One of the displays in Montana Natural History Center’s Museum in Missoula explains the ancient past—i.e. the paleontology—of the state.
According to the Montana Natural History Center:
“Step back in time to prehistoric Montana! You might find yourself floating in a shallow sea, sloshing through a murky swamp, or sliding around on vast sheets of ice. Montana’s rich fossil record represents nearly every major time period in Earth’s history. Take a journey through geologic time and discover how fossils tell the story of Montana’s ancient past—and paint a picture of the future.”
According to the Montana Natural History Center:
“The earth is 4.5 billion years old, and throughout its history dramatic changes in geology and climate have significantly influenced the evolution of life. At times these changes caused the diversity, or variety, of plant and animal life to explode. Other times they triggered massive extinction events that caused many plants and animals to completely disappear.”
Precambrian
The Precambrian makes up most—90%--of the history of our planet. It is defined by the formation of an ocean and the evolution of bacteria and algae.
According to the Montana Natural History Center:
“Billions of years ago in what is now Montana, a warm, shallow sea covered the land. The climate was hot and humid, and suffocating levels of carbon dioxide filled the atmosphere.”
Cyanobacteria—single-celled organisms—evolved in the ocean toward the end of the Precambrian. They used photosynthesis to convert sunlight, water, and carbon dioxide into food. During this process, they also produced oxygen and more oxygen in the atmosphere set the stage for the evolution of plants and animals such as seaweeds, worms, and sponges.
Paleozoic
In the Paleozoic, simple life-forms diversified and began the long evolution into today’s plants and animals. According to the Montana Natural History Center:
“In the early Paleozoic, Montana lay flat beneath a shallow sea teeming with trilobites, algae, and coral. The climate then cooled significantly, causing an ice age that forced the sea to retreat as the water froze into glaciers. When the climate warmed again the glaciers melted and the sea returned to Montana, bringing sponges, mollusks, and boneless fishes with it.”
Bear Gulch Limestone
Covering 25 square miles, Bear Gulch near Lewistown, Montana is known for well-preserved fossils. According to the Montana Natural History Center:
“The Bear Gulch fossils have revealed incredible details of the life, habitats, and ecosystems that existed over 300 million years ago.”
More Paleontology
Paleontology 101: Montana's Ancient Past (museum tour)
Paleontology 101: The Precambrian--Life Begins (Photo Diary)
Paleontology 101: The Paleozoic (Photo Diary)
Paleontology 101: The Cenozoic--The Age of Mammals (Photo Diary)
Paleontology 101: The Mesozoic--The Age of Dinosaurs (Photo Diary)
Paleontology 101: The California Pleistocene (Photo Diary)
Paleontology 101: The Fossil Gallery in the Rice Museum (Photo Diary)
Paleontology 101: Ammonites and Crinoids (Photo Diary)