HEADLINE: Greenhouse Antarctica, the First Whales, and the Survival Strategies Post-Asteroid Impact BOOK TITLE: Other Lands, a journey through Earth's extinct world GUEST AUTHOR NAME: Thomas Halliday 200-WORD SUMMARY: This section begins in the Eocene (41

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HEADLINE: Greenhouse Antarctica, the First Whales, and the Survival Strategies Post-Asteroid Impact
BOOK TITLE: Other Lands, a journey through Earth's extinct world

GUEST AUTHOR NAME: Thomas Halliday
200-WORD SUMMARY: This section begins in the Eocene (41 million years ago), a time of Greenhouse Earthcharacterized by no permanent polar ice, high CO2 (800 ppm), and temperatures about five degrees Celsius warmer than today. Seymour Island (West Antarctic Peninsula) hosted a diverse temperate rainforest before the onset of glaciation. The cooling process was triggered by the opening of the Drake Passage, which created the circum-polar current and isolated Antarctica from tropical warmth. Marine life included Pelagornis, a pseudo-toothed bird analogous to the albatross, and Basilosaurus, the first truly aquatic whale, which evolved from coastal predators. Despite the warmth, the Antarctic region still endured three months of total darkness in winter, requiring plants to drop their leaves. The conversation then shifts to the Paleocene following the K-Pg mass extinction. This extinction was caused by an exogenous asteroid strike in the Yucatan Peninsula, which halted photosynthesis worldwide for years due to atmospheric soot. Most animals larger than a small dog perished. The rapid diversification of mammals, specifically Eutherians (placental mammals), began immediately after the extinction event. Survival was facilitated by being small, insectivorous, and burrowing, which provided a stable environment against extreme temperature swings.