How Long Ago Did Dinosaurs Live?<\/h2>\n![\"Megalosaurus\"](\"http:\/\/www.activewild.com\/wp-content\/uploads\/2016\/09\/Megalosaurus.jpg\")
Megalosaurus was the first dinosaur to be named.<\/figcaption><\/figure>\nDinosaurs first appeared between 243 and 231 million years ago.<\/em><\/strong><\/p>\nThey\u2019re big numbers, so it\u2019s worth writing them out in full so you can get an idea just how long ago it was …<\/p>\n
The first dinosaurs appeared between 243,000,000<\/strong> and 231,000,000<\/strong> years ago!<\/p>\nAt this time, the world was going through\u00a0what is known as the ‘Triassic Period’. The Triassic period is part of the geological timescale<\/em><\/strong>. We’ll learn more about this further down the page.<\/p>\nDinosaurs died out around 66 million (66,000,000) years ago.<\/em><\/strong><\/p>\nThat means that dinosaurs lived\u00a0for around 177 million (177,000,000) years.<\/p>\n
We\u2019ve only been around for around 2 million years, so we\u2019ve still got a long way to go to beat the dinosaurs!<\/p><\/blockquote>\n
Are Dinosaurs Still Alive?<\/h2>\n![\"Helmeted](\"http:\/\/www.activewild.com\/wp-content\/uploads\/2016\/04\/Helmeted-Hornbill.jpg\")
A modern day dinosaur: the Helmeted Hornbill<\/figcaption><\/figure>\nIt\u2019s not as crazy as it sounds! In fact, most scientists today consider birds to be dinosaurs<\/strong>! This is because modern classification systems\u00a0(how living things are grouped)\u00a0are concerned with how groups of animals \u2018branch off\u2019 to become new species.<\/p>\nBecause a group of dinosaurs \u2018branched off\u2019 to become birds (over the course of millions of years), birds can be considered to be dinosaurs!<\/p>\n
So, when we say that dinosaurs became extinct 66 million years ago, we\u2019re actually\u00a0talking about all of the dinosaurs that didn\u2019t become birds \u2013 i.e. the \u2018non-avian\u2019 dinosaurs.<\/p>\n
How Long Ago Did Dinosaurs Live: Geological Periods<\/h2>\n![\"Geology\"](\"http:\/\/www.activewild.com\/wp-content\/uploads\/2016\/07\/Paleontology.jpg\")
How long ago did dinosaurs live? As a geologist!<\/figcaption><\/figure>\nYou may have heard about periods of time such as the Triassic, Jurassic and Cretaceous periods, but do\u00a0you know what these names actually mean?<\/p>\n
They\u2019re all geological periods<\/em><\/strong>, and part of the geological timescale<\/em><\/strong>. Geology is the study of rocks. Geological periods all relate to specific layers of rock.<\/p>\nThe geological timescale is a way of looking at the history of the world that directly relates to the very stuff that the world is made of: rock!<\/p><\/blockquote>\n
For example, the Triassic period is the time during which rocks in the Triassic layer were formed.<\/p>\n
The deeper the rock layer, the longer ago it was formed. Therefore, the Triassic period occurred before the Jurassic period, because the Triassic rock layer is deeper than the Jurassic rock layer.<\/p>\n
The geological timescale has different divisions, just like hours are divided into minutes, and minutes are divided into seconds.<\/p>\n
In the geological timescale, eras<\/strong> are divided into periods<\/strong>, which in turn are divided into epochs<\/strong>.<\/p>\nYou can learn more about the geological timescale here: Dinosaur Periods<\/a>.<\/p>\nMesozoic Era (252.17 to 66 million years ago)<\/h3>\n\n- Triassic Period<\/strong> (252.17 to 201.3 million years ago)\n
\n- Early Triassic<\/strong> Epoch (252.17 – 247.2 million years ago)<\/li>\n
- Middle Triassic<\/strong> Epoch (247.2 – 237 million years ago)<\/li>\n
- Late Triassic<\/strong> Epoch (237 – 201.3 million years ago)<\/li>\n<\/ul>\n<\/li>\n
- Jurassic Period<\/strong> (201.3 \u2013 145 million years ago)\n
\n- Early Jurassic<\/strong> Epoch (201.3 to 174.1 million years ago)<\/li>\n
- Middle Jurassic<\/strong> Epoch (174.1 to 163.5 million years ago)<\/li>\n
- Late Jurassic<\/strong> Epoch (163.5 to 145 million years ago)<\/li>\n<\/ul>\n<\/li>\n
- Cretaceous Period<\/strong> (145 \u2013 66 million years ago)\n
\n- Early Cretaceous<\/strong> Epoch (145 to 100.5 million years ago)<\/li>\n
- Late Cretaceous<\/strong> Epoch (100.5 to 66 million years ago)<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n
How Long Ago Did Dinosaurs Live: The Triassic Period<\/h2>\n
![\"Eoraptor](\"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/4\/4d\/Eoraptor_resto._01.png\/1024px-Eoraptor_resto._01.png\")
<\/a><\/p>\nThe Eoraptor, shown above, was one of the earliest dinosaurs.<\/em><\/p>\nAs we\u2019ve seen, the earliest estimate as to when dinosaurs appeared was around 243 million (243,000,000) years ago.<\/p>\n
Of course, dinosaurs didn\u2019t just appear out of thin air. They evolved from primitive reptiles, which themselves had evolved from amphibians around 350 million years ago.<\/p>\n
A group of early reptiles called Archosaurs<\/strong> became dominant in the early Triassic period. Prior to this, a group of animals called the Synapsids<\/strong> \u2013 which would go on to become mammals \u2013 had been in charge. Their time would come!<\/p>\nArchosaurs branched into crocodilians<\/strong> (which, with the greatest respect to modern-day crocodiles and alligators, haven\u2019t really changed much over the years), pterosaurs<\/strong> (flying reptiles, such as Pterodactylus<\/em><\/a>), and dinosaurs<\/strong>.<\/p>\nDinosaurs appeared sometime during the middle or late epochs of the Triassic period.<\/p>\n
The earliest dinosaur that we know about is the Eoraptor<\/strong>, a small predator that walked on two legs.<\/p>\nOf course, dinosaurs weren\u2019t the only animals alive back then; insects, lizards, frogs, fish, turtles and other creatures had already made an appearance.<\/p>\n
Triassic\u2013Jurassic Extinction Event<\/h2>\n![\"Allosaurus\"](\"http:\/\/www.activewild.com\/wp-content\/uploads\/2016\/07\/Allosaurus.jpg\")
Allosaurus was a Jurassic predator.<\/figcaption><\/figure>\nAt the end of the Triassic period, around 201.3 million years ago, something caused over 50% of all species to become extinct. This is known as the Triassic\u2013Jurassic extinction event<\/strong>.<\/p>\nWe don\u2019t know exactly what caused this; likely explanations include an asteroid impact, or volcanic activity.<\/p>\n
Jurassic & Cretaceous Periods<\/h2>\n
Whatever it was that happened at the end of the Triassic period enabled the dinosaurs to become the dominant land animals in the Jurassic period<\/strong>.<\/p>\nDuring the Jurassic period, dinosaurs branched off into several types, including huge sauropods such as Diplodocus<\/a>, and fearsome predators such as Allosaurus<\/a>. The early birds, such as Archaeopteryx, also began to appear.<\/p>\nIn the Cretaceous period, more of the familiar names appeared, including dinosaurs such as T Rex<\/a>, Spinosaurus<\/a> and Triceratops<\/a>.<\/p>\nCretaceous\u2013Paleogene Extinction Event<\/strong><\/h2>\n![\"Meteor\"](\"http:\/\/www.activewild.com\/wp-content\/uploads\/2016\/07\/Meteorite-Hitting-Earth.jpg\")
Scientists believe that a large asteroid strike caused the extinction of the dinosaurs.<\/figcaption><\/figure>\nHowever, the age of the dinosaurs came to an end around 66 million years ago with the Cretaceous\u2013Paleogene extinction event<\/strong>. This caused around 75% of all species<\/strong> to become extinct, including all of the dinosaurs that hadn\u2019t evolved into birds.<\/p>\nYou can read more about the Cretaceous\u2013Paleogene extinction event here<\/a>.<\/strong><\/p>\nHow long ago did dinosaurs live? Conclusion<\/h2>\n
Next time you\u2019re asked \u2018How long ago did dinosaurs live?\u2019 here\u2019s your reply:<\/p>\n
Dinosaurs lived from somewhere between 243 and 231 million years ago<\/strong> right up to the Cretaceous\u2013Paleogene extinction event, which occurred around 66 million years ago<\/strong>.<\/p>\nDinosaurs lived for around 177 million years. That\u2019s much longer than they\u2019ve been extinct.<\/p>\n
However, dinosaurs still exist \u2013\u00a0in the shape of birds \u2013 so strictly speaking they\u2019re still alive!<\/p>\n
We hope that you enjoyed this page. Feel free to link to it or to share it on social media using the buttons provided. You can find more awesome dinosaur information at our main Dinosaur Facts page<\/a>.<\/p>\n
Dinosaurs first appeared between 243 and 231 million years ago.<\/em><\/strong><\/p>\n They\u2019re big numbers, so it\u2019s worth writing them out in full so you can get an idea just how long ago it was …<\/p>\n The first dinosaurs appeared between 243,000,000<\/strong> and 231,000,000<\/strong> years ago!<\/p>\n At this time, the world was going through\u00a0what is known as the ‘Triassic Period’. The Triassic period is part of the geological timescale<\/em><\/strong>. We’ll learn more about this further down the page.<\/p>\n Dinosaurs died out around 66 million (66,000,000) years ago.<\/em><\/strong><\/p>\n That means that dinosaurs lived\u00a0for around 177 million (177,000,000) years.<\/p>\n We\u2019ve only been around for around 2 million years, so we\u2019ve still got a long way to go to beat the dinosaurs!<\/p><\/blockquote>\n It\u2019s not as crazy as it sounds! In fact, most scientists today consider birds to be dinosaurs<\/strong>! This is because modern classification systems\u00a0(how living things are grouped)\u00a0are concerned with how groups of animals \u2018branch off\u2019 to become new species.<\/p>\n Because a group of dinosaurs \u2018branched off\u2019 to become birds (over the course of millions of years), birds can be considered to be dinosaurs!<\/p>\n So, when we say that dinosaurs became extinct 66 million years ago, we\u2019re actually\u00a0talking about all of the dinosaurs that didn\u2019t become birds \u2013 i.e. the \u2018non-avian\u2019 dinosaurs.<\/p>\n You may have heard about periods of time such as the Triassic, Jurassic and Cretaceous periods, but do\u00a0you know what these names actually mean?<\/p>\n They\u2019re all geological periods<\/em><\/strong>, and part of the geological timescale<\/em><\/strong>. Geology is the study of rocks. Geological periods all relate to specific layers of rock.<\/p>\n The geological timescale is a way of looking at the history of the world that directly relates to the very stuff that the world is made of: rock!<\/p><\/blockquote>\n For example, the Triassic period is the time during which rocks in the Triassic layer were formed.<\/p>\n The deeper the rock layer, the longer ago it was formed. Therefore, the Triassic period occurred before the Jurassic period, because the Triassic rock layer is deeper than the Jurassic rock layer.<\/p>\n The geological timescale has different divisions, just like hours are divided into minutes, and minutes are divided into seconds.<\/p>\n In the geological timescale, eras<\/strong> are divided into periods<\/strong>, which in turn are divided into epochs<\/strong>.<\/p>\n You can learn more about the geological timescale here: Dinosaur Periods<\/a>.<\/p>\n The Eoraptor, shown above, was one of the earliest dinosaurs.<\/em><\/p>\n As we\u2019ve seen, the earliest estimate as to when dinosaurs appeared was around 243 million (243,000,000) years ago.<\/p>\n Of course, dinosaurs didn\u2019t just appear out of thin air. They evolved from primitive reptiles, which themselves had evolved from amphibians around 350 million years ago.<\/p>\n A group of early reptiles called Archosaurs<\/strong> became dominant in the early Triassic period. Prior to this, a group of animals called the Synapsids<\/strong> \u2013 which would go on to become mammals \u2013 had been in charge. Their time would come!<\/p>\n Archosaurs branched into crocodilians<\/strong> (which, with the greatest respect to modern-day crocodiles and alligators, haven\u2019t really changed much over the years), pterosaurs<\/strong> (flying reptiles, such as Pterodactylus<\/em><\/a>), and dinosaurs<\/strong>.<\/p>\n Dinosaurs appeared sometime during the middle or late epochs of the Triassic period.<\/p>\n The earliest dinosaur that we know about is the Eoraptor<\/strong>, a small predator that walked on two legs.<\/p>\n Of course, dinosaurs weren\u2019t the only animals alive back then; insects, lizards, frogs, fish, turtles and other creatures had already made an appearance.<\/p>\n At the end of the Triassic period, around 201.3 million years ago, something caused over 50% of all species to become extinct. This is known as the Triassic\u2013Jurassic extinction event<\/strong>.<\/p>\n We don\u2019t know exactly what caused this; likely explanations include an asteroid impact, or volcanic activity.<\/p>\n Whatever it was that happened at the end of the Triassic period enabled the dinosaurs to become the dominant land animals in the Jurassic period<\/strong>.<\/p>\n During the Jurassic period, dinosaurs branched off into several types, including huge sauropods such as Diplodocus<\/a>, and fearsome predators such as Allosaurus<\/a>. The early birds, such as Archaeopteryx, also began to appear.<\/p>\n In the Cretaceous period, more of the familiar names appeared, including dinosaurs such as T Rex<\/a>, Spinosaurus<\/a> and Triceratops<\/a>.<\/p>\n However, the age of the dinosaurs came to an end around 66 million years ago with the Cretaceous\u2013Paleogene extinction event<\/strong>. This caused around 75% of all species<\/strong> to become extinct, including all of the dinosaurs that hadn\u2019t evolved into birds.<\/p>\n You can read more about the Cretaceous\u2013Paleogene extinction event here<\/a>.<\/strong><\/p>\n Next time you\u2019re asked \u2018How long ago did dinosaurs live?\u2019 here\u2019s your reply:<\/p>\n Dinosaurs lived from somewhere between 243 and 231 million years ago<\/strong> right up to the Cretaceous\u2013Paleogene extinction event, which occurred around 66 million years ago<\/strong>.<\/p>\n Dinosaurs lived for around 177 million years. That\u2019s much longer than they\u2019ve been extinct.<\/p>\n However, dinosaurs still exist \u2013\u00a0in the shape of birds \u2013 so strictly speaking they\u2019re still alive!<\/p>\n We hope that you enjoyed this page. Feel free to link to it or to share it on social media using the buttons provided. You can find more awesome dinosaur information at our main Dinosaur Facts page<\/a>.<\/p>\nAre Dinosaurs Still Alive?<\/h2>\n
How Long Ago Did Dinosaurs Live: Geological Periods<\/h2>\n
Mesozoic Era (252.17 to 66 million years ago)<\/h3>\n
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How Long Ago Did Dinosaurs Live: The Triassic Period<\/h2>\n
<\/a><\/p>\nTriassic\u2013Jurassic Extinction Event<\/h2>\n
Jurassic & Cretaceous Periods<\/h2>\n
Cretaceous\u2013Paleogene Extinction Event<\/strong><\/h2>\n
How long ago did dinosaurs live? Conclusion<\/h2>\n