Salt glands, not swimming: Why dinosaurs never conquered the oceans

For 150 million years, dinosaurs commanded the land with unrivaled authority, yet the ocean — teeming with reptilian giants — remained forever beyond their reach. A study published in Historical Biology now suggests the barrier was not one of limb or lung, but of chemistry: most dinosaurs appear to have lacked the salt-excreting glands above the eyes that allow modern seabirds to drink from the sea and survive. Only the spinosaurs, those elongated, fish-hunting wanderers of rivers and deltas, show fossil evidence of developing this quiet physiological key — a door they approached but never ful