Is it utterly impossible...[civilization existed on Earth 100 million years ago?]

In My Humble Opinion
61

You won’t have agriculture without stone tools. You can’t clear fields with wooden tools, or harvest grain without sickles. Even a pure vegetarian intelligence would need hard tools to develop agriculture. And the big-brained dinosaurs were all meat-eaters.

Plus good luck developing a serious agricultural society off of gymnosperms and podocarps. Grasses, squashes, legumes and the like didn’t evolve until well after 100Ma.

I’m not saying you couldn’t have an intelligent species that develops like you say, somewhere. I’m saying you can’t have it on Earth, 100 Million years ago.

62

Prior to the ending of the last ice age there was an advanced civilization living on the coast of what is currently subducted Antarctica. When they saw their world coming to an end via rising sea levels the few survivors spread their knowledge to the rest of the world as best they could.

This explains the South American mythology of a pale-skinned, bearded species of God-men that provided knowledge of the world to the natives. The Spaniards arriving to America were unfortunately considered the return of these divine beings.

It also explains the astrological alignment of the Giza pyramids and the Sphinx. In 10,500 BC, the pyramids correlate exactly to how Orion’s Belt appeared in the sky. Today, the alignment is off. Similarly, in 10,500 BC the Sphinx was facing the constellation Leo as the sun rose from the West. The Sphinx, of course, was originally a Lion with the head later being re-carved into the form of a human. And there is the water erosion on the Sphinx plateau, that could only have occurred when Egypt had running water, which is at least 8,000 years ago…

This is all part of a theory by Graham Hancock who speculates that there was an antediluvian civilization that was wiped out by the end of the ice age and whose few survivors gave the earliest spark of civilization to the primitive people elsewhere. The clear astrological dating in the Egyptian monuments to the period in which the ice age was ending (roughly 10,500 BC) is the coded message we are only beginning to decipher.

63

How do you know it did not remove all traces of at least some species of dinosaurs? How about some kind of intelligent plant-like or less-than-mobile colony-based lifeforms that did not have hard skeletons? If you get away from the conventional view of intelligent life (bipedals with technology, weapons and large cities), it is not hard to imagine an array of “intelligent” lifeforms with physical and chemical makeups so different they would not enter the fossil record at all.

64

Recent research allows rice as early as 120 million years ago. Besides, I think a civilization 50 million years ago would be just as interesting, and would still allow time for geological or cosmic disasters.

Your point about the tools needed to harvest crops is well taken, but again, it’s easy to think of scenarios where we wouldn’t have found them yet.

65

Approximately what percentage of the earth’s surface has been excavated to the point that artifacts only 100 feet below the surface would have been found?

Google yielded an articlethat says urban areas cover 3% of the land surface of the earth, and probably very little of that is subways, or buildings whose foundation requires excavation more than 100 feet deep. I can’t think of any reason to dig that deeply in rural areas other than mines and wells, or maybe an occasional highway cut, which I would doubt comprise more than a small fraction of 1% of the earth’s surface.

Land surface is only about 30% of the earth’s surface, so it seems that 99% of whatever is 100 feet below the surface of the earth or the bottom of the ocean has not been seen.

Knowing that lava flows may be over a mile thick, I think that makes it ridiculously easy to imagine scenarios where stone (or even iron) tools and artifacts from tens of millions of years ago would remain undiscovered.

66

Well this has just been found from 100 million years ago. Don’t know how civilized he was.

67

If you dig down 100 feet anywhere in the world you’re going to find either alluvium (dirt, gravel, etc) dating back to somewhere in the hundreds to hundreds of thousands of years range or you’re going to find bedrock that’s essentially similar to the stuff that crops out somewhere else nearby. If there’s any lost Mesozoic cultures, they’re not hiding right under someone’s backyard.

More generally, though, what’s your point? Everyone’s agreeing that if there were a tiny little pocket of civilization somewhere, the odds are fairly overwhelmingly against us knowing about it. The question is really whether it’s really possible to have a small local civilization without also having a more widely distributed tool-using culture, which probably would be detectable in the rock record. The point MrDibble is making is that it is not at all likely and so the absence of evidence for a tool using species prior to hominids pretty overwhelmingly suggests no tiny civilization either. I think barring sci-fi concepts or maybe the somewhat elaborate and not very likely terrane scenario I laid out earlier, he’s probably right.

68

I don’t. But it certainly wouldn’t remove all evidence of an entire lineage of dinosaurs.

On Earth? Intelligent trees or…what, siphonophores?.. on Earth? You’re in Sci-Fi territory now, I’m afraid. And very soft, practically oozing, Sci-Fi, at that (pace Lovecraft).

One paper isn’t enough to overturn the conventional 70Ma age for grasses, for me. Producing plant evolution timelines from pure genetic extrapolation, as that study is, is always tricky because of their pervasive totipotency and polyploidy. I’d prefer hard evidence, and the pollen isn’t there to back them up - and that isn’t an unstudied period for palynology.

Sure, but that wasn’t the OP’s question. And I’d still say “highly (like, astronomically) improbable” given all the other factors to be overcome.

I can’t think of these scenarios - look, I can understand us not blindingly stumbling across them, but we’ve been actively looking in just that sort of terrane, for decades now. Cretaceous basin deposits are frequent targets for oil and gas exploration. That shit gets drilled and scanned like nobody’s business. It’s not a particularly unstudied timeperiod.

69

Please give me your best guess for how much of the bottom of the ocean is 100Ma old…

70

There’s a book by Stephen Baxter, Evolution a Novel. It’s a fictional story of life on earth, each chapter a different time period, and extending into the future beyond human civilization. One of the chapters is about a species of intelligent dinosaur that evolves just before a period of major climatic change. They die out before they can advance beyond nomads with sharpened wooden spears and leave no evidence of their existance. It’s a good book.

71

I’ve bolded the bits that make this not pertinent to the idea of a real civilization at 100Ma. H.P. Lovecraft wrote a fictional story about Precambrian intelligences on Earth before we have multicellular life. That doesn’t make the Elder Thing civilization a possibility.

72

Oh dear me yes, making a fun book recommendation in a Thread, what was i thinking?

73

I don’t know, what were you?

74

Ok whoops, I think the quote is:
"It isn’t easy to become a fossil… Only about one bone in a billion, it is thought, becomes fossilized. If that is so, it means that the complete fossil legacy of all the Americans alive today - that’s 270 million people with 206 bones each - will only be about 50 bones, one-quarter of a complete skeleton. That’s not to say, of course, that any of these bones will ever actually be found. Bearing in mind that they can be buried anywhere within an area of slighly over 9.3 million square kilometres, little of which will ever be turned over, much less examined, it would be something of a miracle if they ever were”

So only Americans, and only living ones at that.

75

That’s a much more reasonable analogy.

Let’s not forget that despite some claims to the contrary, there are many more dead humansthan living ones.

And of course, this overlooks the one thing different in some human cultures - deliberate burial. Not that that would necessarily be the case for intelligent dinosaurs, of course. They might just cremate, or air-bury.

But deliberate burial would greatly increase the chances of fossilization since mechanical breakdown of bones pre-burial is a major cause for the lack of fossilization.

76

Speaking only mathematically and statistically, isn’t there a problem in assigning an independent probability to each bone? In practice, fossilization seems to work on clusters of bones. If one of an individual’s finger-bones is fossilized, then the other finger-bones of the same hand are much more likely to be fossilized also.

Thus, even if the overall probability of an individual bone being fossilized is very small, wouldn’t clusters and congregations of bones – entire hands, for instance – be more likely to be preserved than it would seem by simply raising the probability to the power of the number of bones in question?

When Caveman Jack falls into a bog, how likely is it that his left kneecap, only, avoids preservation?

77

If you’re going to have dinosaurs intelligent enough to build cities, the city builders can’t just wake up one day, look at each other, and all start building together. They have to arise from a species that already practices advanced technology.

Lost cities in the jungles of Africa, Edgar Rice Burroughs style can’t happen because a city requires farms and villages and mines and quarries and trade. A city where beyond the walls is nothing but wilderness is impossible. What do the people in the city eat? How do they pass on their technology from generation to generation? So a city requires an entire civilization surrounding the city, a network of roads and infrastructure.

And the society that the city arises from has to be widespread and successful. You can’t have five guys who build a city. The city is just one node in a society, it can’t exist on its own. It’s a place where command and control, religion, and trade for the whole region get centralized.

And this city-building society doesn’t spring out of nothing either. It comes from smaller, more loosely knit societies. Population density grows and grows and pretty soon villages are bumping against each other, and warriors from one village gain the upper hand and extract tribute from the other villages. But with a rare species this doesn’t happen, by definition since the species is rare.

The point is, a city requires a civilization. A civilization requires a wide-spread densely populated society. That society requires a cosmopolitan species with an advanced toolkit. That species must arise from an earlier species that was almost as brainy. And that earlier species must arise from a lineage of pretty brainy creatures that generate new species all the time.

And so for humans, we have brainy early primates all over the world. Some of these evolved into an even brainier lineage, the monkeys, that was common all over the world. And one branch of those monkeys, the apes, was even brainier, and lived all over the Old World, apes are rare today but in the past they were very common. And one branch of those apes developed bipedalism and stone tools, millions of years ago. Those tools and fossils aren’t common, but there are enough of them that it is implausible that they could have been overlooked.

But those early bipedal hominids with stone tools weren’t building any civilizations. They had gigantic brains compared to other mammal species, but typical for apes. Australopithecines had brains the size of a chimp’s brain. But an ape’s brain is huge compared to most mammals, and mammal brains are huge compared to dinosaur brains.

It’s not like we could miss seeing that one lineage of dinosaurs that had brains large enough to build cities. We’d have to miss the lineages with brains large enough to build stone tools. And the lineage of ape-like dinosaurs that they arose out of. And the lineage of monkey-brained dinosaurs they arose out of. And the lineage of mammal-brained dinosaurs they arose out of.

But we’ve never found anything of the sort.

A brainy species with a technology on the level of Homo erectus that arose out of nowhere is impossible. It has to evolve from previous species that would already be very large brained. And where are they?