Nocturnal bottleneck

High school (ages 12+)
Animals & Nature

Name:

Date:

Step 1 · Read the article

Open the article and read it at the level above. Then answer the questions below in your own words.

https://smallwhale.org/articles/nocturnal-bottleneck

Write what each word means, using the article.

Do not copy the article. Write two things you learned, the way you would explain them to a friend.

Answers below are taken from the article’s stored facts, so they match what the student read.

1. How big is Nocturnal bottleneck?Approximately 160 million years, from the Late Triassic to post-Cretaceous–Paleogene extinction
2. What is the primary evolutionary driver?Ecological dominance of dinosaurs, forcing early mammals into nocturnal niches for survival
3. What is the nocturnal bottleneck hypothesis?It says that for a very long time, most mammals were active at night, which shaped how they look and work.
4. Why did early mammals live at night?Dinosaurs took most daytime spots, so early mammals stayed in the dark to avoid big predators and find food safely.

Nocturnal Bottleneck Hypothesis: An evolutionary theory proposing that mammals evolved for a long period primarily as nocturnal creatures.
Cretaceous–Paleogene Extinction Event: The mass extinction event approximately 66 million years ago that wiped out non-avian dinosaurs.
Diurnal Niches: Ecological roles and habitats primarily occupied and utilized during daylight hours.