Why are there big cats but no big dogs?

[datalink7]

Why are there no 10ft tall spiders?

Because this one is big enough:

 

[Phokus]

WTF, that's like a small horse.

 

[PingSpike]

It's a common misconception that humans out-competed the other hominids causing them to go extinct. Homosapiens were actually just the only species that survived the Great Spider Wars.

 

[KMFJD]

Because this one is big enough:

Saw one of those at a camp ground.....damn big spiders

 

[zinfamous]

Because this one is big enough:

that may not be my house, but I will not be getting much sleep tonight...simply knowing that that vile creature is out there...somewhere

D:

 

[skyking]

Those look like cane spiders.


We were staying one night at a B+B in Hilo a few years back. We got back from dinner, and I spotted one of These bad boys in the foyer between our rooms. I managed to turn my wife away, and also my aunt and uncle. "hey look, it's Halley's comet"
Everybody went to bed, and I snuck out and herded that monster right back outside. I told no one about it, I figured they would not sleep

 

[epidemis]

Perhaps they developed into bears.

 

[spacejamz]

 

[BudAshes]

Perhaps they developed into bears.

This is what I was kind of thinking. My st bernard looks half bear.

 

[datalink7]

This is what I was kind of thinking. My st bernard looks half bear.

My dog kind of looked like a baby bear when he was a puppy:

 

[BudAshes]

My dog kind of looked like a baby bear when he was a puppy:

what kind of dog is it?

 

[datalink7]

what kind of dog is it?

German Shepherd.

Here he is grown up:

 

[bfdd]

beautiful dog ^

btw I agree with Woosta, Orcas are badass

 

[Gooberlx2]

German Shepherd.

Here he is grown up:

Gorgeous! (or handsome, rather)

 

[datalink7]

Thanks for the compliments

 

[bfdd]

btw that picture would be awesome with the caption "I do cocaine... seriously"

 

[rockyct]

German Shepherd.

Here he is grown up:

I usually don't like the look of German Shepherds but that's one good looking dog.

 

[BudAshes]

German Shepherd.

Here he is grown up:

His coloring is fantastic.

 

[datalink7]

btw that picture would be awesome with the caption "I do cocaine... seriously"

And how would you caption this one?

 

[Gigantopithecus]

and how would you caption this one?

omg that's the biggest spider i've ever seen! Ahhhhhhh kill it with fire!!!

 

[MovingTarget]

There is also speculation that dinosaurs simply had a more efficient metabolism, but whatever the case modern birds do not get that large and mammals haven't been around nearly as long leaving the exact reasons up for debate.

Maybe it is a good thing these aren't still around:
http://en.wikipedia.org/wiki/Terror_bird

 

[So]

So that's why the blue whale is the largest animal ever, we have less O2 today?

Techs is both wrong and right. Dinosaurs did not grow large because of higher O2 concentrations. Insects, however, breathe differently than vertebrates, and they did grow larger in the past because of higher O2 concentrations (1m wingspan dragonflies)

 

[futuristicmonkey]

That's not Awesome; this is an Awesome: