, and fundamentally altered herbivore behaviour and distribution.
China’s Liaoning formation reveals an astounding diversity of feathered dinosaurs — many colourful, some capable of gliding, all pointing to birds as living dinosaurs.
Microraptor, discovered in 2000, had four wings — one pair on its arms and one on its legs. It could glide, possibly even achieve powered flight. It forces us to rethink the entire evolution of bird flight.
— China’s feathered revolution
The Last Dynasty
The final chapter of the non-avian dinosaurs produced their most extraordinary cast. T-Rex, Triceratops, Ankylosaurus, the hadrosaurs — these are the icons of popular imagination, and they were every bit as remarkable in reality.
Tyrannosaurus rex had a bite force of 8,000 pounds per square inch — enough to crush bone and extract marrow. Its brain was large, senses acute. It was almost certainly feathered in its youth.
The last sauropods became the largest land animals to ever live. Argentinosaurus may have reached 80–100 tonnes — the equivalent of 15 elephants.
The real Velociraptor was turkey-sized, covered in feathers, and hunted small prey. The version in Jurassic Park was actually based on Deinonychus — and was still three times too large.
We now know T-Rex grew at a rate of 2.07 kilograms per day during its teenage years — the fastest growth rate of any known dinosaur. A 20-year-old T-Rex had already reached near-full size and was hunting the largest prey on land.
— The T-Rex growth mystery, solvedVisual Infographic
How Big Were They, Really?
Relative height comparison · hover each bar to explore
66 Million Years Ago · The K-Pg Boundary
The End of Everything
Chicxulub. 10 kilometres. 72,000 mph.
An asteroid roughly the size of Mount Everest struck what is now the Yucatán Peninsula with the force of a billion nuclear bombs. The impact triggered earthquakes, tsunamis, wildfires, and an impact winter that blocked sunlight for years. The non-avian dinosaurs — every last species — were gone within thousands of years.
But Wait — Dinosaurs Never Truly Died
The birds that survived that impact are avian dinosaurs. Every sparrow, eagle, and penguin alive today is a living dinosaur. When scientists say “non-avian dinosaurs went extinct,” they mean the 999 out of 1,000 lineages that didn’t make it. The one that did produced over 10,000 species alive today — more than all mammals combined.
Classification
The Dinosaur Family Tree
Dinosaurs split into two great lineages early in the Triassic — and that division shaped 186 million years of evolution
Includes ALL predatory dinosaurs and the giant long-necked sauropods. Confusingly, this group also gave rise to birds.
All the armoured, horned, crested, and plated dinosaurs. Despite their “bird hip,” no birds evolved from this group.
Bipedal carnivores (and some herbivores). This lineage never stopped evolving — it became birds.
The largest land animals ever. Evolved from small bipedal ancestors into 100-tonne titans over 80 million years of gradual scaling.
Surprising Facts
Things That Will Rewire Your Brain
They Were Warm-Blooded
Modern analysis of growth rings in dinosaur bones confirms most were warm-blooded endotherms — more like mammals and birds than the slow cold-blooded lizards once imagined.
Many Were Colourful
Analysis of melanosomes (pigment cells) preserved in fossils reveals dinosaurs had vivid plumage — iridescent blacks, rich reds, and complex patterns. Think peacocks, not grey lizards.
They May Have Hummed
Hadrosaur crests like Parasaurolophus’s were likely resonating chambers. Computer models suggest they produced low, haunting calls — not roars. The Jurassic may have been surprisingly musical.
Parental Care Was Common
Fossil nesting sites show many dinosaurs sat on eggs and cared for their young — Maiasaura (“good mother lizard”) was named for the evidence of its nurturing behaviour.
T-Rex Was Almost Blind in One Eye
T-Rex had forward-facing eyes giving it stereoscopic vision — but its brain’s olfactory bulbs were enormous. It likely hunted more by smell than sight, like a super-predatory bloodhound.
New Species Found Every 2 Weeks
Palaeontologists currently name a new dinosaur species roughly every two weeks. We’ve named around 1,000 species but estimate 700–1,700 more remain buried, undiscovered.
Keep Exploring
Down the Rabbit Hole
The Mesozoic Era is just the beginning
252 — 66 Million Years Ago
Age of Giants
The Complete Dinosaur Chronicle
For 186 million years they ruled every continent, filled every ecological niche, and evolved into creatures so extraordinary that no human imagination could have invented them. This is their story — told the way it deserves to be.
The First Footsteps
After the catastrophic Permian extinction wiped out 96% of all life, the world lay empty. Into this scorched, alien landscape stepped the very first dinosaurs — small, fast, bipedal survivors that would go on to inherit the Earth.
All continents were joined as one supercontinent. Dinosaurs could walk from what is now Argentina to Antarctica without crossing water.
Global temperatures were 6–8°C hotter than today. No polar ice caps. Tropical forests stretched far closer to the poles than anything we’d recognize.
The earliest dinosaurs were dog-sized predators. Their dominance was not yet guaranteed — they competed fiercely with crocodile relatives and therapsids.
Scientists debated for decades whether dinosaurs were fast-blooded, agile animals or slow reptiles. The answer — warm-blooded, energetic, endothermic — rewrote everything we thought we knew.
— Palaeontology’s greatest reversalThe Great Diversification
The Triassic-Jurassic extinction wiped out the dinosaurs’ competitors. Now the world opened up before them. Dinosaurs exploded into every available niche — forests, coasts, riverbanks. Body plans diversified at a staggering rate.
The supercontinent began to rift and separate, creating isolated populations that evolved independently — the engine of enormous dinosaur diversity.
The first truly giant long-necked dinosaurs appear and begin their trend toward enormous size — a trajectory that would produce the largest land animals Earth has ever seen.
Evidence suggests early feather-like structures were appearing by the mid-Jurassic, long before they would become the wings of birds.
Megalosaurus, described in 1824, was the first dinosaur ever scientifically named. Scientists had no idea what they were looking at — they thought it was a giant lizard. It took decades to understand these animals were something entirely new.
— The birth of palaeontologyApproximate relative diversity of known Early Jurassic genera, now vastly expanded through new fossil discoveries.
The Age of Giants
This is the era most people picture when they think “dinosaur.” The Late Jurassic was a world of titans — giant sauropods shaking the earth with each step, armoured stegosaurs browsing fern prairies, and massive predators at the top of every food chain.
Archaeopteryx, 150 million years ago, represents the crucial link between feathered dinosaurs and modern birds. It had feathers, wings, and a wishbone — but also teeth and a bony tail.
Diplodocus stretched 27 metres long. Brachiosaurus stood 13 metres tall at the shoulder. These animals required extraordinary biological systems just to exist.
A geological goldmine in the American West, this Late Jurassic layer has yielded more iconic dinosaur fossils than almost any other formation on Earth.
A Diplodocus heart would have needed to pump blood over 8 metres upward to reach its brain. Scientists still debate how sauropods managed their circulation — some suggest multiple hearts, others propose unique vascular anatomy.
— The sauropod paradoxA World Transformed
Continents drift further apart. Flowering plants appear for the first time, beginning to reshape every ecosystem. A new wave of bizarre, specialised dinosaurs emerges — from sail-backed river hunters to dinosaurs with elaborate crests, spines, and horns.
At up to 15 metres, Spinosaurus was possibly the largest predatory dinosaur ever. Recent discoveries show it was semi-aquatic, hunting fish like a colossal heron.
The rise of angiosperms (flowering plants) co-evolved with insects, created new food sources, and fundamentally altered herbivore behaviour and distribution.
China’s Liaoning formation reveals an astounding diversity of feathered dinosaurs — many colourful, some capable of gliding, all pointing to birds as living dinosaurs.
Microraptor, discovered in 2000, had four wings — one pair on its arms and one on its legs. It could glide, possibly even achieve powered flight. It forces us to rethink the entire evolution of bird flight.
— China’s feathered revolutionThe Last Dynasty
The final chapter of the non-avian dinosaurs produced their most extraordinary cast. T-Rex, Triceratops, Ankylosaurus, the hadrosaurs — these are the icons of popular imagination, and they were every bit as remarkable in reality.
Tyrannosaurus rex had a bite force of 8,000 pounds per square inch — enough to crush bone and extract marrow. Its brain was large, senses acute. It was almost certainly feathered in its youth.
The last sauropods became the largest land animals to ever live. Argentinosaurus may have reached 80–100 tonnes — the equivalent of 15 elephants.
The real Velociraptor was turkey-sized, covered in feathers, and hunted small prey. The version in Jurassic Park was actually based on Deinonychus — and was still three times too large.
We now know T-Rex grew at a rate of 2.07 kilograms per day during its teenage years — the fastest growth rate of any known dinosaur. A 20-year-old T-Rex had already reached near-full size and was hunting the largest prey on land.
— The T-Rex growth mystery, solvedVisual Infographic
How Big Were They, Really?
Relative height comparison · hover each bar to explore
66 Million Years Ago · The K-Pg Boundary
The End of Everything
Chicxulub. 10 kilometres. 72,000 mph.
An asteroid roughly the size of Mount Everest struck what is now the Yucatán Peninsula with the force of a billion nuclear bombs. The impact triggered earthquakes, tsunamis, wildfires, and an impact winter that blocked sunlight for years. The non-avian dinosaurs — every last species — were gone within thousands of years.
But Wait — Dinosaurs Never Truly Died
The birds that survived that impact are avian dinosaurs. Every sparrow, eagle, and penguin alive today is a living dinosaur. When scientists say “non-avian dinosaurs went extinct,” they mean the 999 out of 1,000 lineages that didn’t make it. The one that did produced over 10,000 species alive today — more than all mammals combined.
Classification
The Dinosaur Family Tree
Dinosaurs split into two great lineages early in the Triassic — and that division shaped 186 million years of evolution
Includes ALL predatory dinosaurs and the giant long-necked sauropods. Confusingly, this group also gave rise to birds.
All the armoured, horned, crested, and plated dinosaurs. Despite their “bird hip,” no birds evolved from this group.
Bipedal carnivores (and some herbivores). This lineage never stopped evolving — it became birds.
The largest land animals ever. Evolved from small bipedal ancestors into 100-tonne titans over 80 million years of gradual scaling.
Surprising Facts
Things That Will Rewire Your Brain
They Were Warm-Blooded
Modern analysis of growth rings in dinosaur bones confirms most were warm-blooded endotherms — more like mammals and birds than the slow cold-blooded lizards once imagined.
Many Were Colourful
Analysis of melanosomes (pigment cells) preserved in fossils reveals dinosaurs had vivid plumage — iridescent blacks, rich reds, and complex patterns. Think peacocks, not grey lizards.
They May Have Hummed
Hadrosaur crests like Parasaurolophus’s were likely resonating chambers. Computer models suggest they produced low, haunting calls — not roars. The Jurassic may have been surprisingly musical.
Parental Care Was Common
Fossil nesting sites show many dinosaurs sat on eggs and cared for their young — Maiasaura (“good mother lizard”) was named for the evidence of its nurturing behaviour.
T-Rex Was Almost Blind in One Eye
T-Rex had forward-facing eyes giving it stereoscopic vision — but its brain’s olfactory bulbs were enormous. It likely hunted more by smell than sight, like a super-predatory bloodhound.
New Species Found Every 2 Weeks
Palaeontologists currently name a new dinosaur species roughly every two weeks. We’ve named around 1,000 species but estimate 700–1,700 more remain buried, undiscovered.
Keep Exploring
Down the Rabbit Hole
The Mesozoic Era is just the beginning