Abstract
Imagine the seas off Peru, 6 million years ago. A group of long-nosed dolphins swam through the warm seawater, breaking the surface with occasional enthusiastic leaps into the stark sunshine, then diving crisply back into the clear water to join their compadres.
Not far away, a pod of small baleen whales headed southward to feed in the nutrient-rich Antarctic waters. Three males and four females were clustered together in a rather tight formation as they swam along at their regular pace, always wary of imminent danger.
About 6 million years ago, the seas off Peru were much warmer than today, by at least 4°C. The middle part of the Miocene period (23–5.3 million years ago) had been a warm time throughout the world, with sea temperatures soaring to 31°C in places. That was a time of great expansion of whales and other marine life as productivity soared in the oceans.
In the final million years of the period, two of the three marine gateways connecting the warmer tropical seas together had closed, blocked by tectonic uplifts. This caused a dramatic rerouting of oceanic currents, resulting in abrupt cooling of the oceans. Food resources were on the wane, so predators had to hunt harder for food.
Gigantic predators had an even harder time, as they needed much more food each day than smaller creatures...
Not far away, a pod of small baleen whales headed southward to feed in the nutrient-rich Antarctic waters. Three males and four females were clustered together in a rather tight formation as they swam along at their regular pace, always wary of imminent danger.
About 6 million years ago, the seas off Peru were much warmer than today, by at least 4°C. The middle part of the Miocene period (23–5.3 million years ago) had been a warm time throughout the world, with sea temperatures soaring to 31°C in places. That was a time of great expansion of whales and other marine life as productivity soared in the oceans.
In the final million years of the period, two of the three marine gateways connecting the warmer tropical seas together had closed, blocked by tectonic uplifts. This caused a dramatic rerouting of oceanic currents, resulting in abrupt cooling of the oceans. Food resources were on the wane, so predators had to hunt harder for food.
Gigantic predators had an even harder time, as they needed much more food each day than smaller creatures...
| Original language | English |
|---|---|
| Specialist publication | The Conversation |
| Publisher | The Conversation (Aust.) |
| Publication status | Published - 13 Sept 2024 |
Keywords
- palaeontology
- megalodon
- book
- Secret History of Sharks