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| © Michael Rosskothen/REX/Shutterstock |
By Katy Prentice, Cricket Media
Picture the scene 150 million years ago. Dinosaurs roamed the land, ichthyosaurs and plesiosaurs were in the oceans, the first mammals scurried around in the trees and giant ferns. But who ruled the skies? —The pterosaurs! They were the first animals with bones to take to the skies. They belonged to a group of reptiles called archosaurs, which also includes dinosaurs and crocodiles. Pterosaurs are often overlooked in favor of their famous cousins, the dinosaurs, but they are just as interesting.
Picture the scene 150 million years ago. Dinosaurs roamed the land, ichthyosaurs and plesiosaurs were in the oceans, the first mammals scurried around in the trees and giant ferns. But who ruled the skies? —The pterosaurs! They were the first animals with bones to take to the skies. They belonged to a group of reptiles called archosaurs, which also includes dinosaurs and crocodiles. Pterosaurs are often overlooked in favor of their famous cousins, the dinosaurs, but they are just as interesting.
A Sea Monster!
The first pterosaur was discovered in 1784 and was mistaken for a sea monster. Since then, palaeontologists have learned much more about them. Pterosaurs, however, died out millions of years ago, so we can only study their fossils. Often, only a few fragments of bones are preserved, but, in a few rare cases, they are so well preserved it is possible to see imprints of the fragile skin that made the pterosaurs’ wings.
The first pterosaurs date back to the Late Triassic, 225 million years ago, and lived for 160 million years. During this time, they evolved into many different types. The first, however, were small. For example, Nemicolopterus had a wing span of 9.8 inches and is the smallest pterosaur we know. Later, they evolved to become the largest flying creatures of all time. Quetzalcoatlus had a wing span of 33–40 feet, which dwarfs the largest flying bird today, the wandering albatross, which has a wing span of 14.7 feet.
Pterosaurs came in all different shapes, which reflected how they lived in different habitats and on different foods. Some had long pointed teeth that were used for catching fish. Others had large flat teeth that probably were used to crack open shellfish. Pterodaustro had more than 1,000 fine teeth to sieve out insect larvae from water, like modern-day flamingos. Some—the Pteranodon, for example— had no teeth at all!
The first pterosaurs date back to the Late Triassic, 225 million years ago, and lived for 160 million years. During this time, they evolved into many different types. The first, however, were small. For example, Nemicolopterus had a wing span of 9.8 inches and is the smallest pterosaur we know. Later, they evolved to become the largest flying creatures of all time. Quetzalcoatlus had a wing span of 33–40 feet, which dwarfs the largest flying bird today, the wandering albatross, which has a wing span of 14.7 feet.
Pterosaurs came in all different shapes, which reflected how they lived in different habitats and on different foods. Some had long pointed teeth that were used for catching fish. Others had large flat teeth that probably were used to crack open shellfish. Pterodaustro had more than 1,000 fine teeth to sieve out insect larvae from water, like modern-day flamingos. Some—the Pteranodon, for example— had no teeth at all!
Meet the Two
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| © Getty INGOLSTADT, GERMANY - MARCH 21: Museum workers prepare a representation of what museum officials claim is the world's biggest discovered winged dinosaur prior to its exhibition at the Altmuehltal Dinosaur Museum on March 21, 2018 in Denkendorf, Germany. Bones of the dinosaur were found in the Transylvanian region of Romania and the museum has dubbed the creature 'Dracula.' The species of the dinosaur is so far unnamed, though it is part of a class of flying dinosaurs called Pterosaurs and is approximately 66 million years old. The wingspan of the reconstructed pterosaur measures 12 meters and when standing the creature measures three and a half meters in height. Original bones of the pterosaur are displayed in a separate display cabinet at the museum. Whether this new species could actually fly is unclear. (Photo by Andreas Gebert/Getty Images) |
Paleontologists now divide pterosaurs into two different types: rhamphorhynchoids and pterodactyloids. Rhamphorhynchoids are the older group, existing from the Late Triassic until the Early Cretaceous. We know about 40 species in this group. The pterodactyloids came later in the Late Jurassic and consist of about 80 known species.
These two groups were very different, not just in the way that they looked, but also in the way that they were able to move. Rhamphorhynchoids had wings that were more similar to those of bats, meaning that they were slower but more agile flyers. For species that are believed to have lived on insects, this would have made hunting easier.
Rhamphorhynchoids probably would have found walking on land difficult. However, their long claws may mean that they could climb trees and cliffs.
Pterodactyloids had wings that resembled more closely those of sea gulls, making them faster flyers and better at gliding. They are thought to have been good walkers. It has been suggested that the gigantic Hatzegopteryx would have been able to wade through shallow water or walk on land to stalk its prey on foot.
These two groups were very different, not just in the way that they looked, but also in the way that they were able to move. Rhamphorhynchoids had wings that were more similar to those of bats, meaning that they were slower but more agile flyers. For species that are believed to have lived on insects, this would have made hunting easier.
Rhamphorhynchoids probably would have found walking on land difficult. However, their long claws may mean that they could climb trees and cliffs.
Pterodactyloids had wings that resembled more closely those of sea gulls, making them faster flyers and better at gliding. They are thought to have been good walkers. It has been suggested that the gigantic Hatzegopteryx would have been able to wade through shallow water or walk on land to stalk its prey on foot.
Making a Checklist
I have been fascinated by pterosaurs since I was very young, so I was thrilled to be able to study these animals as part of my Masters degree work at the University of Bristol in England. My job was to try to find out how the body shapes and features of pterosaurs changed through time. First, I made a list of all the ways members of the pterosaur species differed from each other—in their beaks, eyes, necks, wings, and legs. I then ran calculations through the computer to work out which pterosaurs were most similar and which were most specialized.
What soon became very obvious was that the rhamphorhynchoids and pterodactyloids had very different bodies. We can tell this because a space separates them on the graph. Therefore, if they did have different bodies, then it is likely that they had different lifestyles as well. This fact would make it unlikely that they would need to compete with each other for necessities such as food. Paleontologists originally thought that the pterodactyloids had pushed the rhamphorhynchoids to extinction by outcompeting them.
Second, look at the amount of space covered by the two groups on the graph below. The larger the area covered, the larger the range of body shapes. The rhamphorhynchoids are all in one small area, meaning that they did not change very much throughout their history. The pterodactyloids, however, cover a large area on the graph, meaning they changed a lot during the time they existed. Actually, they evolved into lots of weird and wacky shapes. This is remarkable, as both groups existed for the same amount of time. It is thought that when more rhamphorhynchoid species are discovered, they will be very similar to the ones we already know. But, if additional pterodactyloids are uncovered, they are more likely to have an extreme body shape. Just imagine the creatures that may still be there to be discovered!
What soon became very obvious was that the rhamphorhynchoids and pterodactyloids had very different bodies. We can tell this because a space separates them on the graph. Therefore, if they did have different bodies, then it is likely that they had different lifestyles as well. This fact would make it unlikely that they would need to compete with each other for necessities such as food. Paleontologists originally thought that the pterodactyloids had pushed the rhamphorhynchoids to extinction by outcompeting them.
Second, look at the amount of space covered by the two groups on the graph below. The larger the area covered, the larger the range of body shapes. The rhamphorhynchoids are all in one small area, meaning that they did not change very much throughout their history. The pterodactyloids, however, cover a large area on the graph, meaning they changed a lot during the time they existed. Actually, they evolved into lots of weird and wacky shapes. This is remarkable, as both groups existed for the same amount of time. It is thought that when more rhamphorhynchoid species are discovered, they will be very similar to the ones we already know. But, if additional pterodactyloids are uncovered, they are more likely to have an extreme body shape. Just imagine the creatures that may still be there to be discovered!
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A Lucky Escape!
Birds existed from the Late Jurassic onward. It was once thought that birds outcompeted the pterosaurs, causing pterosaur numbers to decrease. We now know that birds and pterosaurs lived alongside each other for more than 70 million years, which means that they probably interfered very little with each other’s lives. The pterosaurs were all killed in the same asteroid impact that killed the dinosaurs and many other animals and plants 65 million years ago. But, their deaths are unlikely to have had anything to do with birds. The birds just had a lucky escape!
Katy Prentice did her degree in evolution and paleontology at the University of Bristol, England, and is now studying for a Ph.D. in paleontology at Imperial College London.
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Katy Prentice did her degree in evolution and paleontology at the University of Bristol, England, and is now studying for a Ph.D. in paleontology at Imperial College London.
See more at Cricket Media
