these are all very confusing for me
1. Explain why Earth and other planets were not solid when they formed during the beginning of the Precambrian, approximately 4,600 million years ago (MYA). What was this particular time period called, and why is this time period not really considered a part of Earth’s geological history?
2. Describe the two most important events in the history of animal life that occurred at the beginning and at the end of the Paleozoic era. (2 pts) List and briefly outline the six different periods into which the Paleozoic era is divided. (6 pts)
3. Describe how the Triassic period was a transitional time period during the Mesozoic era. Explain why the boundary between the Triassic and Jurassic periods is similar to the boundary between the Permian and Triassic periods.
4. Recall from previous activities in this lesson which era is sometimes referred to as the Age of Mammals. Locate and click on this section of the geologic time scale, and list the other possible names that could have been used to describe this era, and why.
i need help!
I need help on that too so :( HEEEEELP!!!!!!!!
Cenozoic could have been called the "Age of Flowering Plants" or the "Age of Insects" or the "Age of Teleost Fish" or the "Age of Birds" just as accurately.
Found it at: ucmp.berkeley.edu/cenozoic/cenozoic
At the end of the first paragraph.
Go on the connexus education website, you can find it there :)
1. The Earth and other planets were not solid when they formed during the beginning of the Precambrian era because they were undergoing a process called accretion. Accretion is the gradual accumulation of matter through collisions and gravitational attraction. As the early Solar System formed from a rotating disk of gas and dust, particles collided and stuck together, forming larger and larger objects. Over time, these objects called planetesimals grew into protoplanets, and eventually, the Earth and other planets. During this process, the materials were heated and melted, resulting in a partially molten state.
The particular time period when the Earth and other planets were forming is known as the Hadean Eon, which lasted from about 4.6 to 4 billion years ago. The name "Hadean" comes from the Greek god Hades, representing the fiery and turbulent conditions prevalent during this time. It is not considered a part of Earth's geological history because there are very few rock formations or other geological evidence left from that time. The intense geological activity, such as volcanic activity and heavy bombardment from comets and asteroids, erased most traces of the Hadean Eon. Therefore, the geological history of the Earth is generally considered to begin with the rocks and evidence from the subsequent eon, the Archean.
2. The two most important events in the history of animal life at the beginning and end of the Paleozoic era are the Cambrian Explosion and the Permian-Triassic Extinction event.
The Cambrian Explosion, which occurred approximately 541 million years ago, marks a significant period of rapid diversification and evolution of multicellular animals. It is considered the event that led to the emergence of a wide variety of complex body plans and the first appearance of most major animal groups.
The Permian-Triassic Extinction event, which happened around 252 million years ago, is the most severe mass extinction event in Earth's history. It resulted in the loss of up to 96% of marine species and 70% of terrestrial vertebrate species. This event had a profound impact on the evolution of life on Earth, opening up opportunities for new species to evolve and dominate in the post-extinction world.
The Paleozoic era is divided into six different periods, each with its own characteristics and significant events:
1. Cambrian Period: This period witnessed the Cambrian Explosion and the proliferation of diverse marine life forms, including the first evidence of hard-shelled organisms.
2. Ordovician Period: During this period, the colonization of land by plants and animals began, and marine life continued to diversify.
3. Silurian Period: The first terrestrial ecosystems with plants, insects, and early arthropods evolved during this period. Fish also became more dominant in the seas.
4. Devonian Period: Often referred to as the "Age of Fishes," this period saw the diversification of fish species and the emergence of the first tetrapods (early land-dwelling vertebrates).
5. Carboniferous Period: Known for its extensive swamp forests and the formation of vast coal deposits. Amphibians were the dominant land vertebrates, and early reptiles began to evolve.
6. Permian Period: This period saw the emergence of reptiles as the dominant land animals and the origin of mammal-like reptiles (therapsids). It ended with the Permian-Triassic Extinction event.
3. The Triassic period is considered a transitional time period during the Mesozoic era because it bridges the gap between the Permian period, which ended with a mass extinction event, and the Jurassic period, which saw the rise of dominant dinosaurs. During the Triassic period, ecosystems and species diversified, recovering from the Permian extinction.
The boundary between the Triassic and Jurassic periods is similar to the boundary between the Permian and Triassic periods because they both mark significant extinction events. The boundary between the Permian and Triassic, known as the Permian-Triassic Extinction event, was the most severe mass extinction event in Earth's history. Similarly, the boundary between the Triassic and Jurassic, known as the Triassic-Jurassic Extinction event, marked another significant extinction event, although less severe than the Permian-Triassic extinction. Both events caused major shifts in ecosystems and paved the way for the rise of new groups of organisms in the subsequent time period.
4. The era that is sometimes referred to as the "Age of Mammals" is the Cenozoic era. This era began around 65 million years ago and continues to the present day. The Cenozoic era is characterized by the diversification and dominance of mammals on Earth.
Other possible names for the Cenozoic era include:
- The Age of Mammals: This name highlights the prominence and success of mammals during this era.
- The Age of Humans: It is also referred to as the Age of Humans because Homo sapiens, or modern humans, appeared during this era and have had a significant impact on the planet's ecosystems.
- The Age of Flowering Plants: The rise and diversification of flowering plants, or angiosperms, occurred during the Cenozoic era, shaping the terrestrial ecosystems.
- The Age of Ice: The Cenozoic era has seen multiple ice ages and glaciations, including the current Ice Age that began around 2.6 million years ago and shaped the global climate and geography.
These names highlight different aspects and significant events that characterize the Cenozoic era.