Sharks have been swimming in Earth’s oceans for 400 million years. Trees have only existed for 350 million years. Sharks are older than trees, older than dinosaurs, older than Saturn’s rings. They’re living fossils that have survived five mass extinctions.
—
🦈 Timeline
Sharks: 400 million years ago
Trees: 350 million years ago
Dinosaurs: 230 million years ago
Humans: 300,000 years ago
Sharks predate:
- Trees
- Dinosaurs
- Mammals
- Flowers
- Grass
- Mountains (many current ranges)
—
💡 Why They Survived
Adaptations:
- Cartilage skeleton (lighter, flexible)
- Multiple rows of teeth (replaceable)
- Electroreception (detect prey’s heartbeat)
- Diverse species (500+ types)
- Occupy many niches
Survived:
- Ordovician extinction (444 MYA)
- Devonian extinction (375 MYA)
- Permian extinction (252 MYA) – “Great Dying”
- Triassic extinction (201 MYA)
- Cretaceous extinction (66 MYA) – killed dinosaurs
—
🌟 Modern Threats
Ironically: Survived 400 million years, now threatened by humans
- Overfishing
- Finning
- Habitat loss
- 100 million sharks killed annually
—
Sharks: the ultimate survivors!