Paleontological evidence (evidence from fossils) shows that evolution has occurred. By the study of fossils, it is known that 570 million years ago, there was not suitable condition for living organisms on the land to evolve but some single-celled organisms were originated in oceans.
The oldest plant was originated about 320 million years ago and the invertebrate animals were originated about 120 million years ago. But the first organism was bacterium that was originated before 380 million years ago.
The oldest plant was originated about 320 million years ago and the invertebrate animals were originated about 120 million years ago, in Archeozoic and Proterozoic Era respectively.
Invertebrates, vertebrates, fast growing bushes and giant fern trees were developed in Paleozoic era. Paleozoic Era is also called time of amphibian because amphibianswere dominant in this era.
Mesozoic era is also called the time of reptiles because reptiles were abundant in this era. The first dinosaur was formed about 225 million years ago but was extinct during the Cretaceous period. The first bird and mammal were formed around this time.
Cenozoic era is the present era which is called the"time of mammals". In this time, primates and horses were formed about 54 million years ago and rhinoceros and camel like animals were formed about 38 million years ago. The earliest man was formed about 2 million years ago. Thus, man, who is ruling on the earth by his intelligence, is the youngest on the earth.
The dinosaur evolved in Triassic period, developed in the Jurassic period and became extinct in the Cretaceous period of Mesozoic era.
Ancient time is prehistoric. There is no written record on the types of organisms present in that time. People depend on evidences of evolution to know about the organisms. The most reliable evidence is the study of fossils. People have found fossils of dinosaurs that were present on the earth in ancient time. Dinosaurs were dominant in Jurassic period of Mesozoic Era. This period lasted from 240 million years ago to 140 million years ago.
Millions of years ago, there was no favorable environment on the surface of the earth for the living organisms. After continuous agitation and change of different kinds, favorable condition for the evolution of life becomes impossible.
The earth's environment and surface had favorable conditions for larger reptiles that used water as well during the Mesozoic era. During this era, dinosaurs evolved and developed. But after the extinction of animals at the end of Mesozoic era, the conditions became favorable for land animals with lots of cultivable plants that favored human. Because of this dinosaurs evolved earlier than humans.
The two periods in the Quaternary epoch of Cenozoic era are: Pleistocene and Holocene.
The time period and manifestation of life for each one are:
|Period||Time||Manifestation of life|
|Pleistocene||1.8 million years ago to 0.5 million years ago||Primitive human beings and mammoths present.|
|Holocene||0.5 million years ago to today||Modern humans and other mammals present.|
How many year ago the oldest plant was originated?
about 300 million years ago
about 320 million years ago
about 320 billion years ago
about 220 million years ago
The invertebrate animals were originated about ______.
Which era is also called the time of reptiles?
Which one of the era is called time of reptiles?
Which one of the era is called time of amphibian?
Which one of the era is called time of mammals?
The first dinosaur was formed about ______.
225 million years ago
555 million years ago
125 million years ago
55 million years ago
The earliest man was formed about ______.
2o million years ago
2 million years ago
12 million years ago
6 million years ago