Raven, the claw-handed bird, last of the phorusrhacids

i-2cf58dc4ff6419aca52f869df24b08ed-Titanis walleri claw-handed good recon.jpg

As if the revelations about Brontornis and all that new work on the ameghinornithids weren't enough, 2007 also saw the publication of a long-awaited new study on the age of Titanis walleri, North America's only phorusrhacid, and - supposedly - a species that survived until as recently as 15,000 years ago. Yes, it's time to crack on with more terror birds, or phorusrhacids. It's a story of ancient island-hopping, of the proposed re-evolution of clawed forelimbs, and of Raven, the giant claw-handed bird of Native American folklore...

Titanis walleri Brodkorb, 1963 is one of the largest and last of the phorusrhacids, and after its 1961 discovery near the Sante Fe River in Florida (Brodkorb 1963), additional remains referred to the species were reported from three other Floridan localities as well as from Texas. As of 2005, Titanis was known from 41 separate elements including several skull fragments, some vertebrae, assorted pectoral and forelimb bones, and femoral shafts and other hindlimb fragments, including multiple isolated phalanges (Gould & Quitmyer 2005). Some of the Sante Fe material was discovered by diving, as the fossils actually occur on the river bottom. Unfortunately none of this material is articulated, and the reconstructions of Titanis that you can see in museums (the Florida Museum of Natural History is home to a mounted skeleton: it's shown below) and in the literature are based on more complete skeletons of other phorusrhacids. It is assumed that Titanis was a phorusrhacine phorusrhacid, so it's often modelled on what we know of taxa like Devincenzia. However, phorusrhacine affinities are not certain for Titanis and it actually resembled mesembriornithines in tarsometatarsal morphology (Alvarenga & Höfling 2003) [I don't know who did the excellent restoration used above; it's available widely online. Looks like one of Carl's].

Two exciting proposals

i-02eecff63f3240fd1d147372dc4aa5bf-J. Gage Titanis recon.jpg

Two key recent claims have made Titanis one of the most famous and most discussed of all fossil birds. The first is that, rather than possessing stunted, redundant little wings that were effectively functionless (bar possible, and unknown, uses in display, intraspecific combat or in assisting balance), Titanis actually sported semi-prehensile, clawed hands that probably functioned in predation. The second is that Titanis survived until far more recently than all of its South American cousins, and persisted into the Pleistocene and even well into the Late Pleistocene (a possible Pleistocene phorusrhacine was reported from Uruguay by Tambussi et al. (1999), but if it is Pleistocene and not Pliocene it can only be Early Pleistocene). Let's think about both of these proposals for a minute. If Titanis actually had clawed, mobile fingers, then most of the classic stuff written about phorusrhacid behaviour and habits (e.g., Marshall 1994) could very well be completely wrong, as rather than relying on their hindlimbs and/or massive bill to procure and process prey, this discovery would suggest that manual apprehension and manipulation played a significant role in phorusrhacid predatory behaviour. This is radical and might have made Titanis (and perhaps all phorusrhacines, or even all phorusrhacids) superficially like Cretaceous non-avian maniraptorans, like dromaeosaurs. This extremely appealing idea was not lost on some (Zimmer 1997).

Secondly, if Titanis was still extant as recently as the Late Pleistocene (perhaps as recently as 15,000 years ago), then there's the possibility that something very interesting happened. Namely, that people saw this amazing animal.... if, that is, people were present in south-eastern North America this early (and they were: e.g., Goebel et al. 2008). A giant predatory flightless bird, over 1.5 m tall (Titanis has been down-sized in recent years), with a massive hooked bill and the ability to knock down and eviscerate even quite large mammals would probably leave quite an impression on the imagination, to say the least. Might there be any Native American folklore, mythology or artwork hinting at ancient knowledge of this giant bird? According to Jaroslav Mareš's 1997 book Svet Tajemných Zvířat, maybe there is, because both the Kwakiutl and Haida people had stories of Raven, a 'monstrous giant bird with a massive hooked beak, long sturdy legs .... and a feathered body - but possessing front paws with claws, instead of wings!' (Shuker 2003: I haven't seen Mareš's book).

Understandably, it's been very tempting to suggest that the Kwakiutl and Haida people might perhaps have encountered Titanis, thereby explaining the origins of Raven. However, all is not well with this idea. The Kwakiutl (who are, wikipedia tells me, properly known as the Kwakwaka'wakw) and Haida are not from the southern US, but from British Columbia and elsewhere on the Pacific coast - not exactly in the right place to see a bird that (so far as we know) didn't live any further north than central Florida. This all suggests to me that linking Raven with Titanis was, unfortunately, a mistake. In any case, other evidence has now come along that also destroys what is an otherwise fine hypothesis.

No prehensile clawed hands for you, Titanis

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The idea that Titanis had unusual hands was proposed by Robert Chandler who described new wing material (a partial humerus and a carpometacarpus) discovered around the banks of the Sante Fe. Chandler (1994) proposed that the strong, robust humerus of Titanis suggested that its wings were powerful organs, and not weak, vestigial ones. He also argued that Titanis had stiff wrists which resulted in the hands being held in line with the forearms (as is the case in, for example, penguins), and - most importantly - that a large ball joint on the carpometacarpus indicated the presence of a flexible thumb equipped with a claw. Reconstructions based on Chandler's work (Zimmer 1997) also equip the phorusrhacid hand with a large claw on the end of digit II. It is these observations which resulted in the idea that Titanis had prehensile, clawed hands... but, things don't quite follow here [as you can see from the accompanying life restoration, some people unfortunately took the 'prehensile hands' thing all too literally!].

Titanis did apparently have a relatively rigid wrist. However, the ball joint of the Titanis carpometacarpus is actually nothing special as the same sort of joint is present in seriemas (Gould & Quitmyer 2005). It does not indicate the presence of a large flexible thumb with a big claw, it merely shows that the alular digit was mobile (of course, this digit is mobile in all birds, but they don't all have a convex articular facet on the carpometacarpus - it is usually flat)*. The alular digit of Titanis is unknown, so any ideas about big claws are entirely speculative. Similarly, the idea that digit II sported a big claw is also totally speculative as the phalanges of the hand are totally unknown! Given that claws on digits I and II are actually not uncommon in birds, it's still possible that phorusrhacids had them. However, there's no reason to think that they were hypertrophied, nor is there evidence that they were large or had a special function [image below, from Alveranga & Höfling (2003), shows assorted phorusrhacid and other bird carpometacarpi. Titanis, with its large, ball-like articular facet, is A, Cariama is F].

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So, alas, the idea that phorusrhacids were unique among birds in having prehensile, clawed forelimbs has fallen by the wayside and was never based on good evidence. Does the apparently robust humerus suggest any special function for the wing? We don't know, but what data we have shows that the wings of Titanis were not large or unusual in any other way (Gould & Quitmyer 2005). As with so many cool ideas, I will admit that many of us (myself included) promoted the whole 'prehensile hand' thing mainly because it was just so awesome.

* Incidentally, the alular digit almost certainly corresponds with digit I (the pollex) - see Vargas & Fallon (2005) - despite arguments from some corners stating that it must represent digit II.

Was Titanis really alive in the Late Pleistocene?

The idea that people encountered Titanis rests on the assumption that Titanis really was contemporaneous with people: in other words that it made it into the Late Pleistocene. Did Titanis really manage to hang on this late? We need to look at a few things before answering this.

Given that all phorusrhacids are either Antarctican or South American (undescribed Eocene fragments from North America and Europe notwithstanding), Titanis (or an unknown ancestor) must have travelled northwards to get to Texas and Florida. It's conventionally been thought that this could only have happened following the formation of the Panamanian isthmus during the Pliocene (4.5-3.5 million years ago, or thereabouts). Ergo, Titanis fossils must be no older than Early Pliocene, and perhaps much younger.

In Florida, the type material of Titanis from near the Sante Fe River was found associated with Late Pleistocene birds and mammals, including the pampathere Holmesina septentrionalis, the sloth Megalonyx jeffersonii, bison, mammoths, dire wolves and lions (MacFadden et al. 2007), and it was on the basis of this associated fauna that a Late Pleistocene age was first proposed (Brodkorb 1963). However, the same locality also yields an assemblage of Late Pliocene mammals that include the pampathere H. floridanus, the sloth M. leptostomus, the hyaena Chasmaporthetes, borophagines, llamas, pronghorns and three-toed horses. So is the Sante Fe Titanis material Late Pliocene or Late Pleistocene in age?

i-4bc63c83a97ef1a6e69b36a8686e93f0-Titanis phalanx from Baskin site.jpg

Baskin (1995) reported phorusrhacid material from south Texas. Although consisting of but a single pedal phalanx [shown here: from Jon Baskin's site], its strong similarity to the holotype pedal phalanx of T. walleri led him to refer the Texan specimen to that species. Occurring alongside this new bone were both Early Pliocene horses and Late Pleistocene mammoths, bison and other fossils (the fossils appear to have been mixed after the Pliocene elements were washed in from a different locality 15-25 km away). So was the Titanis fossil Early Pliocene or Late Pleistocene? Baskin (1995) concluded that the Titanis bone couldn't go together with the Pliocene fossils, because their Early Pliocene age meant that they pre-dated the formation of the Panamanian isthmus. It must, he concluded, therefore be Late Pleistocene like the mammoths and bison from the site. He also noted that the Titanis bone was more similar in colour to the Pleistocene bones than to the Pliocene ones.

Clearly, any conclusions about the age of Titanis, based on the associated fauna, are, well, inconclusive. To resolve this controversy, MacFadden et al. (2007) used rare earth element (REE) analysis to date the Titanis bones. REEs occur in low abundance in living animals, but during diagenesis are rapidly taken up and concentrated. Different REE concentrations have proved to be reliable signatures of specific local conditions and, among collections of bones that come from mixed sources, REE concentrations can therefore be used to show which bones originated from the same geological environment.

What did the data reveal? That both the Floridan and Texan Titanis material is identical in REE composition to the Pliocene fossils from the same sites, with the Texan material being Early Pliocene and hence about 5 million years old, and the Floridan material being Late Pliocene and hence about 2.2-1.8 million years old (MacFadden et al. 2007) [I first learnt of this while writing the ver 1 phorusrhacids article here, and it explains the 'cough cough' used in the first line]. So, there endeth the idea that Titanis made it all the way to the Late Pleistocene, or even into the Pleistocene at all... at least, so far as we can tell based on present data, of course. But if - as the REE data shows - Titanis was in North America 5 million years ago, and hence prior to the completion of the Panamanian isthmus (which occurred c. 4.5-3.5 million years ago), how on earth did it get there? [replica Titanis skull shown below. As discussed previously, reconstructions like this probably make the rostrum too deep].

i-8c81aae9f064181d027e01e241c8cf19-Titanis replica skull.jpg

The answer seems to be that faunal interchange between North and South America was more complex, and more drawn out, than conventionally thought. Exchange didn't only occur after the land-bridge was complete, but occurred prior to this during the very earliest Pliocene and even Late Miocene. We know that some sloths made the crossing prior to the formation of the land-bridge, for example (previously discussed on Tet Zoo here), as did certain mastodonts, tapirs and raccoons, and it now seems that phorusrhacids did too. These animals presumably island-hopped, but they might also have done a lot of swimming in order to complete the crossing. Notably, sloths and proboscideans are reasonably good long-distance swimmers... were phorusrhacids too? Large extant flightless birds like cassowaries are reported to be strong swimmers.

Phorusrhacids at Tet Zoo: there and back, again and again

With the ending of this article, Tetrapod Zoology is now (probably) the largest repository of publicly-available phorusrhacid information, with the exception of Alveranga & Höfling's open-access review of the group (available for free here). And of course, once Phorusrhacid Bibliography is up and running, even more information on these birds will be out there. In order to have all the Tet Zoo phorusrhacid articles linked to in one place (partly for my own convenience), here is a list...

-- Terror birds (Oct' 27th 2006: general introduction to phorusrhacid diversity and classification)
-- More on phorusrhacids: the biggest, the fastest, the mostest out-of-placest (Nov' 1st 2006: on brontornithines and phorusrhacid palaeobiology in general)
-- Giant hoatzins of doom (Nov' 3rd 2006: on South American landbird hypothesis)
-- Goodbye my giant predatory, cursorial, flightless hoatzin (Nov' 12 2006: on affinites of Cariamae)
-- 2007: a good year for terror birds and mega-ducks (June 10th 2008: on Brontornis and Kelenken)
-- You're not a proto-phorusrhacid, but you're still a cariamaen, and that's alright with me (ode to the Ameghinornithidae) (June 13th 2008: on ameghinornithids)

Finally, thanks to Tommy Tyrberg for sending the Gould & Quitmyer (2005) article: I couldn't get it via inter-library loan. What's next? Well...

Refs - -

Alveranga, H. M. F. & Höfling, E. 2003. Systematic revision of the Phorusrhacidae (Aves: Ralliformes). Papéis Avulsos de Zoologia, Museu de Zoologia da Universidade de São Paulo 43, 55-91.

Baskin, J. A. 1995. The giant flightless bird Titanis walleri (Aves: Phorusrhacidae) from the Pleistocene coastal plain of south Texas. Journal of Vertebrate Paleontology 15, 842-844.

Brodkorb, P. 1963. A giant flightless bird from the Pleistocene of Florida. The Auk 80, 111-115.

Chandler, R. M. 1994. The wing of Titanis walleri (Aves: Phorusrhacidae) from the Late Blancan of Florida. Bulletin of the Florida Museum of Natural History, Biological Sciences 36, 175-180.

Goebel, T., Waters, M. R. & O'Rouke, D. H. 2008. The Late Pleistocene dispersal of modern humans in the Americas. Science 319, 1497-1502.

Gould, G. C. & Quitmyer, I. R. 2005. Titanis walleri: bones of contention. Bulletin of the Florida Museum of Natural History 45, 201-229.

MacFadden, B. J., Labs-Hochstein, J., Hulbert, R. C. & Baskin, J. A. 2007. Revised age of the late Neogene terror bird (Titanis) in North America during the Great American Interchange. Geology 35, 123-126.

Marshall, L. G. 1994. The terror birds of South America. Scientific American 270 (2), 64-69.

Shuker, K. P. N. 2003. The Beasts That Hide From Man. Paraview Press, New York.

Tambussi, C., Ubila, M. & Perea, D. 1999. The youngest large carnassial bird (Phorusrhacidae, Phorusrhacinae) from South America (Pliocene-Early Pleistocene of Uruguay). Journal of Vertebrate Paleontology 19, 404-406.

Vargas, A. O. & Fallon, J. F. 2005. The digits of the wing of birds are 1, 2, and 3. A review. Journal of Experimental Zoology (Mol Dev Evol) 304B, 206-219.

Zimmer, C. 1997. Terror take two. Discover 18 (6), 68-74.


More like this

Actually, given that they've been extinct for quite some time now, 2007 wasn't really a particularly good year for either terror birds, aka phorusrhacids, or for mega-ducks (on which read on), but it was a pretty good year in terms of the new material that was published on them. Phorusrhacids were…
Titanis Walleri, Terror bird. artist's rendering. Image: University of Florida. University of Florida paleontologist Bruce MacFadden said his team has determined that a prehistoric 7 foot tall flightless "terror bird," Titanis walleri, arrived in North America from South America long before a…
Sloths. Were there predatory sloths? Sloths that lived in the sea? Sloths that dug immense tunnels? Sloths on Antarctica? Sloths so keen to get to the US of A that they didn't wait for the land bridge, but swam the way instead? Well, let's see... Today I was asked a question about sloths. Sloths…
You'll recall me saying recently that 2007 was a good year for publications on phorusrhacids, aka terror birds. And as I discussed in the previous post, one of the most interesting contentions made about phorusrhacids last year was that one of the most remarkable members of the group (super-robust…

Totally off the Phorusrhacid topic... I now know what Bruce McFadden looks and sounds like. The AMNH (New York) temporary exhibition "The Horse" (it's in the same gallery as their Liaoning exhibition of a few years back- I don't know whether it is going to go on the road like that exhibit or not) features a video interview with him (on the use of carbon ?isotope? analysis of fossil tooth enamel to determine dietary preferences of extinct equids.
(His textbook on "Fossil Horses" was on sale in the gift shop: $55 paperback.)
Exhibition also featured Shire and Shetland Pony skeletons for comparison, and a lifesize diorama with a Dinohippus, a Nanippus and another 3-toed type side-byside in a landscape where each could nibble its favorite greenery.

By Allen Hazen (not verified) on 18 Jun 2008 #permalink

No clawed forepaws, eh? That's disappointing, as I've always liked the idea. Terror birds are fantastic in general though, so it's not a big deal. I think it's interesting that the "terror bird" body type evolved so often among extinct birds (although not all of them were carnivores).

Is it safe to say that terror birds were the dominant predators in the areas they inhabited? Did they share territory with any large carnivorous mammals, and if so, how did the two groups cohabituate?

But if - as the REE data shows - Titanis was in North America 5 million years ago, and hence prior to the completion of the Panamanian isthmus (which occurred c. 4.5-3.5 million years ago), how on earth did it get there?

It's a bird. It flew. (Duh!)

Oh, a flightless bird, you say? All of them? OK.

I'm thinking turtles, now. Zach, can we get a reconstruction of a young terror bird standing on a sea turtle churning hard north, clawed wing shading its eyes as it gazes resolutely toward the horizon ahead?

By Nathan Myers (not verified) on 18 Jun 2008 #permalink

Nice roundup of the Titanis research, Darren, I'd heard bits and pieces of that but not the Raven story (!).

I'm not convinced that giant flightless birds, or indeed any terrestrial flightless birds, have actually dispersed over any water gap, no matter how small. There's some cassowary dispersal around New Guinea, but I've seen it argued that they were actually traslocated by indigenous New Guineans. Certainly no evidence for moa or kiwi ever swimming to any of the little islands that surround New Zealand.

What does "island hopping" mean, anyway, that swimming doesn't encapsulate? You hear it a lot, but I always think of a long chain of islands a few feet apart, which seems implausible.

Anyone know of flightless birds crossing oceanic barriers?

Aw shucks... no more terror birds with clawed hands like tyrannosaurs? That's a bummer.

Still, hands or no hands, I think they were awesome vicious predators. I just find it a darn shame that they didn't manage to stick around long enough to threaten humans a la 10,000 BC.

Mike: given that phorusrhacids must have made the crossing to North America before the land-bridge formed (it seems), I suppose they must have swam between some of the islands (you're right, 'island hopping' means swimming, just swimming broken up into lots of short distances rather than one continuous one).

As you note, cassowary distribution might indicate over-water dispersal, but this remains unclear because people moved the birds around a lot. There is a report of a kiwi found swimming at sea, some distance from land. This is from memory and I cannot find the reference, but I'm trying to locate it. Emus look to be reasonably good swimmers, and here's a video for evidence. Another video (here) might show emus crossing a river, but not enough is shown to be sure.

Ha - another subject often asserted but sadly lacking in direct observation and testing. This gives me an idea for a paper... (yeah, like I need another one to do).

I've heard the hypothesis (though never read any paper detailing the evidence) that the earliest phase of the Great American Faunal Interchange began when a land bridge emerged from what is now Venezuela, through Trinidad, up to Haiti and Cuba and then through the Bahamas to Florida. This land bridge need not have been continuous all at one time, you just need a connection from South America to say Cuba, followed by a connection from Cuba to mainland NA later, after the original SA connection had severed. This might explain the Floridan and Texan distribution of Titanis. Such an hypothesis should be easily tested. Firstly we would expect to see South American taxa in the Pliocene record of Cuba or Haiti (do we? I don't know) and if the landbridge was not continuous all the time we shpould expect the interchange to be one-way, ie. South American beasties going North but not vice-versa. As I understand it this part of the pattern is observed with early ground sloths, phorusrhacids and such like appearing in the Pliocene of North America with no North American taxa appearing in South America at the same time. An interesting idea even if wrong.

By Adam Yates (not verified) on 18 Jun 2008 #permalink

In Alaska, anyway, Raven doesn't have "clawed forepaws." He can take a human shape or a bird's shape. Northwestern North American mythology is full of characters who can take two forms.

By Jenny Islander (not verified) on 18 Jun 2008 #permalink

"most of the classic stuff written about phorusrhacid behaviour and habits (e.g., Marshall 1994) could very well be completely wrong"

Darren, you missed the best part. Was ANYTHING written about phorusrhacid behaviour (other that they ate meat)?

For example, "Walking With Dinosaurs" tried to present phorusrhacids as scavengers. Seems to me supremely un-adapted for crushing bones.

Adam: a 'pre-land bridge northward dispersal' in the Early Pliocene (c. 4.7-4.8 Ma) is supported on the basis of sloths and other taxa in Mexico (Flynn et al. 2005). This suggests that those animals at least weren't using the Caribbean islands to hop north (also, note that the Floridan Titanis fossils are Late Pliocene and hence younger than the Texan record).

Ref - -

Flynn, J. J., Kowalis, B. J., Nuñez, C., Carranza-Casteñeda, O., Miller, W. E., Swisher, C. C. & Lindsay, E. H. 2005. Geochronology of Hemphilian-Blancan aged strata, Guanajuato, Mexico, and implications for timing of the Great American Biotic Interchange. Journal of Geology 113, 287-307.

> Is it safe to say that terror birds were the dominant predators in
> the areas they inhabited? Did they share territory with any large
> carnivorous mammals, and if so, how did the two groups cohabituate?


they did share territory with the marsupial sparassodonts in SA (some of them, like saber-toothed *Thylacosmilus*, were quite large and spectacular), and, as Darren had mentioned above, with fissipeds in NA. Some xenarthans might also have been carnivorous, or at least omnivorous. There also were ziphodont crocs in SA. In isolated SA, avian and mammalian predators seemed to have occupied different niches, with the terror birds being running predators, the sparassodonts being ambush predators. In NA, there must have been direct competition with some of the fissipeds, as must have been in SA after the opening of the Panama land-bridge.

Dominance is a matter of definition. Predators might kill each other in a fight over a carcass on an individual level, but they might still occupy niches that are different enough for cohabituation on a broader, ecological level. Are lions dominating hyaenas, or the other way around? What we know for sure is that terror birds survived the Pliocene bolide impact in SA, and sparassodonts didn't (with the possible exception of *Thylacosmilus*), so perhaps the phorhusracid population was larger in the first place?

Good blog! Another, er, feather in your cap....

My grad advisor works on sigmodontine mice. The consensus view is that they originated in North America and only radiated in South America later. The question of whether they island hopped before the opening of the Panamanian isthmus has been a longstanding one in this group as has the further question of whether only one or a few species island-hopped down and radiated in situ or whether multiple lineages might have crossed down over time.

Note that the suborder fissipedia is defunct. I just used "fissiped" instead of "carnivore" to avoid confusion between carnivora (the clade) and carnivorous.

How vulnerable would the North American terror birds have been to egg-scavengers? I thought that the South American birds went extinct due to the influx of egg-scavenging mammals after the land bridge formed. What saved their North American cousins from scavengers?

Nathan, I am ALL ABOUT that picture. If I weren't so damn busy with other art projects, I would take you up on that. Hell, I can at least produce a rough sketch...(begins brainstorming)

Once again a great post. I have to say that it is really sad that Titanis had not this clawed wings, because it was one of my all-time favoroutes among extinct predators and one of the coolest beasts ever.
I had also (again such a coincidence) a discussion in a forum about the conservation of knowlegde about prehistoric animals in the collective memory and folklore, including the "Raven" (about which I read just some weeks ago in "the beasts that hide from man" for the first time). There is no doubt that memories about distinct animals can survive for many decades or even some centuries after the extinction of an animal, like it happened in many cases at Madagascar, but I have really problems to believe that myths can survive for many millenia. I would not completely rule it out, but I can hardly imagine that a legend will survive a time of more than 10.000 years.
There are for example many creatures in the folklore of the australian natives which can be interpreted as memories of the extinct megafauna. But how sure can we be that stories about giant lizards, giant cangaroos or giant emus are actually memories about Megalania, giant marsupials or dromornithids? Animals of extraordinairy size appear in a lot of mythological tales, and perhaps is a giant emu actually nothing more than a giant emu based on an emu, and not Dromornis.

Excellent series. If I could draw like Carl Buell, I'd have a phorusrhacid duking it out with a sabertooth.

Thanks, Zach. I'm not positive that it needs a waistcoat, spats, and crop.

By Nathan Myers (not verified) on 19 Jun 2008 #permalink

Regarding the question of "how vulnerable were terror birds to egg scavengers?", my answer would be "not very", or at least no more vulnerable than ostriches, which seem to manage just fine in a continent full of carnivorous mammals large and small, monitor lizards, baboons and many other beasts with a fondness for eggs. Surely terror birds would have been at least as capable of defending their nests as ostriches are? The notion that terror birds died out because North American mammals suddenly arrived and ate all their eggs seems to be one of those "Just So" stories that paleontologists are often rightly criticized for telling. It's possible of course, but there are plenty of counter-examples that can be deployed against it. It's self-eveident that Titanis managed to colonize North America and survive long enough to leave a fossil record, in the face of whatever competition and egg predation it faced from northern mammals. It's fascinating to speculate about why this or that extinct animal succeeded or failed in a particular environment, but the sad truth is that in most cases we'll never know!

By Dave Hughes (not verified) on 19 Jun 2008 #permalink

Sordes said:

But how sure can we be that stories about giant lizards, giant cangaroos or giant emus are actually memories

Hard to tell, of course. Do the stories give specifics of events naming individuals and known places with links to family history and relics, or are they in the 'legend' class? ('once upon a time')?
But can I suggest (as others have suggested, eg Adrienne Mayor ) that people of the past finding even skeletons of extinct beasts could have come to some sound conclusions about their living forms? Especially in hunter-gatherer societies where communal butchering and roasting of carcasses over campfires (and training youngsters how) would provide many opportunites for cross-species anatomy lessons and accompanying story-telling? And extrapolation, linking found megafaunal remains to 'like what we just ate, but bigger'?

Of course, in such telling, fact and fiction may merge...
as many a parent knows.

Will our descendants, picking over relics from our civilization, imagine we really believed in (perhaps saw) Godzilla? Or that we knew of a real Valley of Gwangi, Isla Nublar and Isla Sorna, which we then imaginatively portrayed?

By Graham King (not verified) on 19 Jun 2008 #permalink

Mike and Darren - re. kiwis swimming. Kiwi scientist Dr Hugh Robertson tells me that the birds are quite good swimmers over short distances (e.g. across rivers) but doubts they would be able to cover more than about 100m. At Saxon hut area of the Heaphy Track in the Sth Island, some great spotted kiwi territories spanned rivers that were 5-10m wide and 1-2m deep, but in general rivers usually mark territory boundaries, so Hugh doesn't think they particularly like to swim. Hugh tells me he has only seen one kiwi swimming - when it was let go after capture, it leapt from the riverbank into a pool and swam (with bill pointing up like a snorkel) about 5m to shore and ran off.

Hugh also says he's never seen a moa swimming, so can't help there !

On the other hand there is plenty of evidence for good swimming ability in the weka (Gallirallus australis, another flightless NZ bird. Following transfers to other small islands, weka have often swum 1km or so to get back to their original location. Wekas are rails, though, so I guess good swimming ability could be expected.

By Ian Govey (not verified) on 19 Jun 2008 #permalink

Awesome post! This is rapidly turning into my favorite science site!

By Greg Stephens (not verified) on 19 Jun 2008 #permalink

About legendary monsters.

I find it intriguing that all human societies have legends about the same classes of monsters. There are roughly five: giant snake/reptile, animal-man, huge land beast, big cat, huge water beast. They abound even if real model is non-existent - North Europe had no dsangerous reptiles, but rich folklore of dragons and lindworms.

My pet theory is that human has evolutionary fear of major predators - snakes, fellow hominids, big cats, elephants and other pachyderms and crocodiles. It still manifests in interest of any story that such a beast is supposedly sighted in the vicinity.

This sort of idea has been suggested before, and in particular has been discussed a lot by Jon Downes (of the CFZ, a research organisation that goes on cryptozoological expeditions). In addition to big cats, giant reptiles and big hulking hominids, Jon suggests that the prevalance of 'big birds' in cultures worldwide might also reflect our primordial fears of being predated upon.

Of course, some people have taken this even further and point to child psychology (e.g., fear of monsters under the bed). I recall one study where the author purported to showed (via interview data) that young girls were more scared of 'creatures under the bed' than were boys. Because australopithecine females were smaller than males (or so it was thought at the time: this is no longer so clear), maybe only females took refuge in trees in night - and this, the author proposed, explained the psychology of little girls. I am not endorsing this, just reporting it :)

Hi, interesting.

I also find it fascinating that humans like some scary stories, but only certain types. Dragon eating virgins is an acceptable bedtime story. Knight killing women is not.

Maybe it has to do with dual function of megafauna - as both danger and food.

I recall one study where the author purported to showed (via interview data) that young girls were more scared of 'creatures under the bed' than were boys.

Via interviews? This asks for biases like boys being more afraid of admitting to being afraid.

By David Marjanović (not verified) on 20 Jun 2008 #permalink

You can often read that dragons are existent in every culture, but if you take a closer look at this, you can see that this is actually not the fact. Not only have not all culture dragons in their legends, but the "dragon" is often also more an interpretation. Can we call a giant lizard from the australian folkore really a dragon although it was most probably based on the monitors? Other ones which are described as some kind of man-eating fish-lizards are most probably based on saltwater crocodiles. Other animals are also hardly a real dragon. Can we really count a winged snake with feathers like Quetzalcoatl as a dragon? There are also many similar cases. The old european cultures knew not much or nearly nothing about dragons, you will for example find nearly no motivs of dragons in early celtic or germanic artwork or myths. The "big time" of dragons was much later, and there was also a remarkable evolution of the dragon from a very small snake-like animal to a giant four-legged and winged beast with horns and the ability to breath fire.
There are also some other kinds of creatures which exist in the folklore and mythology of completely different cultures, and I suppose they really emereged independently. For example giant, especially man-eating ogres, are found from north-america right to the native peoples of Australia or New Zealand. Dwarfs or better said, small humanoids are also very common worldwide folklore, and there are in fact also a lot of creatures which bear very vampire-like traits.

David, I recall this study too. It was actually not that the boys showed no fear at all, but it turned out that young girls have much more often fear from things under their beds than young boys, and in contrast boys fear comparably often things which are in their wardrobes, i.e. things which are not under them, but somewhere around them. I can´t help, but I think this sounds really not that unprobable. I had also sometimes fear that there could be something in my wardrobe when I was still young (okay, I have to add that I read a horror-story about a monster in a wardrobe written by Steven King, which I found in a book from my mother, but that was not the only reason).

Another common motif in legends worldwide, which may also relate to legends of giant beasties, is that there is often some idea that things were 'different' in the past (e.g. people didn't die, women ruled over men, a day could pass in an hour, etc.) before some god/ancestral hero/whoever did something to bring about the current state of affairs, which are explained and/or justified by the myth. Giant beasties could be one factor in ancient 'otherness'.

I'd also agree with Sordes that one should be careful of making inferences from the 'shared' presence of certain mythological motifs when such correlations might have been artificially imposed later by translaters trying to find a usable term. For instance, the claim that European and East Asian cultures both have legends of 'dragons' overlooks the fact that apart from being generally reptilian the two cultures' concepts of 'dragons' have almost nothing in common.

> Dwarfs or better said, small humanoids are also very common > worldwide folklore,

If we knew the Chatham Islanders only from Maori folklore, we would consider them a mythological race of dwarfs. In reality, they were fairly standard polynesians. Their culture was just too pacifist to be respectable by Maori standards.

Darren, a cryptic post on 'monsters under the bed & in the wardrobe' coming soon?

Excellent posts! Swimming? Bald eagles breast stroke, penguins flap their forelimbs to propel, I guess it's possible Titanis could have swum for short lengths or floated on currents on vegetation rafts.

I'm of the opinion that a Panama bridge had existed much earlier than thought, but "washed out" over and over, until the Americas finally jammed tightly together; the current Caribbean isles being actually the bulged-out remnants of various former land bridges which have been pushed eastwards by the former west-east Pacific current. I wonder how that matches up with various migrations.

which have been pushed eastwards by the former west-east Pacific current.

No, land doesn't get washed around by sea currents. (Cuba doesn't consist of sand, it's a rock.) No, the current went east to west.

On the other hand, it may well be that sea-level changes exposed and flooded the Panama landbridge several times before it became definitely exposed. It may also be that the real event is not the completion of the landbridge, but the possibility to bypass the rainforest during glacials.

By David Marjanović (not verified) on 22 Jun 2008 #permalink

I was under the impression from a TV show a few years ago about the Caribbean and South America that the Panama land-bridge rose further west, and was pushed into position by continental drift, which might be what DDeden is thinking of. I'm not aware of any suggestion that the Caribbean islands are anything to do with this process however.

By Dave Godfrey (not verified) on 22 Jun 2008 #permalink


explains what I meant, the Aleutians are bulging southwards, the antarctic circumpolar current is bulging the antarctic-Chile land bridge eastwards, the caribbean isles were bulged eastwards by the west-to-east pacific current at some past period; all of this was due to the solunar tidal differential AFAICT which moves land masses.

DM: any map of a east-west current available on-line?
DG: Yes, but the caribbean isles were still earlier, and had been located at the same relative position as today's Central America, before bulging eastwardly at some point in time. Actually the caribbean isles are complex, as if they had been a bridge which broke and then reformed linking the Americas, before finally breaking off again. The time before reforming may have been when there was an east-to-west current existing (per DM). This may sound odd, but it conforms to Wegeners tidal theory.

"Excellent series. If I could draw like Carl Buell, I'd have a phorusrhacid duking it out with a sabertooth."

Well, it's on a sheet of French postal stamps now.

By Christophe Thill (not verified) on 23 Jun 2008 #permalink

Congratulations on a brilliant website, interesting and informed posts & discussion.

A little observation: the 2005 Indian Ocean Tsunami shows that anything on the shore can end up out at sea. Humans survived on tree rafts for a week or more. See http://news.bbc.co.uk/2/hi/asia-pacific/4147937.stm

Tsunamis aid islands hopping by littoral (non flying / non swimming?) species. A semi continuous chain of land is not needed, but the ocean currents still need to be fortuitous.

By Dave Buckley (not verified) on 01 Jul 2008 #permalink

Recently, it has been reported that evidence exists that paleoindians came to the New World about 50,000 years ago and that they quickly spread to South America. If Terra Birds survived until the Late Pleistocene, then how is it possible that humans did not know the Terra Bird?

I accepted the view of Titanis as having clawed forelimbs rather than vestigial wings because that's the way it's depicted in the June, 1997 edition of "Discover" magazine. However, since that issue also makes the absurd claim that the giant ground sloth, Megatherium, was a predator, this is a good cautionary story about not believing everything you read!

By Raymond Minton (not verified) on 23 Aug 2009 #permalink

Wow that one realy big birdie thats for sure and no doubt a predator just imagine having one for a pet

This part

Wow that one realy big birdie thats for sure and no doubt a predator

contradicts this part:

just imagine having one for a pet

Don't you agree?

By David MarjanoviÄ (not verified) on 09 Sep 2010 #permalink

I have a question:
How many phorusrhacids are actually known from complete skeletons and what are their names?

Island hopping could include involuntary swimming, such as being blown into the sea in a hurricane and floating to the next island, possibly perched on a floating branch.

I agree that island hopping could be a plausible concept for the spread of the species. Speculating on this bird reminds me, in a way, of a friendship of mine, that I have (or had) with a friend. Of mine. Although the existence of this friendship in the past has been proven, I am now unsure of it's status; it is in a way a "cryptid friend" situation. Do you think I should make an effort to resurrect the relationship from the remaining DNA (Dormant, Nihilistic Affection), or should I continue to search for it "in the wild"? Please help me.