The current diversity of the planet contains a varied group of vertebrates that we commonly know as "birds", which emerged millions of years ago. Genetic studies have shown that they are related to the extinct dinosaurs and that their most direct living relatives are crocodiles, so they are undoubtedly a very peculiar group.
When the event that led to the extinction of the dinosaurs occurred, many of the birds of the time also disappeared, but others were able to continue their evolutionary path to the current ones. In this article on our site we will talk about the prehistoric living and extinct birds, the relationship they have with dinosaursand we show concrete examples We invite you to continue reading so you know what they are.
What are the prehistoric birds?
The term prehistoric refers to everything that was present or occurred before human beings had developed a way to record this event. In this way, it is clear that there are many species of animals that can be considered prehistoric because their appearance is even prior to our species. Now, within the prehistoric animals we can find many extinct, but also others that are still alive.
In the case of birds, they emerged approximately 150 million years ago, which indicates that they lived with the dinosaurs, so in general we can say they are a prehistoric group. However, a large number of these feathered birds became extinct and their path of evolution led the birds to form the group currently known as "modern birds", which have a common ancestor, but on which there are different positions in relation to each other. it arose before or after the mass extinction event that occurred at the Cretaceous-Paleogene boundary. We count the different theories in the article on Origin and evolution of birds.
Despite the opposing positions, the evidence of recent years allows us to refer that among some primitive geese, true ducks, chickens, as well as rheas and ostriches, we find prehistoric birds that remain currently [1]
How are dinosaurs related to prehistoric birds?
Without a doubt, the approach where dinosaurs are related to birds is really surprising, because what can some delicate and beautiful feathered animals have in common with the fearsome and imposing dinosaurs?
Scientific studies carried out using the fossil record have made it possible to generate a fairly accepted consensus, which refers to birds as a group that evolved and specialized from the theropod dinosaurs, where we find the most fearsome carnivorous dinosaurs, who are described as having hollow bones like those of modern birds and, although their ancestors were carnivores, they later diversified their diet to omnivores or herbivores, depending on the group, just like the birds. For this reason, theropod dinosaurs are still represented by birds today. From the comparison of the fossils of bone structures of theropods, in general it can be said that these, over about 50 million years, experienced a miniaturization of their bodies, in addition to becoming more feathered, showing an enlargement of their breasts and developing wings.
The first theropods weighed about 300 kg, but in the evolutionary process, some 20 or 30 million years later, already they weighed much less, making shrinkage relatively faster. With this reduction in weight and dimensions, these animals began to insert themselves into a new ecological niche, which probably had very little competition, which allowed them to successfully conquer and develop.
In this way, dinosaurs and prehistoric birds have a close evolutionary relationship and, therefore, biological and even ecological, since in relation to this last aspect, for example, the evidence suggests that these dinosaur ancestors of today's birds had arboreal habits, and they could even glide.
Examples of extinct prehistoric birds
Now that we know that current and extinct prehistoric birds did come from dinosaurs, let's get to know some species a little more closely. Starting with the last ones, the group of extinct prehistoric birds is very broad, let's get to know some examples:
Stirton's thunderbird (Dromornis stirtoni)
This was a flightless bird, endemic to Australia, which lived thousands of years ago. It is considered one of the largest birds that ever existed, as it weighed between 450 and 600 kg, and its head was more than half a meter long. Despite these traits, it had a tiny brain compared in size to that of domestic chickens or sparrows.
Pelagornis chilensis
This species corresponded to a prehistoric flying bird of the largest that ever existed. Its remains were found in Chile and allowed to describe that the animal had a wingspan of between 5.25 and 6.10 meters.
Lived approximately about 7 million years ago. In addition to its size, the presence of bone projections that simulated teeth on the beak stands out. On the other hand, it is described as having a pelican-like appearance.
Asteria Bird (Asteriornis maastrichtensis)
This prehistoric bird is related to the ancestor of both ducks and roosters Lived in Europe about 66.7 million years ago, so it was around the time when dinosaurs existed. It is estimated that it could fly and its habitat was coastal areas. His contribution to science has been very valuable because it gives information about the first modern birds that lived at that time.
Elephant Birds (Aepyornithidae)
In Madagascar there was a group of birds that emerged around about 85 million years ago, whichthey became extinct due to human pressure around the 18th century Their name refers to their main characteristic, the enormous size they could reach, which was up to 3 meters high and approximately 650 kg.
Moas (Dinornithiformes)
There was a group of atypical birds that comprised a diversity of species that varied in size, but shared a common trait obtained in their evolutionary process: the absence of wings They lived in New Zealand and depending on the species they could have the size of a modern hen or reach 3 meters in height. They emerged around about 90 million years ago and became extinct around 1400 due to human action. Among its living relatives we find the kiwis, among others.
Other extinct prehistoric birds:
- Dodo (Raphus cucullatus)
- Asian ostrich (Struthio asiaticus)
- Chatham Island Duck (Pachyanas chathamica)
Examples of current prehistoric birds
In some cases, extinct birds are closely related to species that are alive today. Let's get to know some examples of living prehistoric birds:
Family Struthionidae
This is a family of flightless birds, which arose in the Eocene, a period that lasted between 56 and 34 million years, about. Currently, the only living genus is Struthio, within which are the peculiar ostriches
Family Rheidae
This family is in the group of ratites, which are the flightless birds and have a long evolutionary history. In this family there are several species already extinct, currently only three remain alive and are commonly known as ñandúes
Discover in this other post the differences between ostriches and rheas.
Group Galloanserae
This group traditionally called in this way contains two subgroups, within which are located a large number of species with a long history of domestication by humans, which are:
- Galliformes: mainly terrestrial.
- Anseriformes: corresponding to species with aquatic habits.
The ancestors of the group lived with the dinosaurs, however, they became extinct, but the Galloanserae managed to continue their evolutionary path to currently have representatives such as the chickens and the ducks.
