Garden Wildlife
             Garden Wildlife
       Garden Wildlife
             Garden Wildlife
  • AboutAbout
  • ContactContact
  • AboutAbout
  • ContactContact
  • HomeHome
  • HomeHome
Dinosaurs in the garden?
 
Yes, there really are dinosaurs in your garden!
 
Palaeontologists and evolutionary biologists have conclusively proved that birds are really part of the ‘dinosaur’ group, not some separate distinct vertebrate line of descent like mammals or amphibians. We call them birds and think of them as utterly different because they are separated from their dinosaur cousins by tens of millions of years evolution. They are the only dinosaurs that survived the meteorite holocaust at the end of the Cretaceous period 66 million years ago and so they appear unique in the modern world. But comparative anatomy of birds and some dinosaurs show remarkable similarities between the two groups.
 
 
 
 
 
 
Now we know that birds are an integral part of the group of vertebrates commonly called dinosaurs.  The group of dinosaurs that gave rise to modern birds is the Theropoda, which includes the notorious tyrannosaurs and the velociraptors (see the film Jurassic Park for imaginative reconstruction of these creatures…).  Most theropods were non-flying beasts but they were warm-blooded and had a wishbone like birds.
 
Some, perhaps many animals in the theropod group had feathers which would have been evolved for insulation. Theropods also seem to have had similar breathing systems to birds and their bones were hollow like those of birds with air sacs. See our page on bird biology for an explanation of why this is significant.  Some of the dinosaur relatives of birds had an evolutionary tendency to grow smaller, in contrast to the more familiar giant predators we see in museums. Many of these features would have been present in non-flying dinosaurs but they would have been needed for adopting flight as a means of travel – these features made it easier for flight to evolve.
 
Two of the earliest unequivocal birds from the Late Cretaceous are the gull-like Ichthyornis  and the cormorant-like Hesperornis. Both are classed within Avialae together with all modern birds.
 
The perching Passeriform birds which are 60% of all modern species, first appeared well after the Cretaceous extinction event in the Oligocene period about 30 million years ago.
 
 
 
When the late Jurassic (150 million years ago) fossil dinosaur/bird, Archaeopteryx was discovered in 1861 it was recognised that this creature had many bird-like features, notably wings and feathers but it also showed many reptilian features such as teeth and long bony tail. 
 
Its evolutionary connection to the dinosaurs was considered rather spurious until new evidence came to light. It was assumed that birds had a reptile-like ancestor way back before the dinosaurs evolved.
Sinosauropteryx
Archaeopteryx
The upshot of all this  is that there is no clear distinction between the theropod dinosaurs of 150 million years ago and the line of descent leading to the modern birds – any sensible classification puts the birds squarely as a group of dinosaurs, rather as bats are part of the mammalian evolutionary line. The difficulty most of us find in appreciating this is that there are lots of other mammals alive alongside the bats which makes the comparison much easier, while birds are alone in the modern world with no other dinosaurs for comparison. Imagine if bats were the only surviving mammals – what would intelligent dinosaurs make of them?
 
When I watch a magpie swaggering across the lawn I think of the velociraptors and wonder how they would have moved and looked – would they have seemed in any way familiar?
 
Finding out more:
 
Gee, H. (1998) Birds and inosaurs -  the debate is over. Nature  available here.
Singer, E. (2015) How dinosaurs shrank and became birds. Quanta magazine available here
 
 
Page written by Roy Smith compiled by Steve Head
 
Ichthyornis
Hesperornis
Archaeopteryx reconstruction
The discovery of many new feathered fossils from China dating from the time of the dinosaurs in China supported the hypothesis (which had been brewing through the late 20th century) that birds evolved from dinosaur stock.
 
These fossils included some obvious birds, complete with feathered wings and resembling modern birds, and some creatures that resembled bird-like dinosaurs with feathers, and others such as Sinosauropteryx that were very clearly ‘ordinary’ dinosaurs with feathers.
Dinosaurs in the garden?
 
Yes, there really are dinosaurs in your garden!
 
Palaeontologists and evolutionary biologists have conclusively proved that birds are really part of the ‘dinosaur’ group, not some separate distinct vertebrate line of descent like mammals or amphibians. We call them birds and think of them as utterly different because they are separated from their dinosaur cousins by tens of millions of years evolution. They are the only dinosaurs that survived the meteorite holocaust at the end of the Cretaceous period 66 million years ago and so they appear unique in the modern world. But comparative anatomy of birds and some dinosaurs show remarkable similarities between the two groups.
 
 
 
 
 
 
When the late Jurassic (150 million years ago) fossil dinosaur/bird, Archaeopteryx was discovered in 1861 it was recognised that this creature had many bird-like features, notably wings and feathers but it also showed many reptilian features such as teeth and long bony tail. 
 
Its evolutionary connection to the dinosaurs was considered rather spurious until new evidence came to light. It was assumed that birds had a reptile-like ancestor way back before the dinosaurs evolved.
Archaeopteryx
Archaeopteryx reconstruction
Sinosauropteryx
The discovery of many new feathered fossils from China dating from the time of the dinosaurs in China supported the hypothesis (which had been brewing through the late 20th century) that birds evolved from dinosaur stock.
 
These fossils included some obvious birds, complete with feathered wings and resembling modern birds, and some creatures that resembled bird-like dinosaurs with feathers, and others such as Sinosauropteryx that were very clearly ‘ordinary’ dinosaurs with feathers.
 
Now we know that birds are an integral part of the group of vertebrates commonly called dinosaurs.  The group of dinosaurs that gave rise to modern birds is the Theropoda, which includes the notorious tyrannosaurs and the velociraptors (see the film Jurassic Park for imaginative reconstruction of these creatures…).  Most theropods were non-flying beasts but they were warm-blooded and had a wishbone like birds.
 
Some, perhaps many animals in the theropod group had feathers which would have been evolved for insulation. Theropods also seem to have had similar breathing systems to birds and their bones were hollow like those of birds with air sacs. See our page on bird biology for an explanation of why this is significant.  Some of the dinosaur relatives of birds had an evolutionary tendency to grow smaller, in contrast to the more familiar giant predators we see in museums. Many of these features would have been present in non-flying dinosaurs but they would have been needed for adopting flight as a means of travel – these features made it easier for flight to evolve.
 
Two of the earliest unequivocal birds from the Late Cretaceous are the gull-like Ichthyornis  and the cormorant-like Hesperornis. Both are classed within Avialae together with all modern birds.
 
The perching Passeriform birds which are 60% of all modern species, first appeared well after the Cretaceous extinction event in the Oligocene period about 30 million years ago.
Now we know that birds are an integral part of the group of vertebrates commonly called dinosaurs.  The group of dinosaurs that gave rise to modern birds is the Theropoda, which includes the notorious tyrannosaurs and the velociraptors (see the film Jurassic Park for imaginative reconstruction of these creatures…).  Most theropods were non-flying beasts but they were warm-blooded and had a wishbone like birds.
 
Some, perhaps many animals in the theropod group had feathers which would have been evolved for insulation. Theropods also seem to have had similar breathing systems to birds and their bones were hollow like those of birds with air sacs. See our page on bird biology for an explanation of why this is significant.  Some of the dinosaur relatives of birds had an evolutionary tendency to grow smaller, in contrast to the more familiar giant predators we see in museums. Many of these features would have been present in non-flying dinosaurs but they would have been needed for adopting flight as a means of travel – these features made it easier for flight to evolve.
 
Two of the earliest unequivocal birds from the Late Cretaceous are the gull-like Ichthyornis  and the cormorant-like Hesperornis. Both are classed within Avialae together with all modern birds.
 
The perching Passeriform birds which are 60% of all modern species, first appeared well after the Cretaceous extinction event in the Oligocene period about 30 million years ago.
 
 
 
The upshot of all this  is that there is no clear distinction between the theropod dinosaurs of 150 million years ago and the line of descent leading to the modern birds – any sensible classification puts the birds squarely as a group of dinosaurs, rather as bats are part of the mammalian evolutionary line. The difficulty most of us find in appreciating this is that there are lots of other mammals alive alongside the bats which makes the comparison much easier, while birds are alone in the modern world with no other dinosaurs for comparison. Imagine if bats were the only surviving mammals – what would intelligent dinosaurs make of them?
 
When I watch a magpie swaggering across the lawn I think of the velociraptors and wonder how they would have moved and looked – would they have seemed in any way familiar?
 
Finding out more:
 
Gee, H. (1998) Birds and inosaurs -  the debate is over. Nature  available here.
Singer, E. (2015) How dinosaurs shrank and became birds. Quanta magazine available here
 
 
Page written by Roy Smith compiled by Steve Head
 
Ichthyornis
Hesperornis