Alsea Formation facts for kids

Quick facts for kids Alsea Formation Stratigraphic range: Rupelian (Whitneyan) ~33.7–30.6Ma PreЄ Є O S D C P T J K Pg N ↓
Type	Formation
Underlies	Yaquina Formation
Lithology
Primary	Siltstone
Other	Mudstone
Location
Coordinates	44°36′N 124°00′W / 44.6°N 124.0°W / 44.6; -124.0
Approximate paleocoordinates	44°18′N 113°06′W / 44.3°N 113.1°W / 44.3; -113.1
Region	Lincoln County, Oregon
Country	United States

The Alsea Formation is a special set of rock layers found in Oregon. These rocks hold amazing clues about life from a very long time ago.

Scientists study the Alsea Formation to find fossils. These fossils are like natural time capsules. They show us what animals and plants lived here during the Rupelian stage of the Oligocene period. That was about 33.7 to 30.6 million years ago!

What Ancient Life Lived Here?

The Alsea Formation is famous for the ancient animal remains found within its rocks. These fossils help us understand Earth's history.

Ancient Mammals

Some very old mammal fossils have been discovered in the Alsea Formation. These include:

• Aetiocetus cotylalveus: This was an early type of whale.
• Maiabalaena nesbittae: Another ancient whale species.
• Simocetus rayi: This was also a kind of early whale.

Ancient Fish

Fossils of fish have also been found, telling us about the ancient oceans. One important fish fossil is:

• Orthechinorhinus davidae: This was a type of ancient shark.