Whoah, um, nuh uh. Ravens in National Parks have been observed to have learned how to unzip backpacks to get at the power bars inside. They’ve even been observed teaching this skill to other ravens.
There’s a lot of recent work on bird intelligence; you need to update, Blake.
If some Synapsids evolved into a modest civilization and then were wiped out in the Permian extinction we wouldn’t know about it because nothing would be left unless they got to the plastic stage or made some incredibly durable architecture and we were lucky enough to find it. Ditto for dinosaurs or anything else 100+ mya.
Don’t agree - the very earliest tools made by humans at least are the most durable: worked stone tools. Those would last pretty well forever.
It is hard to imagine any human level intelligence not making stone tools at some point. Any Tyrannosaurus skeleton with a knapped flint projectile-point buried with it would be pretty conspicuous IMHO.
Piffle - a couple million years is not “forever”. A couple turns on the old tectonic rollercoaster and they’ll be unrecogniseable.
If they last as long as the Burgess Shale, I’ll be content. 
The only drawback is that they always have to wipe with their nose (trunk).
Birds are weird. On one hand they can have some very sophisticated behaviors, on the other hand those behaviors seem very inflexible compared to equivalent mammals. As an obvious example, consider the cuckoo. The host parent birds stuff the gigantic maw of the baby cuckoo with food, but can’t seem to recognize that the “baby” is already 5 times their size. (http://uh.edu/engines/reedwarblerfeedingcuckoo.jpg). Or you put a bird’s head under its wing, and it instantly goes to sleep. Just take a deep look into the eyes of a chicken, and you’ll find an alien creature staring back.
There has been a considerable secular increase in brain size in Mammals during the Cenozoic. Early mammals like Uintatheres had shockingly small brains compared to modern mammals. Like cows and sheep. We’re not talking primates or raccoons, we’re talking being outclassed 10 to 1 by a sheep.
Cetaceans and primates and proboscidians are clearly much more intelligent–however you want to measure it–than other mammals, and mammals are clearly much brainier than other animals. And there are lots of really brainy Carnivora–raccoons, mongooses, otters, bears, foxes, wolves, coyotes, seals, and so on.
Not that any of these creatures would have started making stone tools and mastering fire if hominids had been wiped out 6 million years ago. But perhaps the general trend in increasing brain size would have continued, which would have increased the likelihood of another species or group of species a couple of standard deviations from the mean.
Here’s an idea: If things had gone a little different way back when and the standard anatomy for land-dwelling vertebrates included six limbs instead of four, then vertebrates of several different families might have, by chance, evolved to walk on four limbs, leaving the front two free for manipulation (think a centaur) – thus, the hand-stimulus to mental evolution arises in many different and varied niches, without depending on the much greater and unlikelier complication of developing fully bipedal locomotion – thus, a world with many different kinds of sentient or near-sentient vertebrate species.
Lemur866, you’re biased – you’re a lemur.
My standard pedantic complaint:
“Sentient” means to be possessed of senses. All animals are sentient.
As to the OP, I think there are lots of candidates. Raccoons, octopi, cats, bears, birds, meerkats, otters, rats. Given enough time perhaps a reptile could make it.
Yes; I’ve speculated about that for years. Especially when I hear someone talk about the unlikelihood of technological races on other worlds due to all the fortuitous accidents that led to us. Well, the vertebrate limit of four legs is a un-fortunate accident; I wonder just how many other ways we’ve been handicapped by history compared to hypothetical alien species.
I rather suspect that no matter what form sentience takes, there would only be room on a planet for one species to evolve human-style sentience at a time; because the first to do so would very quickly spread and eliminate or marginalize all the others.
:mad: Bullshit! Gene Roddenberry trumps Noah Webster!
That’s how it went on earth within the genus Homo. But the . . . I guess you could call it the “hexworld” . . . scenario I’m proposing would allow for a wider variety of SENTIENT :mad: species to evolve more or less simultaneously on several different continents and, perhaps, in several different ecological niches not in direct competition.
Something like the old Flash Gordon comix.
My concern is that developing sentience (
) and sticking to one’s own ecological niche or geographic location may not be compatible.
How can there be any basis for debate about the topic of the OP?
Perhaps a symbiosis would have succeeded. Otters riding on the backs of ostriches, for instance. Ottstrichs.
If they evolved this symbiosis in the eastern Alps, they could call their territory the Ottsterreich.
<Devil> Tom, you’re come for. </Devil>
Lemur, the mistake you make in:re birds, is that you talk about them as if they’re a monolithic, well, species. They’re not. Pointing out unintelligent behavior in this bird species or that has no validity in this discussion. It’s like suggesting the fact that there are less-intelligent primates makes Primate intelligence unlikely.
I’d never even speculate that a European Cuckoo could evolve sentience. But a Raven, or other Corvid? Or an African Gray parrot, or other Psittacine? I’m less sure of the unlikelihood.
Nothing in the Burgess is the same shape it was in life- most is just just thin carbon films on shale. How recogniseable do you think stone tools would be under the same preservation conditions? I doubt anyone could tell a billion yo midden from a breccia
