Gastornis Not Such A Terror After All

[suspsy]

http://blog.everythingdinosaur.co.uk/blog/_archives/2012/11/24/diatryma-scientist-postulate-that-this-terror-bird-may-not-have-been-so-terrible.html

This makes a lot of sense to me. It would definitely explain how Gastornis could survive when it moved so slowly.

[Jetoar]

I think that Gastornis was a omnivorous bird. I think that ate plant but he could be a ambush predator  and he killed his prey with stomps and with his beak also.

[Horridus]

With the extinction of the Dinosauria at the end of the Cretaceous

...Wait, what!?!

There's only one thing that doesn't seem to square with it being a herbivore - the sheer size of that head. However, comparisons with the phorusrhacids are interesting, in that the latter have the downturned bill tip and raptorial claws.

[Gryphoceratops]

I remember hearing this before somewhere.  Interesting.  Looking at modern parrots- they have huge powerful curved beaks for ripping apart tough nuts and fruits.  I've even heard stories of wild cockatoos carving out chunks of concrete between the bricks on buildings.  I guess its possible for Gastornis not to be such a killer?

[Takama]

I always thought Gastornis used its big beak to mush up fruits.

Though i can now see it  crack a Coeco Nut.

andi imagine that its still dangerous. If an ostrich can kick a lion, then would it be possible for Gastornis to kick?

[Gryphoceratops]

I always thought Gastornis used its big beak to mush up fruits.

Though i can now see it  crack a Coeco Nut.

andi imagine that its still dangerous. If an ostrich can kick a lion, then would it be possible for Gastornis to kick?

Or bite!

[Balaur]

This is very intresting! I've always thought they were carnivores! Wow! I was about to draw a Gastornis eating a propaleotherium! Good thing I looked at this! I don't know what to say! This is amazing! And this is why I love science! Theories change, and sometimes they are cooler than the original idea!

If this is true, Gastornis would be like Dromornis, the flightless bird similar to Gastornis that was herbivorous. Again, intresting... And awesome! 

I love Eocene dinosaurs! 

[Iguanocolossus]

I've heard this theory so many times for both Gastornis and Dromornis, and it's never convinced me. Two big problems:

1. If you think you need claws to be a predator, then you need to meet Tyrannosaurus

2. Terrestrial birds with big heads-Phorusrhachids=predator
Terrestrial birds with small heads-Ratites=herbivore
That one Dromornithine that turned out to be herbivorous, Genyornis? Small head compared to the rest of the family
See a trend here?

[Balaur]

I've heard this theory so many times for both Gastornis and Dromornis, and it's never convinced me. Two big problems:

1. If you think you need claws to be a predator, then you need to meet Tyrannosaurus

2. Terrestrial birds with big heads-Phorusrhachids=predator
Terrestrial birds with small heads-Ratites=herbivore
That one Dromornithine that turned out to be herbivorous, Genyornis? Small head compared to the rest of the family
See a trend here?

This is talking about birds specifically. Their not saying they have no claws, their saying that ALL predatory birds have long curved talons. Gastornis doesn't, which hints at it being a herbivore.

Also, a big beak doesn't mean it's a carnivore. In fact, that beak looks like is was useful for eating fruit and plant matter than to tear flesh and eat at its victims. All predator birds have long curved beaks, for smashing into prey. Gastornis doesn't. 

To me, this is and it's half ton weight is enough to show that Gastornis was a herbivore.

[Iguanocolossus]

their saying that ALL predatory birds have long curved talons

Apples to oranges. All predatory birds today can fly. Even those that hunt near the ground still fly.  And guess what? The larger a raptor's talons are, the smaller the beak is.The golden eagle hunts with its talons, which is why the legs are so strong and powerful; meanwhile, the beak is reduced and only used to consume prey.

Also, a big beak doesn't mean it's a carnivore.

It does. I refer you to my living birds example.

In fact, that beak looks like is was useful for eating fruit and plant

You don't need that big a bird to eat plants. If you try to use the toucan-it's a bad idea. A toucan's beak isn't built mainly for power, but for reaching. When you're 6 feet tall, you don't need a big beak.

Most nut-eating birds are small. If you look at ratites, they don't eat nuts. They eat smaller seeds and grass, and digest them with a gizzard. All the big terrestrial birds we know of have small heads and feed on small parts of plants.

To me, this is and it's half ton weight is enough to show that Gastornis was a herbivore.

Predators don't have to be the size of their prey, you know. Look at foxes, or even better, Spinosaurus. Spinosaurus ate 10-foot fish, and yet it was 60 feet long and might have been up to 20 tons. The animals bigger than it were probably usually not prey.

[Gryphoceratops]

"The larger a raptor's talons are, the smaller the beak is."

I don't really think this holds up.  Philippine Eagles, Bald Eagles and Stellers Sea Eagles have large powerful beaks and huge talons.

"It does. I refer you to my living birds example."

http://www.freeinfosociety.com/media/images/3983.jpg

herbivore.   Large powerful beak specially adapted for cracking nuts and tough fruits.  Who's to say Gastornis wasn't frugivorous or a nut cracker? 

Keep in mind I'm not necessarily in favor of either idea over the other.  But I think this new theory could make sense.  Do we know anything about the environment Gastornis was living in?  I wonder if there was some sort of gigantic hard-shelled nut or a tough fruit that it would have been adapted for cracking with that massive beak.  Gastornis skulls don't seem to have a definite hook on the end of the beak either like those on predatory birds. 

Maybe it ate both meet and plant material?  Toucans and Hornbills are omnivores and also have large beaks. 

I'm trying to keep an open mind here haha.

[wings]

...2. Terrestrial birds with big heads-Phorusrhachids=predator
Terrestrial birds with small heads-Ratites=herbivore
That one Dromornithine that turned out to be herbivorous, Genyornis? Small head compared to the rest of the family
See a trend here?

This is a short version to your question (see http://dml.cmnh.org/1998Mar/msg00383.html)  and as for a more detail explanation here is one from the book "Magnificent Mihirungs" (see http://books.google.com.au/books?id=-t6cQHdVEggC&pg=PA259&lpg=PA259&dq=watson+1976+diatryma&source=bl&ots=v5D_RsBb3N&sig=FAu90MdPukpUCVDG2FvguP2chuc&hl=en&sa=X&ei=st26UMvVM8-cmQWytoGoCQ&sqi=2&ved=0CDEQ6AEwAQ#v=onepage&q=watson%201976%20diatryma&f=false, the section titled "Diatrymatids and Phorusrhacids") and also if you look at this page (see http://books.google.com.au/books?id=8QRKV7eSqmIC&pg=PA233&lpg=PA233&dq=watson+1976+diatryma&source=bl&ots=fpV5dLcEAe&sig=94hfNE_5LHvl6FczxZyJ4t3pvb0&hl=en&sa=X&ei=st26UMvVM8-cmQWytoGoCQ&sqi=2&ved=0CC8Q6AEwAA#v=onepage&q=watson%201976%20diatryma&f=false) you would see that Diatryma (Gastornis) are proportionally more of a graviportal animal like the Dinornis and Aepyornis. Its cannon (foot) bones are rather short and robust compare to other phorusrhacids which implies it's less of a runner than them (of course being fast doesn't imply that you are a predator but being slow is certainly a disadvantage). This is not to say that Gastornis is definitely a herbivore but just to point out that most of the elements that you've raised is not totally irrefutable and the possibility is still open, unless there is more persuasive evidence it is hard to favor your strictly carnivorous theory right now.

[Yutyrannus]

"Apples to oranges. All predatory birds today can fly. Even those that hunt near the ground still fly.  And guess what? The larger a raptor's talons are, the smaller the beak is.The golden eagle hunts with its talons, which is why the legs are so strong and powerful; meanwhile, the beak is reduced and only used to consume prey."
That is NOT true. Steller's Sea Eagles and Phillipine Eagles have enormous beaks AND talons!

"

Also, a big beak doesn't mean it's a carnivore.

It does. I refer you to my living birds example."
Uh, no it doesn't. Parrots and macaws have bigger beaks than almost ANY predatory birds, and they are ENTIRELY HERBIVEROUS!
Also, IF Gastornis actually did eat flesh, it would not have done so well, as 1) Its bill wasn't particularly sharp, and 2) It lacked a hook on its bill which are almost essential to tearing flesh.
"In fact, that beak looks like is was useful for eating fruit and plants."
Very true!
"Most nut-eating birds are small. If you look at ratites, they don't eat nuts. They eat smaller seeds and grass, and digest them with a gizzard. All the big terrestrial birds we know of have small heads and feed on small parts of plants. "
HELLO! Aren't you forgetting something?! HYACINTH MACAW!!!!!!!!!!!!!!!!!!!!!

"Predators don't have to be the size of their prey, you know. Look at foxes, or even better, Spinosaurus. Spinosaurus ate 10-foot fish, and yet it was 60 feet long and might have been up to 20 tons. The animals bigger than it were probably usually not prey."
Spinosaurus almost certainly ate more than that! Fish were just a large part of its diet, not all of it!

[Seijun]

Claws and beak size aside, I think the lack of a hook on the beak would be the strongest evidence against Diatryma being a predator. How would it tear apart flesh without a hooked beak?

Regarding herbivore birds with hooked beaks, parrots are the best example I think, but they are also very unique in that their top mandible is hinged and can move independently of the bottom mandible. I do wonder why there are not more species of parrots that are predatory. They seem like they would make great predators. The kea is the only parrot I know of that actually kills and eats other birds (the kea is an omnivore though, not a strict carnivore).

Other species, like kelenken, definitely have a hooked beak, and I think might have been predators. Maybe the predatory "terror birds" preyed on herbivorous "terror birds"?

As for why a plant eating animal would need to be that big, why does anything need to be big? Why do horses need to be big? Or elephants? Sorry, it just seems like a weird question. Aren't there lots of theories floating around already to help explain why animals evolve to be bigger?

[darylj]

This is very I interesting and I think the herbivorous theory holds a lot of credit.
large size, non hooked beak,
does anyone know the perephiral vision capabilities of this bird?

I really dont give much to the ambush predator idea.
I really hate when they find an animal and there like ''well it's like a predator, but... Blah blah blah, so it must have been an ambush predator.

Im in favour of the herbivorous idea.

Also, I wouldnt be so sure that spinosaurus certainly ate more than just fish... But thats another topic

[tyrantqueen]

This is very I interesting and I think the herbivorous theory holds a lot of credit.
large size, non hooked beak,
does anyone know the perephiral vision capabilities of this bird?

I really dont give much to the ambush predator idea.
I really hate when they find an animal and there like ''well it's like a predator, but... Blah blah blah, so it must have been an ambush predator.

Im in favour of the herbivorous idea.

Also, I wouldnt be so sure that spinosaurus certainly ate more than just fish... But thats another topic

It's assumed that Spinosaurus might have filled out the rest of its diet with carrion, much like most other theropods probably did.

[darylj]

ah, sorry, of course. I was more suggesting that it didn't hunt terrestrial animals.
i completely agree that it would not turn down a free meal if it found one

[Iguanocolossus]

Actually, I'm growing more fond of the omnivorous theory that a strict diet of either meat or plants. Look at bears. Even Arctodus was an omnivore. I think bears are really the best analogy-capable eating anything that it comes across. Bears certainly eat a great deal of plants, but they're also very good predators.

As for flesh-tearing, with a head that big, you don't need to dismember prey. You can crush them with one bite and then swallow.

does anyone know the perephiral vision capabilities of this bird?

Excellent idea. They should also do one for Phorusrhacids as well.

HELLO! Aren't you forgetting something?! HYACINTH MACAW!!!!!!!!!!!!!!!!!!!!!

What part of "terrestrial" aren't you getting here?

you would see that Diatryma (Gastornis) are proportionally more of a graviportal animal

You don't need to run when hunting small, slow animals in a dense forest

Do we know anything about the environment Gastornis was living in?  I wonder if there was some sort of gigantic hard-shelled nut or a tough fruit that it would have been adapted for cracking with that massive beak.

A very good question. I think we need to do that before we jump to conclusions like the writers of the article

[Horridus]

It's assumed that Spinosaurus might have filled out the rest of its diet with carrion, much like most other theropods probably did.

Indeed, there's fossil evidence of spinosaurs having eaten iguanodonts and pterosaurs, as well as fish.

[Paleo & Fish Collector]

Noooo!
Coolest bird ever a herbivore? Man I liked it better when it shredded little forest animals!
http://www.tapirback.com/tapirgal/gifts/friends/birds/bird-long-tailed-plastic-animals-f619.htm
(Confuciusornis)
Come on people! In case you guys didn't know,this plastic Nayab bird is actually a primitive bird!
And from 3 years of reading here on the forum,I have not seen a single thing about this bird!
    *orthocone*