I’ve gone my entire life being told “that’s not a dinosaur that’s a (insert what it is) but why? What’s makes one giant lizard a Dinosaur but a different giant reptile not a dinosaur?
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This is the most fun I’ve had randomly learning stuff about dinosaurs since the last time I randomly learned stuff about dinosaurs. How am I many decades into my life and I still love randomly learning stuff about dinosaurs?
This is the most fun I’ve had randomly learning stuff about dinosaurs since the last time I randomly learned stuff about dinosaurs. How am I many decades into my life and I still love randomly learning stuff about dinosaurs?
It’s more “ELI9-12”, but if you want to take an accessible and comprehensive deep dive into the evolutionary paths of prehistoric animals, I highly recommend “Dinosaur Empire!” by Abby Howard. It’s the first comic book in a series all about the concepts of the evolutionary tree, it’s amazingly detailed and very fun.
It’s more “ELI9-12”, but if you want to take an accessible and comprehensive deep dive into the evolutionary paths of prehistoric animals, I highly recommend “Dinosaur Empire!” by Abby Howard. It’s the first comic book in a series all about the concepts of the evolutionary tree, it’s amazingly detailed and very fun.
It’s more “ELI9-12”, but if you want to take an accessible and comprehensive deep dive into the evolutionary paths of prehistoric animals, I highly recommend “Dinosaur Empire!” by Abby Howard. It’s the first comic book in a series all about the concepts of the evolutionary tree, it’s amazingly detailed and very fun.
The term “dinosaur” has been defined by scientist to describe a group of related creatures.
Wether something is or is not a dinosaurs has nothing to do with its size or reptileness or when it lived or wether it is extinct.
People had been coming across fossils of dinosaurs and other for a long time but didn’t really recognize them for what they are until the mid 1800s.
Some of the first few found are today known as Megalosaurus and Iguanodon and when the term dinosaur was coined it was created to basically describe creatures like those two.
The technical definition involves picking two dinosaurs like Iguanodon and Megalosaurs and say that a dinosaur is every creature that descended from the last common ancestor of those two.
You can replace the two examples with more well known ones like T-Rex and Triceratops the result is the same.
So a dinosaur is every creature that is part of the same family as the first few dinosaurs we encountered.
This means that other big extinct creatures that are not part of that family are not dinosaurs.
You have creatures like Dimetrodon which lived long before the dinosaurs and is more closely related to us than to the Dinosaurs.
You have flying reptiles and aquatic reptiles like pteranodon or Plesiosaurs.
If we had encountered one of them among the first giant extinct fossils our definition for dinosaur might have been broader.
It is probably for the best though.
The fact that we define what a dinosaur is based on common descent means that birds are technically dinosaurs, this is more obvious for some birds than for others, but still true for all of the.
If we had included some of the other big extinct reptiles in the original definition a bunch of living reptiles would now also be technically dinosaurs.
It might work for alligators and crocs and snakes and some other group but could get quickly out of hand if we defined it broadly enough
If we had included things like Dimetrodon you and I might qualify as dinosaurs and that would be stupid and useless.
Having to look at a chicken and realize that it is basically a tiny T-Rex cousin is bad enough.
The term “dinosaur” has been defined by scientist to describe a group of related creatures.
Wether something is or is not a dinosaurs has nothing to do with its size or reptileness or when it lived or wether it is extinct.
People had been coming across fossils of dinosaurs and other for a long time but didn’t really recognize them for what they are until the mid 1800s.
Some of the first few found are today known as Megalosaurus and Iguanodon and when the term dinosaur was coined it was created to basically describe creatures like those two.
The technical definition involves picking two dinosaurs like Iguanodon and Megalosaurs and say that a dinosaur is every creature that descended from the last common ancestor of those two.
You can replace the two examples with more well known ones like T-Rex and Triceratops the result is the same.
So a dinosaur is every creature that is part of the same family as the first few dinosaurs we encountered.
This means that other big extinct creatures that are not part of that family are not dinosaurs.
You have creatures like Dimetrodon which lived long before the dinosaurs and is more closely related to us than to the Dinosaurs.
You have flying reptiles and aquatic reptiles like pteranodon or Plesiosaurs.
If we had encountered one of them among the first giant extinct fossils our definition for dinosaur might have been broader.
It is probably for the best though.
The fact that we define what a dinosaur is based on common descent means that birds are technically dinosaurs, this is more obvious for some birds than for others, but still true for all of the.
If we had included some of the other big extinct reptiles in the original definition a bunch of living reptiles would now also be technically dinosaurs.
It might work for alligators and crocs and snakes and some other group but could get quickly out of hand if we defined it broadly enough
If we had included things like Dimetrodon you and I might qualify as dinosaurs and that would be stupid and useless.
Having to look at a chicken and realize that it is basically a tiny T-Rex cousin is bad enough.
The term “dinosaur” has been defined by scientist to describe a group of related creatures.
Wether something is or is not a dinosaurs has nothing to do with its size or reptileness or when it lived or wether it is extinct.
People had been coming across fossils of dinosaurs and other for a long time but didn’t really recognize them for what they are until the mid 1800s.
Some of the first few found are today known as Megalosaurus and Iguanodon and when the term dinosaur was coined it was created to basically describe creatures like those two.
The technical definition involves picking two dinosaurs like Iguanodon and Megalosaurs and say that a dinosaur is every creature that descended from the last common ancestor of those two.
You can replace the two examples with more well known ones like T-Rex and Triceratops the result is the same.
So a dinosaur is every creature that is part of the same family as the first few dinosaurs we encountered.
This means that other big extinct creatures that are not part of that family are not dinosaurs.
You have creatures like Dimetrodon which lived long before the dinosaurs and is more closely related to us than to the Dinosaurs.
You have flying reptiles and aquatic reptiles like pteranodon or Plesiosaurs.
If we had encountered one of them among the first giant extinct fossils our definition for dinosaur might have been broader.
It is probably for the best though.
The fact that we define what a dinosaur is based on common descent means that birds are technically dinosaurs, this is more obvious for some birds than for others, but still true for all of the.
If we had included some of the other big extinct reptiles in the original definition a bunch of living reptiles would now also be technically dinosaurs.
It might work for alligators and crocs and snakes and some other group but could get quickly out of hand if we defined it broadly enough
If we had included things like Dimetrodon you and I might qualify as dinosaurs and that would be stupid and useless.
Having to look at a chicken and realize that it is basically a tiny T-Rex cousin is bad enough.
Dinosaurs are not lizards at all, lizards are a completely different branch of the reptile family tree.
Dinosaurs are a biological *clade,* meaning all of the species descended from a particular common ancestor. Typically, the dinosaur clade is described as everything descending from the most recent common ancestor of Triceratops and modern birds and are distinguished by the structure of their hips, ankles, and some other bones. The first dinosaur, i.e. the most recent common ancestor of all dinosaurs, is estimated to have lived around 230 million years ago. Other than birds (which *are* dinosaurs) the closest living relatives to dinosaurs are the crocodiles; both dinosaurs and crocodiles belong to a group of reptiles called “archosaurs.”
Things that are not dinosaurs:
1. Dimetrodon: Dimetrodon went extinct 40 million years before the first dinosaurs evolved, and are therefore excluded based on the above definition. Moreover, dimetrodon is not even particularly closely related to dinosaurs and it is a stretch to even call it a “reptile;” it’s actually much more closely related to mammals than any living reptile. Their (and our) last common ancestor with dinosaurs would have lived around 320 million years ago.
2. Pterosaurs: Pterosaurs are in fact archosaurs, part of the same group as dinosaurs and crocodiles, but split off shortly before dinosaurs evolved making them one of the dinosaurs’ closest relatives. They lived alongside dinosaurs and went extinct around the same time. Although they could fly, they evolved flight completely independently from birds, and were physiologically more like bats, with membranes of skin stretched over their fingers.
3. Marine reptiles, i.e. the ichthyosaurs, plesiosaurs, mosasaurs, etc: Where some of these groups belong on the reptile family tree is somewhat unclear, but they are not dinosaurs. Ichthyosaurs are very mysterious in their origins, but fossil evidence shows they definitely evolved before dinosaurs. Plesiosaurs are also difficult to classify, but the modern consensus is that they are related to turtles. Mosasaurs are unambiguously lizards, and are closely related to snakes and monitor lizards. Generally speaking, there were no marine dinosaurs (although some, like Spinosaurus, may have been semi-aquatic).
Dinosaurs are not lizards at all, lizards are a completely different branch of the reptile family tree.
Dinosaurs are a biological *clade,* meaning all of the species descended from a particular common ancestor. Typically, the dinosaur clade is described as everything descending from the most recent common ancestor of Triceratops and modern birds and are distinguished by the structure of their hips, ankles, and some other bones. The first dinosaur, i.e. the most recent common ancestor of all dinosaurs, is estimated to have lived around 230 million years ago. Other than birds (which *are* dinosaurs) the closest living relatives to dinosaurs are the crocodiles; both dinosaurs and crocodiles belong to a group of reptiles called “archosaurs.”
Things that are not dinosaurs:
1. Dimetrodon: Dimetrodon went extinct 40 million years before the first dinosaurs evolved, and are therefore excluded based on the above definition. Moreover, dimetrodon is not even particularly closely related to dinosaurs and it is a stretch to even call it a “reptile;” it’s actually much more closely related to mammals than any living reptile. Their (and our) last common ancestor with dinosaurs would have lived around 320 million years ago.
2. Pterosaurs: Pterosaurs are in fact archosaurs, part of the same group as dinosaurs and crocodiles, but split off shortly before dinosaurs evolved making them one of the dinosaurs’ closest relatives. They lived alongside dinosaurs and went extinct around the same time. Although they could fly, they evolved flight completely independently from birds, and were physiologically more like bats, with membranes of skin stretched over their fingers.
3. Marine reptiles, i.e. the ichthyosaurs, plesiosaurs, mosasaurs, etc: Where some of these groups belong on the reptile family tree is somewhat unclear, but they are not dinosaurs. Ichthyosaurs are very mysterious in their origins, but fossil evidence shows they definitely evolved before dinosaurs. Plesiosaurs are also difficult to classify, but the modern consensus is that they are related to turtles. Mosasaurs are unambiguously lizards, and are closely related to snakes and monitor lizards. Generally speaking, there were no marine dinosaurs (although some, like Spinosaurus, may have been semi-aquatic).
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