The terrifying bird inherited the "legacy" of the dinosaurs!

In today's South America, there lives a strange-looking bird with a tall stature, long legs, and a well-developed horny beak with a hook like a bird of prey. This is the crane . The red-legged crane (Cariama cristata) and the black-legged crane (Chunga burmeisteri) are the only surviving members of this family. Their main prey is small rodents, snakes, lizards, insects and amphibians. When hunting, they will bite the prey with their beaks and hit it violently.

Although they can fly, cranes are excellent at running. They only fly into trees to avoid predators or rest. They mainly move on the ground on a daily basis and their overall habits tend to be terrestrial.

Red-legged Crane (left), Black-legged Crane (right) [not actual size ratio] Image source: ebird

Although today the diversity of the entire order Cariamiformes has almost collapsed, in the nearly 50 million years after the extinction of the dinosaurs, the diversity and distribution of Cariamiformes were far greater than they are today, occupying every continent in the world except Australia and Antarctica.

As the descendants of dinosaurs, they once continued the glory of the previous dynasty, competed with the emerging mammalian empire, and placed all living creatures within their sphere of influence under the rule of their giant beaks!

A crane is not a crane

The order Gruiformes, to which the storks belong, is a very ancient branch of birds that originated in the Paleocene Epoch shortly after the extinction of dinosaurs. The earliest fossils were found in Germany at that time.

In the early years, based on their skeletal morphology, the crane family was considered to be closely related to cranes and was naturally classified into the order Gruiformes. This is also the origin of the "crane" in its name.

The early "garbage can" state of Gruiformes, source: Britannica

However, DNA-based research in recent years has shown that the Gruiformes is a branch of terrestrial birds belonging to the Australavis order. Its close relatives are the Passeriformes, Psittaciformes, and Falconiformes, and it originated from the Gondwana continent.

The classification position of the order Grus in the bird family, source: references

Most members of the order Gruiformes are carnivorous birds, but in Europe during the Eocene and Oligocene periods, the Strigogyps of the family Aristornis was proven to be a herbivorous wonder, and its size was also very small, only about the size of a crested pheasant.

Owl, source: Deviantart

On the other side of the Eurasian continent, in China, there was also a prehistoric crane species in the earlier Palaeocene, which was the Qianshanornis found in Anhui . Its second toe was upturned like prehistoric dromaeosaurs and modern cranes, and its specialized claws facilitated the control of struggling prey. Although the forelimbs of Qianshanornis are not well preserved, its condyle shows that its flying ability was better than that of modern cranes.

Hidden mountain bird, Image source: Nix Illustration

Paleogeographical research shows that for a long time in the modern era, there was a vague island chain between Africa and South America, allowing species from the two continents to spread across the continent through the "island-hopping strategy." In Algeria in the Middle Eocene, there lived Lavocatavis africana, which was suspected to be a crane. Only an almost complete right femur fossil was found.

Lasniopteryx (left) and prehistoric giant hyrax (right), Image source: Nix Illustration

Because of the incompleteness of its fossils, it is hard to say whether it belongs to the order Grus! In addition, there is another famous evolutionary branch of the order Grus in North America - the Bathornithidae. Although there are some species with bodies as tall as adults, their beaks are generally small and their ecological niche is relatively marginal.

Several non-terror bird families were called Gruiformes in the early days, including 1 and 7 high bird families, source: Deviantart

It should be pointed out that although birds are the orthodox sequels of dinosaurs, they do not have the spirit of the originals at all, which is a bit "forgetful of their ancestors". They have lost the sharp teeth, claws and strong tails that their dinosaur ancestors were proud of. They are far less competitive on land than mammals and have been driven into the sky. Around the end of the Oligocene, due to climate change and the strong rise of predatory mammals, all cranes on other continents except their base in South America became extinct.

Their legacy was inherited by the famous terror bird family (Phorusrhacidae)!

Terror Bird

Terror bird is translated from its English common name terror bird. Due to inaccurate translation in the early years, terror bird was often confused with the extinct large flightless herbivorous bird Dinornithidae of New Zealand in popular culture.

Representative species of the family of terror birds, source: Deviantart

At the beginning of the Cenozoic Era, there had just been a major reshuffle, and large carnivorous mammals had not yet fully emerged. In addition, due to geographical barriers, South America, which was isolated overseas, had the best time and place.

Terror birds and crocodiles took the lead in filling the gap, evolving into the kings that dominated the local top ecological niche and becoming a "separatist force" that dominated one side.

Excluding the Brontornithinae, which is controversial in its classification and may be duck-like, the Terror Bird family currently includes a total of four subfamilies: the light and flexible Psilopterinae and Mesembriornithinae; as well as the tall, strong-beaked Terror Birds Phorusrhacinae and Patagonithinae that can hunt larger prey.

Let's talk about the first two categories first. The subfamily of Gnathosperminae includes four genera. It is a type of terror bird that is the smallest in size, but has the longest life span and is the last to become extinct [surviving until about 10,000 to 30,000 years ago]. Its appearance is very similar to the two cranes today. The model genus Gnathospermia appeared in the Oligocene and finally became extinct in the Pleistocene. It can be said that it is "dancing" on the grave of the former large terror birds!

In the middle and late Pleistocene, other terror birds had become extinct, but the naked-winged bird still survived. Image source: Deviantart

The subfamily Mesembriornis includes two moderately sized genera, of which the magnificent bird is the most complete fossil member of the family so far, providing important reference value for further research on the survival habits of the family. Another member of the subfamily, the southern monster bird (Mesembriornis), has slender legs and is good at running. Some studies even believe that it can reach a speed of 97 km/h, which is equivalent to a "cheetah" in its environment.

Fossils of the magnificent bird (left) and restoration (right), source: Wiki, Facebook

The remaining two terror birds of the subfamily are called "true terror birds", which are the most classic terror birds in the traditional sense, with tall bodies and thick beaks. Although Andalgalornis of the Patagonian subfamily is relatively unknown, with a medium body and a height of only 1.4 meters, it has been found to have a relatively complete skull, and many terror bird fossils are "headless cases", so it has become the "hardworking face replacement".

Modeling and restoration of the skull of the Andalgara terror bird, source: National Geographi

The last subfamily of terror birds is the ultimate killer of the entire family. It can hunt animals larger than itself and is one of the top predators in its animal group. The head of the terror bird family is the earliest surviving bird of the subfamily, Phorusrhacos, which lived in the early and middle Miocene. It is also the first terror bird to be discovered and named, dating back to the second half of the 19th century. Its skull can be up to 65 cm long, about 2.4-2.7 meters high, and weigh up to 130 kg, which is comparable to the living ostrich.

Curved-belted Terrorbird, Image source: Reddit

Although the spur-shaped terror bird is the head of the family, it is far from the strongest terror bird. This title should belong to the Kelenken. It is the largest terror bird, with an estimated height of nearly 3 meters and a weight of more than 200 kilograms. More importantly, it has the largest skull among known birds, with a length of 70 centimeters. It is relatively strong overall and can withstand pressure from all directions. The huge size and powerful hardware made it a terrifying existence for almost all creatures in South America at that time!

Carlincken Terror Bird, source: Twitter

Devincenzia, which lived from the late Miocene to the early Pliocene, looked like a stouter version of the Devincenzia and was the largest predator in the group.

Devonshire Terror Bird, source: Twitter

Although the last Titanosaurus may be the smallest member of the subfamily, it is the last member to survive and the only one to survive to the Pleistocene (about 1.8 million years ago), and its appearance rate in the mass media far exceeds that of its peers. Despite its fame, the completeness of its fossils can only be described as "residues". It is also the only terror bird with fossil records in North America (limited to the southern states of the United States).

The Titanosaur encountered a slender saber-toothed tiger while heading north. Image source: Facebook

The end of the dynasty

The diversity of the family of Terrorbirds began to increase in the Oligocene and reached its peak in the Miocene, with most species coexisting in the Miocene.

Even until the end of the Miocene, there were once coexisting Devonson's Terror Bird, which was taller than humans, Southern Terror Bird, which weighed about 70 kg, Andalgarra Terror Bird, which weighed 40 kg, and Magnificent Terror Bird, which weighed less than 20 kg, Procariama and Naked-winged Bird in southern South America . With such strong diversity, there was no sign of decline.

Iconic terror birds of the Miocene. Image source: Twitter

In the past, the reason for the decline of the terror birds was often attributed to the loss of competition with the northern eutherians. However, the last two large terror birds survived until the great exchange of species between North and South America. Among them, the Titan Terror Bird took up the banner of the Northern Expedition and entered the enemy's territory in a mighty manner, and even fought back and forth. More importantly, the time when the northern eutherians entered South America seems to be later than the time when the terror birds declined completely. There must be a hidden reason!

It is undeniable that not only the terror birds, but other native species in South America, whether it is the South American marsupials or the South American ungulates, almost all declined rapidly shortly after entering the Pliocene .

The ecosystem is a huge and widely connected whole. The extinction of some groups will inevitably affect the survival of other groups. The most likely explanation is that the natural environment in South America was undergoing drastic changes at that time.

In the Chapadmalal Formation in southern South America, archaeologists have also discovered traces of meteorite impacts. The sudden natural disaster has put the already precarious animal population even more in jeopardy.

As the most specialized branch of theropod dinosaurs, birds are still active in every corner of the earth today, and their population ranks first among terrestrial vertebrates, far surpassing that of mammals. They have explored different ecological niches in the sky, underground and in the sea, becoming the most evolved representative of the Sauropoda.

Recent footprint fossils show that even large terror birds have a raised second toe like their close relatives, cranes. Image source: References

Although the existing flightless birds are all docile herbivores and are no longer comparable to the terror birds in terms of ecological niche, the terror birds' attempts to return to land and compete for dominant dominance and the glorious history they created are enough to be remembered.

References:

[1] First terror bird footprints reveal functionally didactyl posture

[2] Gerald Mayr, Exceptionally preserved plant parenchyma in the digestive tract indicates a herbivorous diet in the Middle Eocene bird Strigogyps sapea (Ameghinornithidae)

[3] Mayr, G.; Yang, J.; De Bast, E.; Li, C.-S.; Smith, T. A Strigogyps-like bird from the middle Paleocene of China with an unusual grasping foot. Journal of Vertebrate Paleontology. 2013-06-25, 33 (4): 895–901.

[4] Cécile Mourer-Chauviré; Rodolphe Tabuce; ​​M'hammed Mahboubi; Mohammed Adaci; Mustapha Bensalah. A phororhacoid bird from the Eocene of Africa. Naturwissenschaften. 2011, 98 (10): 815–823.

[5] "Prehistoric Park ◎1" Giant Birds Galloping: A Brief History of the Rise and Fall of Terror Birds

[6] Nowak, Ronald M. (2005). "Cheetah Acinonyx jubatus". Walker's carnivores of the world. Baltimore: Johns Hopkins University Press.

[7] Chauviré, Tabuce, Mahboubi, Mohammed (2011) A Phororhacoid bird from the Eocene of Africa

Author: Xie Honghan, popular science author

Editor: Guru