Lecture on 150 Million Years Ago During the Late Jurassic

Introduction

• Mad scientist scenario: Traveling back 150 million years is dangerous
• Dinosaurs ruled the land
• Land, ocean, and skies were unfriendly to life
• Welcome to the Late Jurassic

Geography

• Landmasses:
  • North America: Most recognizable but still different
  • Gondwana: Supercontinent composed of South America, Arabian Peninsula, India, Antarctica, and Australia
  • Laasia: Present-day Europe, Greenland, parts of Asia, covered by waters and split into islands
• Oceans:
  • Pacific Ocean: Covered Western Hemisphere
  • Tethys Ocean: Covered Eastern Hemisphere, higher sea levels
  • Atlantic Ocean: Resembled a sea, warmer temperatures

Climate

• Higher average temperatures: 32.1°C (90°F)
• Increased tectonic activity and volcanoes
• TAMU Massif: Earth's largest known volcano, off east coast of Japan
• Warmer oceans: Even deep oceans were warmer
• Diverse biomes:
  • Deserts and savannas near equator
  • Temperate polar regions without ice sheets
  • Tropical forests in North Africa

Fauna

• Dinosaurs: Golden Age of diversification
  • Theropods:
    • Allosaurus: Dominant predator, lion of Jurassic
    • Saurophaganax: Biggest predator, 5 tons
    • Torvosaurus and Edmarka rex: Megalosaurids, also massive
    • Ceratosaurus: Smaller but agile, deadly bite
    • Smaller therapods: Troodonts
  • Herbivores:
    • Dryosaurus and Camptosaurus: Fast but defenseless
    • Stegosaurus: Large, with thagomizers
    • Mygurasaurus: Early ankylosaur
• Crocodiloforms: Dominated waters, semi-aquatic and terrestrial
• Mammaliaforms: Early ancestors, small but adaptable
• Pterosaurs: Dominant flyers, successful but rare remains
  • Lucius: Largest pterosaur, 3.6m wingspan
• Bird-like Dinosaurs: Archaeopteryx, earliest known capable of powered flight

Marine Life

• Plesiosaurs: Global presence, apex predators
  • Pliosaurs: Short necks, massive skulls, e.g., Pliosaurus
  • Icthyosaurs: Still prevalent but smaller than Triassic ancestors
• Thalattosuchians: Marine crocodiles, global hunters
• Sharks: Smaller but significant predators, e.g., Dakosaurus and Machimosaurus

Key Takeaways

• Late Jurassic was a dangerous and diverse period
• High average temperatures and large volcanic activity
• Diverse ecosystems with extreme climates
• Wide variety of terrifying predators on land and in the water

Conclusion: Avoid traveling to 150 million years ago due to significant dangers from diverse and massive predators and harsh climates