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Period: 570 BCE to 246 BCE
Palaeozoic Era
The Paleozoic or Paleozoic era is a division of the geological time scale that belongs to the Phanerozoic eon, with the category of era and erathema. -
Period: 541 BCE to 485 BCE
Cambrian
Its a division of the geologic timescale that belongs to the Paleozoic Era, this is divided into six periods of which the Cambrian occupies the first place preceding the Ordovician. It began about 541 million years ago, after the Proterozoic Aeon, and ended about 485 million years ago. -
520 BCE
First invertebrates
About 3.5 billion years ago, the first microscopic organisms appeared in the ocean. The first invertebrates developed in the oceans. They were soft-bodied animals with a shell or carapace, such as these trilobites. Fish, like the agnathans, appeared. They appeared at the starts of the Cambrian period -
Period: 485 BCE to 444 BCE
Ordovician
It lasted almost 45 million years, beginning 488.3 million years ago and ending 443.7 million years ago. * During this period, the area north of the tropics was almost entirely ocean, and most of the world's land was collected into the southern supercontinent Gondwana. -
460 BCE
Widespread marine algae
Sponges, corals and even primitive fish lived in Ordovician waters. The plant life in the water was red and green algae. They appeared at the starts of Ordovician period -
Period: 444 BCE to 419 BCE
Silurian
The Silurian period occurred from 443 million to 416 million years ago. It was the third period in the Paleozoic Era. It followed the Ordovician Period and preceded the Devonian Period. During this time, continental landmasses were low and sea levels were rising. -
431 BCE
First land plants
The first land plants appeared around 470 million years ago. They first appeared at the starts of the Silurian period. -
Period: 419 BCE to 359 BCE
Devonian
The Devonian period occurred from 416 million to 358 million years ago. It was the fourth period of the Paleozoic Era. It was preceded by the Silurian Period and followed by the Carboniferous Period. -
375 BCE
Fish diversify and first anphibians
These first tetrapods were amphibians and they evolved around 395 million years ago. They appeared at the starts of the Devonian period. -
Period: 359 BCE to 299 BCE
Carboniferous
It lasted from about 359.2 to 299 million years ago* during the late Paleozoic Era. The term "Carboniferous" comes from England, in reference to the rich deposits of coal that occur there. These deposits of coal occur throughout northern Europe, Asia, and midwestern and eastern North America. -
323 BCE
Firts reptiles
Reptiles arose about 310–320 million years ago during the Carboniferous period. -
Period: 299 BCE to 252 BCE
Permian
It is a geologic period and system which spans 47 million years from the end of the Carboniferous period 298.9 million years ago (Mya), to the beginning of the Triassic period 251.902 Mya. -
Period: 252 BCE to 66 BCE
Mesozoic Era
Mesozoic era or secondary era, known zoologically as the age of the dinosaurs or botanically as the era of the cycads, is a division of the geological timescale -
Period: 252 BCE to 201 BCE
Triassic
The triassic Period was the first period of the Mesozoic Era and occurred between 251 million and 199 million years ago. It followed the great mass extinction at the end of the Permian Period and was a time when life outside of the oceans began to diversify. -
234 BCE
First dinosaurs
Approximately 230 million years ago, during the Triassic Period, the dinosaurs appeared, evolved from the reptiles. Plateosaurus was one of the first large plant-eating dinosaurs, a relative of the much larger sauropods. It grew to about 9 meters in length. -
Period: 201 BCE to 145 BCE
Jurassic
The Jurassic period is a geologic period and system that spanned 56 million years from the end of the Triassic Period 201.3 million years ago (Mya) to the beginning of the Cretaceous Period 145 Mya -
Period: 145 BCE to 66 BCE
Cretaceous
The Cretaceous Period was the last and longest segment of the Mesozoic Era. It lasted approximately 79 million years, from the minor extinction event that closed the Jurassic Period about 145.5 million years ago to the Cretaceous-Paleogene (K-Pg) extinction event dated at 65.5 million years ago. -
81 BCE
First plants with flowers
The oldest so far discovered is the 130- million-year-old aquatic plant Montsechia vidalii unearthed in Spain in 2015. However it is thought that flowering plants first appeared much earlier than this, sometime between 250 and 140 million years ago. These plants appeared at the starts of the Cretaceous period. -
Period: 66 BCE to 10
Cenozoic Era
It is the last division of the geological time scale, within what makes up the Phanerozoic Eon (started 541 million years ago and culminates in our present days), together with the Paleozoic and Mesozoic eras. -
Period: 66 BCE to 2 BCE
Tertiary
Tertiary Period, interval of geologic time lasting from approximately 66 million to 2.6 million years ago. ... It is the traditional name for the first of two periods in the Cenozoic Era (66 million years ago to the present); the second is the Quaternary Period (2.6 million years ago to the present). -
65 BCE
Extinction of the Dinosaurs
The Cretaceous-Tertiary extinction event, or the K-T event, is the name given to the die-off of the dinosaurs and other species that took place some 65.5 million years ago. The dinousars extincted in the finals of Cretaceous period and starts of Tertary period -
34 BCE
Diversification of mammals
Humans' early mammal relatives likely diversified 66 million years ago, after the extinction of dinosaurs opened up space for animals such as big cats, horses, elephants and eventually apes to evolve.The mammals appeared at the starts of the Tertiary period -
Period: 2 BCE to 50
Quaternary
The Quaternary Period is a geologic time period that encompasses the most recent 2.6 million years — including the present day. ... The Quaternary Period has involved dramatic climate changes, which affected food resources and brought about the extinction of many species.