Geologic Time and Evolution of Life

Invertebrate An invertebrate is an organism without a backbone Invertebrates of the Cambrian lived only in the oceans Early Paleozoic is known as the age of invertebrates This is a Trilobite. It’s an ocean dweller from the Paleozoic Era.

Fish In the Middle Paleozoic era, vertebrates evolved. Based on your knowledge of “invertebrates”, what is a “vertebrate”? A fish is a limbless cold-blooded vertebrate animal with gills and fins and living wholly in water. This is a Dunkleosteus, a prehistoric fish that was a predator. -What lets you know that it’s a predator?

Amphibian A cold-blooded vertebrate animal of a class that comprises the frogs, toads, newts, and salamanders. They are distinguished by having an aquatic gill-breathing larval stage followed (typically) by a terrestrial lung-breathing adult stage. Can you put that definition in your own words? Use context clues to help with unfamiliar words This is Tiktaalik, one of the earliest amphibians. What kind of organism do you think they resemble?

Vertebrate A vertebrate is an organism with a backbone Can you think of examples?

Coal Swamp A coal swamp is an oxygen-poor environment where, over time, plant material changes into coal. Coal swamps are the major source of coal that we use today A swamp is similar to a lake but it is much shallower. Swamps are covered with water, but this water is shallow enough to allow plants to grow, reaching the surface. Swamps are generally dominated by water tolerant trees.

Supercontinent A supercontinent is an ancient landmass that separated into present-day continents. When our supercontinent formed, it formed closer to the equator causing coal swamps to dry up, and Earth’s climate became cooler and drier. This is Pangaea, the supercontinent. What do you notice about the whole thing?

Mass Extinction The extinction of a large number of species within a relatively short period of geological time, thought to be due to factors such as a catastrophic global event or widespread environmental change that occurs too rapidly for most species to adapt. Fossil evidence indicates that 95% of life-forms in the oceans and 70% of all life on land became extinct. This is known as the Permian mass extinction.

Dinosaur A dinosaur was a dominant Mesozoic land vertebrate that walked with legs positioned directly below its hips. What is a vertebrate? Reptile: A vertebrate animal of a class that includes snakes, lizards, crocodiles, turtles, and tortoises. They are distinguished by having a dry scaly skin and typically laying soft-shelled eggs on land. Compare and contrast between a reptile today and a dinosaur

Pterosaur A Pterosaur (the “p” is silent) is a Mesozoic flying reptile with large, batlike wings Can you think of another flying dinosaur? What do you think is a potential descendant (or ancestor) of these Pterosaurs? This is a Quetzalcoatlus, which is about the size of a giraffe.

Plesiosaur A plesiosaur is a Mesozoic marine reptile with a small head, long neck, and flippers. They dominated the oceans, and were up to about 14 meters (or 45.9 feet long)!

Mammal A mammal is a warm-blooded vertebrate animal of a class that is distinguished by the possession of hair or fur, the secretion of milk by females for the nourishment of the young, and (typically) the birth of live young. Can you give an example of a mammal?

Ice Age A time when a large portion of Earth’s surface is covered by glaciers Only certain organisms could survive during that time. What kind of adaptations do you think they needed?

Mega Mammal A mega mammal is a large mammal of the Cenozoic era