Earth Systems · Deep Time · Extinction

The K-Pg Extinction

The asteroid was real, but the extinction was not a one-frame explosion. Students trace how impact energy, blocked sunlight, volcanic stress, ocean chemistry, and food webs turned one event into a months-to-years ecological collapse.

66 million years ago Non-avian dinosaurs Impact winter Marine plankton Survivor niches

Misconceptions to Retire

Not Instant Death

The impact caused immediate regional catastrophe, but mass extinction followed through darkness, cooling, starvation, and ecological failure.

Birds Are Dinosaurs

The better phrase is non-avian dinosaurs. One theropod lineage survived and diversified into modern birds.

Not Asteroid-Only

Deccan Traps volcanism had already stressed climate and chemistry. The impact likely landed on an unstable system.

Oceans Count

Plankton and foraminifera losses damaged marine food webs from the microscopic base upward.

Niche Beat Size

Small non-avian dinosaurs still vanished, while some larger turtles and crocodilians survived through metabolism, habitat, and flexible diets.

Numbers Tell Systems

Dates, durations, percentages, body size, and population recovery rates help students see history as connected change.

Layered Timeline

Before 66 Ma
Environmental stress buildsDeccan eruptions release carbon dioxide and sulfur compounds, shifting climate before impact day.
Impact day
Chicxulub hitsShock waves, tsunamis, ejecta, heat pulses, and fires create immediate devastation.
Weeks-months
Sunlight is blockedDust, soot, and sulfur aerosols reduce photosynthesis and cool the surface.
Months-years
Food webs collapsePlants and plankton decline first, then herbivores, predators, and marine reptiles lose their energy base.
Afterward
Survivors inherit the recoveryBirds, mammals, crocodilians, turtles, insects, seeds, spores, and deep-water food chains shape the next world.

3D Extinction Gallery

Tyrannosaurus rex

A large non-avian theropod predator. Use it to ask why apex predators are vulnerable when herbivore prey disappears. Source

Triceratops

A late Cretaceous herbivore. Connect its survival problem to photosynthesis, plant die-off, and calorie demand. Source

Mosasaurus

A marine reptile, not a dinosaur. Its extinction keeps ocean chemistry and plankton collapse in the story. Source

Pteranodon

A pterosaur, not a dinosaur. It helps separate clades from the broad popular label "prehistoric animals." Source

Ankylosaurus

An armored herbivore from the late Cretaceous. Armor did not solve a collapsing food system. Source

Ammonite

A marine cephalopod group that vanished at the boundary. A compact doorway into ocean food webs and index fossils. Source

Misconception vs Evidence

Misconception	Better framing
Instant explosion	The impact started a cascade. The mass extinction played out through climate, photosynthesis, and food webs.
All dinosaurs died	Non-avian dinosaurs died out. Avian dinosaurs survived as birds.
Fire killed everything	Fire, tsunamis, and heat mattered, but darkness, cooling, acidification, and starvation carried the global damage.
Mammals were smarter	Survival favored niches: small bodies, burrowing, scavenging, flexible diets, seeds, dormancy, and lower energy needs.

Classroom Prompt

Story of Numbers extension: Build a timeline where each number has a job. Which numbers show scale, which show duration, which show survival, and which reveal that tiny organisms can decide the fate of giant animals?