What came before the dinosaurs?
What came before the dinosaurs?
Humans might be related to these weird, hairless dogs.
Encyclopædia Britannica, Inc.
Transcript
Before there were humans, there were dinosaurs.
But what came before the dinosaurs?
…Would you believe saber-toothed dogs?
Ken Angielczyk: Therapsids are most easily described as ancient mammal relatives. So modern mammals today belong to a larger group that is called Synapsida. And mammals are the only synapsids that are still alive.
The synapsids that are more mammal-like are called therapsids. Ken: Therapsids and other synapsids really were some of the dominant vertebrates on land before the age of dinosaurs. We think of dinosaurs being these dominant animals, and then they go away, and mammals kind of take over. About 66 million years ago after the extinction of the non-bird dinosaurs.
But in reality, our ancestors and our ancient relatives were kind of more important animals at the time that the first dinosaurs originated. So, what did our ancestors look like? Ken: Probably if you saw it walking down the street, it would look kind of like a dog gone wrong. Its name also sounds like that of a dog gone wrong: gorgonopsian. Ken: They’re one of the first groups of animals ever to evolve kind of a saber-toothed morphology. So lots of people know the saber-toothed cat Smilodon, that has really big, impressive canine teeth.
Gorgonopsians evolved similar teeth like that and did it 250 million years before Smilodon did. Ken: But it would lack a lot of the features that we think of sort of normal dogs having because those features haven’t evolved yet. Ken: It would be hairless. It would lack whiskers. It would lack external ears the way mammals have. Well, what happened to these… creatures? Ken: Some of them become specialized plant eaters. A few of them adopt a climbing lifestyle and probably spent time in trees. Others evolved a molelike way of life where they spent a lot of time digging and living underground. And other therapsids, like our gorgonopsians, became carnivores that were feeding on other large animals. And the evolution of saber teeth that happens in gorgonopsians is probably something that is related to that new way of life. We used to think gorgonopsians were only 265 million years old. But it turns out that they’re not only kinda ugly, they’re really, really old too. Ken: The animal that we found in Majorca is what we think is the very oldest gorgonopsian that’s been found in the fossil record.
And there’s also a very good chance that it is the oldest therapsid that’s been found in the fossil record so far. And now we’re the proud mammalian descendants of weird bald dogs. Enjoy your VIP prehistoric DNA.
The synapsids that are more mammal-like are called therapsids. Ken: Therapsids and other synapsids really were some of the dominant vertebrates on land before the age of dinosaurs. We think of dinosaurs being these dominant animals, and then they go away, and mammals kind of take over. About 66 million years ago after the extinction of the non-bird dinosaurs.
But in reality, our ancestors and our ancient relatives were kind of more important animals at the time that the first dinosaurs originated. So, what did our ancestors look like? Ken: Probably if you saw it walking down the street, it would look kind of like a dog gone wrong. Its name also sounds like that of a dog gone wrong: gorgonopsian. Ken: They’re one of the first groups of animals ever to evolve kind of a saber-toothed morphology. So lots of people know the saber-toothed cat Smilodon, that has really big, impressive canine teeth.
Gorgonopsians evolved similar teeth like that and did it 250 million years before Smilodon did. Ken: But it would lack a lot of the features that we think of sort of normal dogs having because those features haven’t evolved yet. Ken: It would be hairless. It would lack whiskers. It would lack external ears the way mammals have. Well, what happened to these… creatures? Ken: Some of them become specialized plant eaters. A few of them adopt a climbing lifestyle and probably spent time in trees. Others evolved a molelike way of life where they spent a lot of time digging and living underground. And other therapsids, like our gorgonopsians, became carnivores that were feeding on other large animals. And the evolution of saber teeth that happens in gorgonopsians is probably something that is related to that new way of life. We used to think gorgonopsians were only 265 million years old. But it turns out that they’re not only kinda ugly, they’re really, really old too. Ken: The animal that we found in Majorca is what we think is the very oldest gorgonopsian that’s been found in the fossil record.
And there’s also a very good chance that it is the oldest therapsid that’s been found in the fossil record so far. And now we’re the proud mammalian descendants of weird bald dogs. Enjoy your VIP prehistoric DNA.