# Dinosaur Extinction **URL:** \ **Category:** Factual Questions\ **Created:** [December 20, 2015, 6:38pm UTC](https://boards.straightdope.com/t/dinosaur-extinction/740940 "2015-12-20T18:38:01Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\ **Post date:** [December 21, 2015, 5:41am UTC](https://boards.straightdope.com/t/dinosaur-extinction/740940/21 "2015-12-21T05:41:56Z")
One thing I read said that ALL large creatures died, from the initial blast or loss of food sources. One article suggested anything over about 5 pounds died, another said about 20 pounds. That doesn’t leave behind a lot, but ever seen baby alligators? Or turtles? Presumably some mammals the size of a mouse also survived…buried seeds, or small animals washed over by flood waves to prevent the heat shock presumably provided the basis for a gradual rebuild of thee ecology. ---
**Author:** ![Urbanredneck](https://avatars.discourse-cdn.com/v4/letter/u/ea5d25/32.png) [@Urbanredneck](https://boards.straightdope.com/u/Urbanredneck)\ **Post date:** [December 21, 2015, 5:52am UTC](https://boards.straightdope.com/t/dinosaur-extinction/740940/22 "2015-12-21T05:52:56Z")
I’ve always wondered why that in the hundreds of millions of years dinosaurs were on the world, that a sentient or smart dinosaur didnt develop? Why havent we found a dinosaur fossil holding a clay pot? Certainly some dinosaurs had opposable thumbs, a large brain, and binocular vision. ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [December 21, 2015, 5:58am UTC](https://boards.straightdope.com/t/dinosaur-extinction/740940/23 "2015-12-21T05:58:37Z")
> [@md2000](#): > > One thing I read said that ALL large creatures died, from the initial blast or loss of food sources. One article suggested anything over about 5 pounds died, another said about 20 pounds. That doesn’t leave behind a lot, but ever seen baby alligators? Or turtles? Presumably some mammals the size of a mouse also survived…buried seeds, or small animals washed over by flood waves to prevent the heat shock presumably provided the basis for a gradual rebuild of thee ecology. Mice weight ounces, much less than a pound. That leave a LOT of space between mice and 5 lb mammals. Keep in mind that 25% of all mammal species today are bats, the largest of which weigh only a few pounds. At 65MYA, there weren’t many mammal species that would have been \> 5 lbs. Nothing like the large mammals that are so common today. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [December 21, 2015, 6:56am UTC](https://boards.straightdope.com/t/dinosaur-extinction/740940/24 "2015-12-21T06:56:57Z")
> [@White SIFL](#): > > Fight my ignorance, we have Dino DNA? Yes - it turns out that, contrary to the popular notion that fossils are things that have turned to stone, certain fossils contain some of their original biological material, encapsulated or intermingled within a mineralised matrix. Dissolve away the intruded minerals and it is possible to recover fragments of proteins, etc. ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [December 21, 2015, 7:12am UTC](https://boards.straightdope.com/t/dinosaur-extinction/740940/25 "2015-12-21T07:12:59Z")
> [@Mangetout](#): > > Yes - it turns out that, contrary to the popular notion that fossils are things that have turned to stone, certain fossils contain some of their original biological material, encapsulated or intermingled within a mineralised matrix. Dissolve away the intruded minerals and it is possible to recover fragments of proteins, etc. I’d like to see a cite for that. There have been some news reports of Dino DNA, but the ones I’ve seen have been discredited. ---
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [December 21, 2015, 10:37am UTC](https://boards.straightdope.com/t/dinosaur-extinction/740940/26 "2015-12-21T10:37:12Z")
> [@John\_Mace](#): > > **wolpup** : Not sure if you were implying this, but I don’t believe any extant bird species can be thought of as genetically closer to “traditional dinosaurs” than any other bird species. And all flightless bird species are descended from “flightful” species. My apologies, the story that I dimly remembered wasn’t about DNA but about the similarity in the blood cell structures of recently discovered fossilized dinosaur connective tissue with that of the emu … this is not to suggest that the emu or any other bird species has any closer relationship to dinosaurs than any other, it’s just an interesting discovery. Researchers have discovered what appear to be the remnants of red blood cells and connective tissue in 75 million-year-old dinosaur fossils … Chemical analysis revealed similarities between blood cells from fossils and those from living emu. > **['Blood cells' found in dino fossils](https://www.bbc.com/news/science-environment-33067582)** > > Researchers have discovered what appear to be the remnants of red blood cells and connective tissue in 75 million-year-old dinosaur fossils. _‘Surprisingly similar’ to emu blood_ Using an electron microscope, they found red blood cell-like structures in the therapod claw and the horned dinosaur toe. When they used an instrument called a mass spectrometer to look at the chemical composition, they saw a profile “surprisingly similar” to that of blood cells from an emu, a large bird, they reported in the journal _Nature Communications_. > **[Dinosaur blood cells, proteins found in crummy Alberta fossils | CBC News](https://www.cbc.ca/news/science/dinosaur-blood-cells-proteins-found-in-crummy-alberta-fossils-1.3106247)** > > Scientists have made a surprising find inside badly preserved fragments of dinosaur fossils from Alberta. ---
**Author:** ![Captain\_Amazing](https://avatars.discourse-cdn.com/v4/letter/c/6de8d8/32.png) [@Captain\_Amazing](https://boards.straightdope.com/u/Captain_Amazing)\ **Post date:** [December 21, 2015, 11:42am UTC](https://boards.straightdope.com/t/dinosaur-extinction/740940/27 "2015-12-21T11:42:34Z")
> [@Urbanredneck](#): > > I’ve always wondered why that in the hundreds of millions of years dinosaurs were on the world, that a sentient or smart dinosaur didnt develop? Why havent we found a dinosaur fossil holding a clay pot? Certainly some dinosaurs had opposable thumbs, a large brain, and binocular vision. To play devil’s advocate, if one did, we probably wouldn’t know. ---
**Author:** ![Kamino\_Neko](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kamino_neko/32/34_2.png) [@Kamino\_Neko](https://boards.straightdope.com/u/Kamino_Neko)\ **Post date:** [December 21, 2015, 12:35pm UTC](https://boards.straightdope.com/t/dinosaur-extinction/740940/28 "2015-12-21T12:35:19Z")
> [@John\_Mace](#): > > Well, the birds weren’t killed and they’re dinosaurs, but I honeys don’t know if the group we can “Aves” were differentiated enough from the non-avian dinosaurs 65MYA that they can be thought of as separate from dinosaurs in the way we sometimes think of them being that way today. They weren’t. There were a number of other theropods that were similar enough that the definition of ‘bird’ is remarkably slippery. > [@Urbanredneck](#): > > Certainly some dinosaurs had opposable thumbs, a large brain, and binocular vision. ‘Big’ is very much relative. IIRC, the largest relative brain sizes in non-avian dinosaurs were the Troodontids whose brains were…about the size of a modern bird’s. > [@John\_Mace](#): > > I’d like to see a cite for that. There have been some news reports of Dino DNA, but the ones I’ve seen have been discredited. [Happens a lot with feathers.](http://news.discovery.com/animals/dinosaurs/dinosaurs-feathers-amber-photos-110915.htm) (That’s preserved in amber, but I know that there’s been some feather material recovered from more ‘traditional’ type fossils…I just can’t find an article about it.) [Some blood was also isolated earlier this year.](http://news.discovery.com/animals/dinosaurs/dinosaur-blood-and-skin-cells-found-photos-150609.htm) Note that this is not DNA. What they’re finding are things like keratin, melanin etc. Things that allow evidence of the presence and colour of specific types of integument, or just ‘holy shit, soft tissues!’. ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [December 21, 2015, 2:39pm UTC](https://boards.straightdope.com/t/dinosaur-extinction/740940/29 "2015-12-21T14:39:25Z")
> [@Kamino\_Neko](#): > > [Happens a lot with feathers.](http://news.discovery.com/animals/dinosaurs/dinosaurs-feathers-amber-photos-110915.htm) (That’s preserved in amber, but I know that there’s been some feather material recovered from more ‘traditional’ type fossils…I just can’t find an article about it.) > > [Some blood was also isolated earlier this year.](http://news.discovery.com/animals/dinosaurs/dinosaur-blood-and-skin-cells-found-photos-150609.htm) > > Note that this is not DNA. What they’re finding are things like keratin, melanin etc. Things that allow evidence of the presence and colour of specific types of integument, or just ‘holy shit, soft tissues!’. Yep, there are a number of instances when “soft tissue” has been discovered, but no Dino DNA. We need to keep in mind that _Jurassic Park_ was not a documentary. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [December 21, 2015, 2:59pm UTC](https://boards.straightdope.com/t/dinosaur-extinction/740940/30 "2015-12-21T14:59:40Z")
> [@md2000](#): > > One thing I read said that ALL large creatures died, from the initial blast or loss of food sources. One article suggested anything over about 5 pounds died, another said about 20 pounds. That doesn’t leave behind a lot, but ever seen baby alligators? Or turtles? Presumably some mammals the size of a mouse also survived…buried seeds, or small animals washed over by flood waves to prevent the heat shock presumably provided the basis for a gradual rebuild of thee ecology. I’ve been having trouble finding the reference, but I’ve seen statements that for several million years after the event the largest land animal was no larger than a large dog. (I don’t think I’ve ever seen a reference saying the limit was five pounds - maybe five kilos.) > [@Urbanredneck](#): > > I’ve always wondered why that in the hundreds of millions of years dinosaurs were on the world, that a sentient or smart dinosaur didnt develop? Why havent we found a dinosaur fossil holding a clay pot? Certainly some dinosaurs had opposable thumbs, a large brain, and binocular vision. We vastly overrate the value of intelligence as a evolutionary benefit because it’s our own distinguishing feature. If it were more valuable, surely it would have developed multiple times, and much earlier in evolutionary history, like flight, running speed, warm-bloodedness, etc. Even in our own lineage, the benefits of intelligence didn’t really become apparent until we reached the technological stage a few thousand years ago. We and our ancestors spent millions of years as by far the most intelligent species on the planet without it making us exceptionally successful compared animals with much less brain power. In fact, hominids have been pretty rare almost throughout their evolutionary history. ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [December 21, 2015, 3:08pm UTC](https://boards.straightdope.com/t/dinosaur-extinction/740940/31 "2015-12-21T15:08:10Z")
> [@Colibri](#): > > Even in our own lineage, the benefits of intelligence didn’t really become apparent until we reached the technological stage a few thousand years ago. We and our ancestors spent millions of years as by far the most intelligent species on the planet without it making us exceptionally successful compared animals with much less brain power. In fact, hominids have been pretty rare almost throughout their evolutionary history. Our ancestors were pretty successful compared to other ape species, though, since they colonized so many different climate zones not by adapting physically so much as using technology. But yeah, being a hunter/gatherer pretty much limits your total population size since you need so much more land per person to survive. If we look at other large mammalian carnivores, they tend not to be very numerous and we’d fit a similar pattern. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [December 21, 2015, 3:17pm UTC](https://boards.straightdope.com/t/dinosaur-extinction/740940/32 "2015-12-21T15:17:21Z")
> [@John\_Mace](#): > > Our ancestors were pretty successful compared to other ape species, though, since they colonized so many different climate zones not by adapting physically so much as using technology. Even after the acquisition of fire, probably by Homo erectus, allowed colonization of the temperate zone populations were still very sparse and probably often went locally extinct. But the relative lack of success of apes in general helps make my point as well. Despite being more intelligent than any other land animals, they have been declining in diversity and range ever since their peak in the Miocene. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [December 21, 2015, 3:31pm UTC](https://boards.straightdope.com/t/dinosaur-extinction/740940/33 "2015-12-21T15:31:44Z")
> [@Colibri](#): > > Despite being more intelligent than any other land animals, they have been declining in diversity and range ever since their peak in the Miocene. They did face competition from a more intelligent land animal. ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [December 21, 2015, 3:38pm UTC](https://boards.straightdope.com/t/dinosaur-extinction/740940/34 "2015-12-21T15:38:20Z")
> [@TriPolar](#): > > They did face competition from a more intelligent land animal. Only very recently. We’ve been causing an alarmingly accelerate decline in ape populations, but they were not all that numerous even 100,000 years ago. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [December 21, 2015, 3:48pm UTC](https://boards.straightdope.com/t/dinosaur-extinction/740940/35 "2015-12-21T15:48:56Z")
> [@John\_Mace](#): > > Only very recently. We’ve been causing an alarmingly accelerate decline in ape populations, but they were not all that numerous even 100,000 years ago. My understanding was that our ancestors had diverged from the apes by the end of the Miocene, and not initially in great numbers either. There may be much more to consider but the general image I have is that both groups were not hugely successful for a long time until our ancestors broke out and began to dominate, and both groups would have been competing in for similar resources during that time. I think to some degree that competition would have narrowed opportunities for the apes, and much more so as hominids became successful. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [December 21, 2015, 3:51pm UTC](https://boards.straightdope.com/t/dinosaur-extinction/740940/36 "2015-12-21T15:51:16Z")
> [@TriPolar](#): > > They did face competition from a more intelligent land animal. What would that be? If you are referring to our own ancestors, they were apes as well (as we are) and weren’t any more intelligent than other apes for most of that time. ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [December 21, 2015, 3:57pm UTC](https://boards.straightdope.com/t/dinosaur-extinction/740940/37 "2015-12-21T15:57:22Z")
> [@TriPolar](#): > > My understanding was that our ancestors had diverged from the apes by the end of the Miocene, and not initially in great numbers either. There may be much more to consider but the general image I have is that both groups were not hugely successful for a long time until our ancestors broke out and began to dominate, and both groups would have been competing in for similar resources during that time. I think to some degree that competition would have narrowed opportunities for the apes, and much more so as hominids became successful. I don’t know that you could call our ancestors a “more intelligent land animal” until they weren’t living in the forests any longer, and wouldn’t have been competing with chimps or gorillas. And, of course, we never competed with orangutans until we left Africa. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [December 21, 2015, 3:58pm UTC](https://boards.straightdope.com/t/dinosaur-extinction/740940/38 "2015-12-21T15:58:33Z")
> [@Colibri](#): > > What would that be? > > If you are referring to our own ancestors, they were apes as well (as we are) and weren’t any more intelligent than other apes for most of that time. On that basis we have no argument. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [December 21, 2015, 4:03pm UTC](https://boards.straightdope.com/t/dinosaur-extinction/740940/39 "2015-12-21T16:03:44Z")
> [@John\_Mace](#): > > I don’t know that you could call our ancestors a “more intelligent land animal” until they weren’t living in the forests any longer, and wouldn’t have been competing with chimps or gorillas. And, of course, we never competed with orangutans until we left Africa. We’re going off topic now, but briefly, in order for the forest apes to become more successful they would have had to venture out of the forests as well where they would have faced our ancestors who were then more intelligent. However, using Colibri’s definition which groups our ancestors and apes together neither was very successful for a long time. But you make a good point about orangs, they weren’t facing any such competition for a long time and pretty much had a lock on the intelligent primate market in Asia that they didn’t take advantage of. Just another plug for the advantage of competition. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [December 21, 2015, 4:19pm UTC](https://boards.straightdope.com/t/dinosaur-extinction/740940/40 "2015-12-21T16:19:16Z")
There were at least three lines of hominids who reached the point of making and using tools (things like clay and flint): Us, Neanderthals, and Floresiens. Granted that we’re all three pretty closely related, but how smart was the most recent ancestor of those three? Did the big jump happen once, from chimplike intelligence to that creature, or did it happen three times, from that creature to the three tool-users? [Previous page](https://boards.straightdope.com/t/dinosaur-extinction/740940.md?page=1) [Next page](https://boards.straightdope.com/t/dinosaur-extinction/740940.md?page=3)