When Flightless Birds Ruled the Land: The “Terror” Birds of the New World

A "Terror Bird" Titanis walleri, Florida Museum of Natural History. A giant bird that once roamed florida.  Image credit: Wikipedia
A “Terror Bird,” Titanis walleri,  on display at the Florida Museum of Natural History. This “small” terror bird was endemic to North America and is best known from fossils from Florida. Image credit: Wikipedia

Dinosaurs and large mammals, like mammoths, get all the attention, but the fossil record is full of amazing animals from ages past that haven’t yet been brought to the public eye through a Pixar movie.  Such is the case of the so-called “terror birds” of South America. The terror birds are a group of birds known only from fossils. These fossils have been classified in 14 genera and 18 described species in a single family, the Phorusrhacidae.   

All terror bird fossils are found in the upper portion of the geological column spanning the layers that conventional geologists date from 62 to just 2 million years ago.  There is no evidence that a terror bird ever met a dinosaur since all dinosaur fossils are found in sedimentary rocks below those which contain terror birds.  Likewise there is not evidence that terror birds ever had any encounters with man. 

All terror birds were flightless with over-sized beaks. Several species were so large that they represent the largest birds to have ever been discovered. The terror birds had wings, but they were very small in relationship to the body, just as the T. rex had small arms relative to its body.  You can think of them as really scary-looking ostriches.

Relative sizes of two of the largest terror birds and the largest known birds to have ever lived.  There may have been extinct moas from New Zealand that were taller but were probably not large overall.
Titanis Walleri, fossilized Terror bird skull.  Image: Scientific American, February 1994.
Fossilized terror bird skull.  Larger ones have been found in the past couple of years.  Image: Scientific American, February 1994.

Many species of terror birds would have towered over the tallest man and it appears that they were either scavengers or actively caught mammals, possibly the size of goats and sheep, reptiles and other birds for food.  When these birds lived in South America, there just a few other predators such as the strange carnivorous metatherian mammals called the Sparassodonta, which are also all extinct. Whether the terror birds were active predators or not is not well established but they must have been an imposing presence in South America.  

Thylacomilus, an extinct carnivorous animals from South America along with the huge armadillo-type organism called a Gyptodont. The former looks like a saber-tooth cat but is not related. Rather this is a Sparassodont which is an extinct order of carnivorous metatherian mammals native to South America. These are neither marsupials (like kangaroos) or placentals (like most living mammals). Image credit:  Deur Rom-diz – Eie werk, Publieke domein, https://commons.wikimedia.org/w/index.php?curid=10963980

Terror bird fossils are found throughout South America, but remains of one species has been found in North America.  This single large (4 to 6-foot tall) species was found in Florida. It is very difficult to imagine what it would have been like to observe groups of 6-foot birds roaming the scrub plains of Florida hunting animals.  Although it would have been awesome to see one of these from afar, encountering a bird more than 6-feet tall with a head the size of horse would have been scary.  One can’t help but notice from the skeletons that these birds are quite reminiscent of several lineages of theropod dinosaurs including Tyrannosaurus rex.

Where do these birds fit in the creationist timeline?

The Red-legged Seriema. A possible relative of the terror birds.  This is all that is left after the invasion of South America by canines and cats (leopards) probably brought an end to the large flightless birds. Image: Wikipedia.
The Red-legged Seriema. A possible living relative of the terror birds. This is all that is left after the invasion of South America by canines and cats (leopards) probably brought an end to the large flightless birds. Image: Wikipedia.

These must have been very distinct birds. If they were living on Earth only a few thousand years ago–a necessity in the young-earth chronology–one would expect to have eyewitness reports.  We have already seen how the author of Job references the ostrich and other contemporary animals. Had terror birds been known in that part of the world, one would imagine that God would have used them as an example to Job of his creation.  But alas, the only evidence we have of their existence is found in fossil bones. And with no evidence of their fossils existing alongside hominid fossils, the terror birds seem to belong to a world from long before man walked the earth.

Young-earth creationists believe that representatives of each bird “kind”–roughly equivalent to the taxonomic grouping of family–were preserved on Noah’s ark and then entered, from the Ark’s resting place in the Middle East, a world devoid of living land animals less than 4500 years ago.

The Ark Encounter themed attraction in Kentucky, operated by the young-earth apologetic ministry Answers in Genesis (AiG) lists all of the supposed “kinds” of animals that they believe Noah took with him on the ark.  That list includes terror birds, but condenses all species of them into one “kind” of now-extinct bird. AiG lists the family Phorusrhacidae as being on the ark, indicating they believe that there was just one pair of terror bird representatives on the Ark.   

The first bird (A) is living but the rest are various species of terror birds all of which are extinct. “Reconstructions of some phorusrhacids compared to the extant Cariama. (A) Cariama cristata; (B) Mesembriornis milneedwardsi; (C) Psilopterus bachmanni; (D) Andalgalornis steuletti; (E) Phorusrhacus longissimus; (F) Paraphysornis brasiliensis; and (G) Brontornis burmeiteri. A man’s silhouette (1.75 m) is used as scale. (Drawing by Eduardo Brettas.)” From: ‘Living dinosaurs : the evolutionary history of modern birds’ edited by Gareth Dyke and Gary Kaiser.

Just like the ostriches, penguins and rheas—but, notably, not the flightless great auks!—the terror birds survived the global flood and were then released from Noah’s Ark in the Middle East.  Young-earth creationists are now left with a great mystery! How did a pair of flightless terror birds travel all the way to South America, leaving no evidence of their existence in the Old World, evolve into a dozen distinct species, all of which went extinct and yet are well-represented in the fossil record, and do all of this, before man arrived, just a few hundred years after departing Noah’s ark? If multiple species of terror birds were distributed over South America and even parts of North America, why is there is no evidence that any Native American ever encountered these flightless birds?  They should have made for some good eating, much as the moa did in New Zealand in the 1400s.

As we have documented in many other examples, the super-fast evolution that young-earth creationists advocate doesn’t make sense in light of genetics, geographical distribution, written historical record or the fossil record. The young-earth timeline strains credulity in every way.

Having read a draft of this article a friend summarized it this way:

“AiG would have us believe that that the laws of physics and genetics were radically altered due to the fall of man and the great flood. But what of every other scientific discipline? According to the young-earth timeline and teaching, these terror birds, in only a couple hundred years, migrated to another continent while leaving no evidence of their existence elsewhere, evolved into at least 18 different species found on two continents, and went extinct without any evidence of ever interacting with human beings. Surely such improbable events would be supported by some evidence! But, no. This wildly unlikely story is merely a product of necessity, forced like a square peg into a round hole. The young-earth insistence upon a literal seven-day creation and a six to ten-thousand year old universe leaves no alternative than to compress events like these and to manufacture “explanations” that, rather than matching hand in glove with the evidence, instead perfectly match their own theology and ignore the evidence altogether.”

Other posts in this series:

Consider the Ostrich: Job 39 and God’s Commentary on His Creation
Consider the Ostrich: Comparing Theistic Models of Biological Origins
The Prelapsarian Ostrich: Paradise Lost of a Portrait of a Good Creation?
Consider the Ostrich: Literal-Day Creationists Unsure about the Ostrich’s Created Condition

This article is an updated version of one first published in March 2013.
Editing graciously provided by MC.

16 thoughts on “When Flightless Birds Ruled the Land: The “Terror” Birds of the New World

  1. Sou Evolucionista, Neodarwinista! O ambiente seleciona as espécies mais aptas em detrimento das menos aptas e fatores como as mutações (gênicas e aberrações) e a própria recombinação gênica (Prófase I – Paquíteno ou Paquinema da Meiose I) são os fatores geradores da viariabilidade sobre a qual atua o processo de seleção sempre que uma população se encontra em isolamento reprodutivo, cujas causas podem ser as mais diversas possíveis!


    1. My Google translator doesn’t seem to be handling the Portuguese all that well but I think I agree. My story about selection is mostly a story about possibly environmental influences on the direction of selection. I don’t think we have a strong enough fossil record of these birds to know if they evolved from smaller flighted birds or if they may have inherited their stature from large ancestors that may never have been good at flight. Lots of unknowns but the diversity of fossils does suggest the birds filled a lot of niches in South America while predatory competition was low.


    1. Not an uncommon question. Check out my “about page” for more but essentially, my target audience are creationists. As a Christian who is not a young earth creationists I have a passion for demonstrating that what we learn from the nature does not fit with a young earth creationist view of the world. I could write a story (and do at times) that just tells the science story but I want my particular target audience to see how the science relates to their views and makes them think about them.


  2. Hi there,
    If you really want to make some kind of creationnist critique, maybe you could ask how these birds would have survived in such a confined place as Noah’s ark without driving to extinction many small mammal and bird species, and maybe even Noah himself. That would hold for virtually all predators…


  3. The genetics of the Cyclids of Lake Victoria demonstrate high Speed Evolution is possible. At least 500 species of Cyclids evolved within a mere 14 thousand years, and even in shorter time spans is a seperated lake. All biological niches occupied. Adaptation and Speciation are built-in traits of created kinds and we can now see how it works. It is explained by genetic assimilation and frontloaded genetic systems.

    Click to access j22_2_79-84.pdf

    Click to access j22_3_68-76.pdf

    Click to access j23_1_99-106.pdf

    Click to access j23_1_107-114.pdf


    1. Sure, speciation can happen quickly in some circumstances but this is hardly comparible to speciation of canines or felids or especially elephants with far longer life cycles. However, even 14,000 years though is way too long for YECs who need to push that speciation into a few hundred years after the Flood. But one also needs an apples to apples comparison. How much total genetic divergence has occurred among the Cyclids? Barely any. If you compared the genome of two Lake Victoria Cyclids with the genome of a fox vs a coyote would they exhibit similar amounts of genetic divergence? You would not be wrong to guess no. Cyclids experience selection at a few genetic loci but their genomes are very very similar to each other.

      Liked by 1 person

  4. If you manage to find it, walking with bests – the excellent sequel to the excellent-er walking with dinosaurs – has a good terrorbird episode.

    Also, one of the old trackbacks has a critique of your article. Did you ever respond?


    1. Thanks for pointing that out to me. I don’t think I looked at that article but now that I have I will respond. My updated version has changed quite a bit and addresses some of the problems including the acknowledgement that many (probably most now) think that God just make flightless birds flightless. Of course that raised a number of other questions which I have addressed in my ostrich series.


  5. While most phorusrhachids are South American, Titanis has been found in Texas, thus far, the only one not in South America of which I am aware. Also, recent work has put Brontornis as related to the Gastornithids, another group of giant flightless birds that are often confused with the phorusrhachids, but with a worldwide distribution. If YECs do not accept the distinction between the two groups, which they could make a case for if arguing from superficial similarities and ignoring numerous details, they won’t accept your argument either. They will simply say that of course they left evidence across the world. There are all these other types of giant flightless birds that scientists incorrectly attribute to different groups and refuse to recognize they are all the same to support their anti-biblical agenda. Please note, I am NOT saying they are right, because they are not, but I am expecting this is the argument they will use.


    1. Thanks for the update. This is just what some will say I am sure. . However, I just looked at the information on the Ark Encounter and they list the Gastornithidae as a separate created kind so one can always point to that as the leading YEC organization saying that they are unrelated. I may want to append a note about this to the article just to ward off that response.


  6. Terror birds also existed in what is now Germany. They have been unearthed in Messel. Usually, the German location is not mentioned, since it is unexplained in the current longe ages paradigm.


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