One of the strangest predators the world has ever known. An awesome group of native predators, a 10–foot–tall, flightless, killer bird: called Phorusrhacos, a group of flesh-eating birds aptly nicknamed "Terror Birds". These vicious carnivores use their heavy beaks to batter obstacles and tear flesh, and left little of their victims intact. Flightless birds, these 10-foot-tall predators could none the less run 65 km/h – making them rather difficult to take care of.
— Allen, describing Phorusrhacos
Phorusrhacos (name meaning "Rag-Bearer"), commonly known as the Terror Bird, is a genus of large, carnivorous, flightless terror bird that originated during the Early Miocene in what is now Nort and South America. Standing around 3 meters tall, Phorusrhacos was the largest flightless bird of all time and one of the top predators of its region until other predators from North America, such as Smilodon, migrated to South America. 

In the episode "Saving the Saber-Tooth“, a breeding pair of Phorusrhacos were brought back to the park from Early Pleistocene South America 1 million years ago. 


Era & DiscoveryEdit

Phorusrhacos lived during the Early Miocene and Late Pleistocene period, from 20 million to 13,000 years ago. These creatures evolved when South America was an isolated continent. It was the top predator of South America for millions of years, unchallenged by any other predator. However, as the land bridge formed between North and South America, Sabre-Toothed Cats, such as Smilodon, invaded, shifting the balance of power. Therefore, Smilodon outcompeted the birds as top predators.

South America wasn't the only place these Terror Birds were doing well. Once the land bridge opened to North America, Phorusrhacos was one of the few creatures to spread north successfully. While the Terror Birds in South America eat Smilodons leftovers, their cousins were running riot in Texas and Florida. They only died out just before modern humans appeared.

A recent discovery of a close relative in North America suggests that they also had claws on their wings, which is unusual, although it is not clear how these would have been used. Among the bones found in the strata of the Santa Cruz Formation (now considered as mainly of mid-Miocene date) was the piece of a mandible which Florentino Ameghino discovered in early 1887 and, the same year, at first described as that of an edentate mammal, which he named Phorusrhacos longissimus. In 1891, it was recognized to be a bird. Remains are known from several localities in the Santa Cruz Province, of Argentina.

Physical AttributesEdit

  • Male Phorusrhacos
  • Female Phorusrhacos

The largest flightless bird of all time, Phorusrhacos was a member of a lineage of carnivorous flightless birds commonly nicknamed "terror birds". This name is derived from their metabolism and weapons. Standing over 10 feet (3 m) tall and weighing approximately 130 kilograms (280 lbs.), these magnificent creatures was the largest and tallest of the lineage.

Phorusrhacos was a large, carnivorous but lightly-built bird. It possessed a large, fearsome beak which was hooked at the tip, like a modern eagle. At the top of its head was a small plumage of feathers. This bird, since it was flightless, had only small wings that rendered them unable to lift it into the air. However, unlike most modern birds, it possessed a sharp claw on the wings, making them into potential weapons against prey and rivals.

The legs of Phorusrhacos were skinny and long. On its feet were sharp talons. In addition, Phorusrhacos males and females were different in appearance and size. The males had a white neck and underbelly and the rest of their feathers were brown. Their beaks and legs were a vivid red color. They also had some black display feathers on its head. The females were more yellowish and had a black stripe coming down their bodies from their eyes. Like the males, they had a display of feathers on their heads, but theirs was smaller.

These birds were agile and in need of regular kills. Its most lethal and formidable weapon was its large beak. It was an imposing killer, with an eagle-like hooked beak, for tearing into mammalian prey. Unlike modern flightless birds like ostriches, its head and beak were large. At the end of its beak was a sharp hook, similar to that of modern birds of prey. This deadly weapon was most likely used to puncture the head of its prey and to cause major brain damage. The shock of the impact would instantly kill it. 

They had sharp talons on their thick scaled feet, and their legs were very slim and elegantly tall. They would have been able to run at incredible speeds, faster even than a horse at the races at full pelt (due to the immense stride lengths and efficient bird heart, like an Ostrich or even a dinosaur). In fact, Phorusrachos would have looked for all the world like a theropod dinosaur covered in smooth feathers. It would have had glaring, scary eyes, like any bird of prey has similarly. 

Behavior & TraitsEdit

Phorusrhacos were not pushovers, even for Smilodon. What is more, they could have hunted in packs or at least pairs, and on one to one, the biggest Phorusrhacos were more than a match for any Smilodon. The simple truth is these became joint shareholders of the top predator niche - and would likely have just tried to avoid each other whenever and wherever possible.

The deadly Terror Birds, to prove this claim, we know to have moved north into the plains of Texas and Florida - where they terrorized the ancient horses, and became known to some experts as a new species, called Titanis (this is not now accepted in the best circles of Palaeontology, as it seems it was still just Phorusrhacos).



  • Phorusrhacos is the last and largest prehistoric flightless bird brought to the park.
  • The sound effects of Phorusrhacos are that of hawk, ostrich, and vulture sound effects.
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