PLEASE HELP!!!!
1. How many millions of years ago did sharks first appear? (Make sure you are looking for animals that only have cartilage skeletons).
2. How many millions of years ago did bony fish (like the perch) first appear?
3. How many millions of years ago did amphibians first appear?
4. How many millions of years ago did reptiles first appear?
5. How many millions of years ago did modern birds (aves) appear?
6. How many millions of years ago did mammals first appear?
7. How many millions of years ago did humans first appear? (This date will vary depending on the source you pull from but you will at least be in the general proximity).
1. Sharks, which have cartilage skeletons, first appeared approximately 450 million years ago during the Late Ordovician period.
2. Bony fish, such as perches, first appeared around 420 million years ago during the Silurian period.
3. Amphibians first appeared roughly 360 million years ago during the Devonian period.
4. Reptiles first appeared approximately 310 million years ago during the Carboniferous period.
5. Modern birds, known as aves, first appeared around 150 million years ago during the Jurassic period.
6. Mammals first appeared approximately 225 million years ago during the Triassic period.
7. Humans, specifically Homo sapiens, first appeared around 300,000 years ago during the Pleistocene epoch. It is important to note that this date can vary depending on the source and the specific definition of "human" used.
To find the answers to these questions, you can refer to scientific research and paleontological studies. These studies involve dating fossils and analyzing evolutionary patterns. While I can provide estimates based on the current scientific understanding, please note that these dates may vary slightly depending on the sources you consult.
1. Sharks with cartilage skeletons first appeared about 450 million years ago during the Late Ordovician period.
2. Bony fish, like the perch, first appeared approximately 420 million years ago during the Early Silurian period.
3. Amphibians first appeared around 370 million years ago during the Late Devonian period.
4. Reptiles first appeared about 315 million years ago during the Late Carboniferous period.
5. Modern birds (aves) evolved from theropod dinosaurs and first appeared approximately 150 million years ago during the Late Jurassic period.
6. Mammals first appeared around 225 million years ago during the Late Triassic period. However, it is important to note that early mammals were small and inconspicuous compared to dinosaurs during this time.
7. The appearance of modern humans, Homo sapiens, is estimated to have occurred around 200,000 years ago during the Middle to Late Pleistocene epoch. Remember that this date can vary depending on the sources and the specific definition of "human" used.
Remember to consult credible scientific sources to obtain the most accurate information and to stay up to date with any new discoveries or advancements in the field of paleontology.
http://en.wikipedia.org/wiki/Timeline_of_evolutionary_history_of_life
http://www.usefulcharts.com/science/human-evolution-timeline.html