白垩纪 (Bái è jì) — Cretaceous period (geological period, approx. 145–66 million years ago)

Definition

Examples

• 恐龙在白垩纪末期灭绝了。
  Kǒng lóng zài Bái è jì mò qī miè jué le.
  Dinosaurs went extinct at the end of the Cretaceous period.
• 白垩纪的地层中含有大量石灰岩。
  Bái è jì De dì céng zhōng hán yǒu dà liàng shí huī yán.
  The strata of the Cretaceous period contain large amounts of limestone.
• 科学家在白垩纪岩石中发现了新的化石。
  Kē xué jiā zài Bái è jì yán shí zhōng fā xiàn le xīn de huà shí.
  Scientists discovered new fossils in Cretaceous rocks.