Paleogene Dinosaurs

[Jeremy]

Has anyone come across books or websites conceived around the idea of there being no extinction event 65 million years ago?
I'm looking for speculation on how non-Avian Dinosaurs would have looked in the Paleogene. I am not specifically interested in the "sentient Dinosaur" theories, but in continued specializations like herbivorous Sauropods being supplanted by the duck-billed Ornithopods.

[hongi]

Speculative Dinosaur Project. They've recently started updating after a loooong absence, and some of the links were faulty the last time I checked which was like a year ago, but I haven't seen anything like it.

[Grandmaster Jogurt]

There's also Douglas Dixon's book, The New Dinosaurs, which I've had since I was a kid. My edition is two decades old by this point, so it doesn't use as up-to-date information, but I like it.

[Johonebesus]

There's also Douglas Dixon's book, The New Dinosaurs, which I've had since I was a kid. My edition is two decades old by this point, so it doesn't use as up-to-date information, but I like it.

That's the one with the humanoid dinosaurs, right? That alone calls into question his reliability, to me at least. A much better conjectural sapient dinosaur is Nemo Ramjet's Dinosauroids.

You can also search the blogs of Zachary Miller, Will Baird, and Darren Naish. All of them have posts on speculative biology, and will likely link to more sites, though only Naish is an actual academic.

[Grandmaster Jogurt]

That's the one with the humanoid dinosaurs, right?

In the afterword, there's a "here, let's see what they'd look like, why not", but there's no humanoid dinosaurs in the book itself. There's not even sapient dinosaurs in the book itself; the most intelligent one found is a deinonychusoid that pretends to die to attract carrion-eaters.

[Cykeisme]

Would I be wrong in saying that, unless there were a rather specific set of selective pressures and conditions, sentience doesn't develop?
I mean, it's not like it's some sort of "goal" for life to evolve senteince, or anything right?.

My knowledge in the field is anything but deep, mind.

[Vultur]

Would I be wrong in saying that, unless there were a rather specific set of selective pressures and conditions, sentience doesn't develop?

No, that's probably true. We don't know much about what those conditions need to be, though.

(It may be interesting to consider that in the current era there are four independent developments of significant intelligence: primates, parrots, corvids, and toothed whales/dolphins. All of these groups have at least one species which has shown amazing abilities in tests, and at least some degree of 'self-awareness' whatever that means: at least the ability to recognize their reflection as themselves, not a rival or another individual. In contrast, we know of no Mesozoic era animal smarter than the stupider birds, like ostriches.)

[Swindle1984]

Would I be wrong in saying that, unless there were a rather specific set of selective pressures and conditions, sentience doesn't develop?

No, that's probably true. We don't know much about what those conditions need to be, though.

(It may be interesting to consider that in the current era there are four independent developments of significant intelligence: primates, parrots, corvids, and toothed whales/dolphins. All of these groups have at least one species which has shown amazing abilities in tests, and at least some degree of 'self-awareness' whatever that means: at least the ability to recognize their reflection as themselves, not a rival or another individual. In contrast, we know of no Mesozoic era animal smarter than the stupider birds, like ostriches.)

My cat recognizes himself in the mirror. I don't find that all that impressive.

[Vultur]

Cats? Really? I'd read that that was restricted to a very few species. I guess that book was wrong...

Anyway, the basic point's still true: parrots, apes, corvids, and dolphins are all significantly smarter than anything else around. All those things are smarter than *anything* in the Mesozoic era, as are most mammal carnivores or omnivores, elephants, and passerine birds.

[Junghalli]

Anyway, the basic point's still true: parrots, apes, corvids, and dolphins are all significantly smarter than anything else around. All those things are smarter than *anything* in the Mesozoic era, as are most mammal carnivores or omnivores, elephants, and passerine birds.

In fairness, how sure can we actually be of that? We can't really test Mesozoic lifeforms for intelligence in the way we can test living species. All we have in the way of estimating their intelligence is best guesses based off brain size and maybe looking at the convolutions in fossil casts of the brain if we're really lucky. I'm pretty sure parrots have physically smaller brains than some dinosaurs.

Not to mention that the fossil record is spotty. For all we know there could have been a dinosaur which reached the material culture levels of human hunter-gatherers and we don't know it because none of their tools or skeletons fossilized, or we just haven't found the fossils.

Although it is telling that as far as we can tell even Homo Erectus was an unparralleled pinnacle of sophisticated tool use in its time.

[Vultur]

That's very true; we can't know for sure. "Encephalization quotient" is the best way anyone's come up with to get an idea of the intelligence of fossil animals, and it's nowhere near perfect. But the general trend is still clear: the biggest-brained Mesozoic animals we know, the troodontids, would fall in the lower range of modern birds. Rhinos are bigger-brained than stegosaurs; tigers are bigger-brained than T. rex.

[Grandmaster Jogurt]

How would elephants compare with the other four lines of intelligent animals? I've heard them listed as some of the most intelligent animals, but those lists also tend to ignore the intelligent birds in the comparison.