These are periods in the geologic timescale, spanning from 145 million years ago (Cretaceous) to 443 million years ago (Ordovician). Each period represents a distinct time in Earth's history characterized by specific events and changes in life forms, such as the extinction of dinosaurs in the Cretaceous period or the diversification of marine life in the Ordovician period.
The major subdivisions are the Precambrian, Palaeozoic, Mesozoic and Cenozoic, which are subdivided into Archean and Proterozoic (Precambrian), Cambrian, Ordovician, Silurian, Devonian, Carboniferous (or Missisipian and Pennsylvanian in the US) and Permian (Palaeozoic), Triassic, Jurassic and Cretaceous (Mesozoic) and Tertiary and Quaternary (Cenozoic). For a graphical representation, see http://geomaps.wr.usgs.gov/socal/geology/geologic_history/images/geologic_time_scale.jpg
They are both time periods of the early Paleozoic. The Ordovician was approximately 490 million years ago, to 440 million years ago. The Silurian was approximately 440 million years ago, to 416 million years ago. The Silurian was the period immediately after the Ordovician. The two periods were divided by the second largest Mass extinction in history.
There were three geological periods in the Mesozoic Era(251 - 65Ma).The Triassic Period(251 - 199Ma),the Jurassic period(199 - 145Ma) &the Cretaceous Period(145 - 65Ma).
Triassic, Jurassic and Cretaceous.
The Phanerozoic Eon is divided into three major eras: the Paleozoic Era, the Mesozoic Era, and the Cenozoic Era. The Paleozoic Era is further divided into six periods: Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and Permian. The Mesozoic Era is divided into three periods: Triassic, Jurassic, and Cretaceous. The Cenozoic Era is divided into two periods: Paleogene and Neogene.
there are different periods in each era. In the Cenozoic era, there are 2 periods, Quaternary and Tertiary. Mesozoic era has 3 periods, Cretaceous, Jurassic, and Triassic. Paleozoic has 7 periods, Permian, Carboniferous, Devonian, Silurian, Ordovician, and Cambrian. Precambrian is just the present, no time periods in it.
Devonian, Carboniferous and Permian Periods
cretaceous,jurassic, and triassic
Triassic Jurassic and Cretaceous
That is easy, the first is precambrian time, next you get the paleozoic era, which has Cambrian, ordovician, silurian, denovonian, carbonferious periods, Next you get the mesozoic era which contains the next three, which are triassic, jurrasic, and cretacous periods. Lasty you get the Cenozoic era which contains the last two which are the tertiary, and the quaternary!
The main dinosaur periods were the Triassic, Jurassic and Cretaceous periods. they were in the mesozoic era. there were other periods before dinosaurs like the carboniferous.