# Is it possible some Dinosaurs still existed during the Dark Ages? **URL:** \ **Category:** Factual Questions\ **Created:** [August 4, 2017, 8:08pm UTC](https://boards.straightdope.com/t/is-it-possible-some-dinosaurs-still-existed-during-the-dark-ages/792800 "2017-08-04T20:08:57Z")\ **Posts on this page:** 20\ **Page:** 7
**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:** [August 7, 2017, 2:05pm UTC](https://boards.straightdope.com/t/is-it-possible-some-dinosaurs-still-existed-during-the-dark-ages/792800/121 "2017-08-07T14:05:32Z")
> [@Bricker](#): > > Huh? I’m about to learn something new. I was unaware that the rainforest was ever heavily populated with agriculturalists. When? What changed? > [@Darren\_Garrison](#): > > [Cite](https://www.scientificamerican.com/article/lost-amazon-cities/). [Cite](https://www.newscientist.com/article/dn27945-myth-of-pristine-amazon-rainforest-busted-as-old-cities-reappear/). Careful. Most people don’t know that the Amazon was dotted with populous, agricultural communities in pre-Columbian times, but “The Brazilian Rainforest” encompasses a lot of area that isn’t part of that same Amazonian ecosystem. ---
**Author:** ![MrDibble](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mrdibble/32/114_2.png) [@MrDibble](https://boards.straightdope.com/u/MrDibble)\ **Post date:** [August 7, 2017, 2:39pm UTC](https://boards.straightdope.com/t/is-it-possible-some-dinosaurs-still-existed-during-the-dark-ages/792800/122 "2017-08-07T14:39:11Z")
Google "The Brazilian Rainforest. [This](https://en.wikipedia.org/wiki/Amazon_rainforest) is the first hit (for me). Yes, there are other rainforests in Brazil. They were also occupied. ---
**Author:** ![MrDibble](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mrdibble/32/114_2.png) [@MrDibble](https://boards.straightdope.com/u/MrDibble)\ **Post date:** [August 7, 2017, 2:40pm UTC](https://boards.straightdope.com/t/is-it-possible-some-dinosaurs-still-existed-during-the-dark-ages/792800/123 "2017-08-07T14:40:39Z")
> [@Bricker](#): > > Huh? I’m about to learn something new. I was unaware that the rainforest was ever heavily populated with agriculturalists. When? What changed? Smallpox and measles, probably. ---
**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:** [August 7, 2017, 3:14pm UTC](https://boards.straightdope.com/t/is-it-possible-some-dinosaurs-still-existed-during-the-dark-ages/792800/124 "2017-08-07T15:14:40Z")
> [@MrDibble](#): > > Smallpox and measles, probably. Yeah, we’ve covered this before. Those infectious diseases spread faster than the Conquistadors and other European explorers, so by the time the Europeans entered all of the Americas, it looked very sparsely settled. But some estimates put the deaths of Native populations at 90%. And, as most of us are aware, there are still some “uncontacted” people in the Amazon basin. ---
**Author:** ![Fotheringay-Phipps](https://avatars.discourse-cdn.com/v4/letter/f/d9b06d/32.png) [@Fotheringay-Phipps](https://boards.straightdope.com/u/Fotheringay-Phipps)\ **Post date:** [August 7, 2017, 3:16pm UTC](https://boards.straightdope.com/t/is-it-possible-some-dinosaurs-still-existed-during-the-dark-ages/792800/125 "2017-08-07T15:16:52Z")
> [@engineer\_comp\_geek](#): > > 65 million years ago, a big chunk of rock smashed down on what is now known as the Yucatan Peninsula in Mexico with enough force that debris from the impact itself rained down as far north as Kentucky. More hot debris from the impact was thrown so high into the atmosphere that it ended up raining fire down all over the globe. Everywhere on earth, there is a layer of carbon corresponding to that date, meaning that the entire earth burned. Not just part of it, not just the area near the impact, the entire earth. > > In other words, it was basically hell on earth. > > Most things died. Not only most things, but most species died. The species that survived had most of their members killed, but managed to have enough survive to maintain viable populations. > > Most of the survivors were small creatures that don’t need a lot of food to survive. Plant eaters (the few that hadn’t been cooked to death) no longer had plants to eat, though some tiny sprouts certainly grew out of the ashes. Anything big enough that it required more than a few tiny sprouts here and there starved to death. The meat eaters (again, those few that hadn’t been cooked to death) at first had a field day. Lots and lots of pre-cooked food everywhere! What a feast. Eventually though, they ran out of dead bodies, and with the surviving plant eaters dying off, the carnivores starved to death as well. > > The largest things that survived were a few variants of crocodiles, which could submerge for reasonably long periods of time to avoid getting roasted in the initial flames. They could also go for long periods of time without eating, which enabled them to survive while other species starved to death. > > Nothing big that flew survived. > > Nothing bigger than a crocodile survived. In fact, few things bigger than a mouse survived. > > Creatures in the ocean fared a bit better, since most of them weren’t burned to death after the impact. A lot of stuff in the ocean ended up dying as well though, which indicates that even after the initial fires died down, the Earth wasn’t a happy place to be, most likely suffering through decades of severe cold caused by sunlight being blocked by stuff thrown up from the impact combined with all kinds of stuff from volcanic eruptions. A rock that big slamming into the earth makes some pretty big shock waves, which cause earthquakes and tsunamis and triggers lots of volcanic eruptions, especially on the other side of the earth from the impact (called the antipodal point) due to the shock waves all converging on that point. > > You almost have to wonder how anything at all survived. It was pretty nasty. The problem with writing this in the context of this thread is that there’s not nearly as much certainty about this hypothesis as would be implied by its use in this context. ---
**Author:** ![Darwins\_Finch](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darwins_finch/32/20304_2.png) [@Darwins\_Finch](https://boards.straightdope.com/u/Darwins_Finch)\ **Post date:** [August 7, 2017, 4:31pm UTC](https://boards.straightdope.com/t/is-it-possible-some-dinosaurs-still-existed-during-the-dark-ages/792800/126 "2017-08-07T16:31:44Z")
> [@Bricker](#): > > Is it absolutely impossible that there’s a small, neat-extinct population of Aquilops in the Brazilian rainforest? Yes. _Aquilops_ is a genus containing one know species: _A. americanus_. The typical lifespan of a species is not generally more than 10 million years; thus, one can say that it is literally impossible for there to be any surviving members of _A. americanus_; no species sticks around for 100 million years. No population remains static for an extended time (in geological terms). By necessity, even if _Aquilops_ lineage continued, its descendants would differ enough from _A. americanus_ that they would be placed in a different species; very likely, in a different genus, as well, since the population would have had to adapt to numerous environmental changes over the course of 100 million years +. So, I can confidently claim that, even if a small population of ceratopsian dinosaurs were found to be extant, they would absolutely not belong to _Aquilops_. ---
**Author:** ![Bricker](https://avatars.discourse-cdn.com/v4/letter/b/977dab/32.png) [@Bricker](https://boards.straightdope.com/u/Bricker)\ **Post date:** [August 7, 2017, 5:09pm UTC](https://boards.straightdope.com/t/is-it-possible-some-dinosaurs-still-existed-during-the-dark-ages/792800/127 "2017-08-07T17:09:55Z")
> [@MrDibble](#): > > Google "The Brazilian Rainforest. [This](https://en.wikipedia.org/wiki/Amazon_rainforest) is the first hit (for me). Yes, there are other rainforests in Brazil. They were also occupied. Well, news to me! OK, forget the rainforest. Unknown to me, it was a veritable metropolis at one time. How about an ecological island like one of the South American tepuis? ---
**Author:** ![Bricker](https://avatars.discourse-cdn.com/v4/letter/b/977dab/32.png) [@Bricker](https://boards.straightdope.com/u/Bricker)\ **Post date:** [August 7, 2017, 5:17pm UTC](https://boards.straightdope.com/t/is-it-possible-some-dinosaurs-still-existed-during-the-dark-ages/792800/128 "2017-08-07T17:17:56Z")
> [@Darwins\_Finch](#): > > Yes. _Aquilops_ is a genus containing one know species: _A. americanus_. The typical lifespan of a species is not generally more than 10 million years; thus, one can say that it is literally impossible for there to be any surviving members of _A. americanus_; no species sticks around for 100 million years. > > No population remains static for an extended time (in geological terms). By necessity, even if _Aquilops_ lineage continued, its descendants would differ enough from _A. americanus_ that they would be placed in a different species; very likely, in a different genus, as well, since the population would have had to adapt to numerous environmental changes over the course of 100 million years +. > > So, I can confidently claim that, even if a small population of ceratopsian dinosaurs were found to be extant, they would absolutely not belong to _Aquilops_. I’m not trying to be difficult, here; this is not my field. I have questions. When we talk about crocodiles being unchanged for 100 million years or more, I’m not sure I understand how that squares with your declaration that after 10 million, no dice. I asked about the genus, not the species[sup]\*[/sup], so I’m not sure when we switched to _A. americanus_ as opposed to more generically some heretofore unknown species of _Aquilops_. But I’m sure it’s because I’m missing some distinction that’s obvious. Help me? - A distinction I remember from high school. King Phillip Couldn’t Order Fresh Ground Steak. ---
**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:** [August 7, 2017, 5:23pm UTC](https://boards.straightdope.com/t/is-it-possible-some-dinosaurs-still-existed-during-the-dark-ages/792800/129 "2017-08-07T17:23:56Z")
> [@Bricker](#): > > I’m not trying to be difficult, here; this is not my field. I have questions. > > When we talk about crocodiles being unchanged for 100 million years or more, I’m not sure I understand how that squares with your declaration that after 10 million, no dice. I asked about the genus, not the species, so I’m not sure when we switched to _A. americanus_ as opposed to more generically some heretofore unknown species of _Aquilops_. > > But I’m sure it’s because I’m missing some distinction that’s obvious. Help me? We don’t know that crocodiles haven’t changed in 100 millions years. We see superficial characteristics that are similar for much longer time periods but we assume they’ve changed a great deal in that time. If Aquilops survived the extinction event we would expect them to be different by now (or if they finally died out after a million or so years). ---
**Author:** ![gytalf2000](https://avatars.discourse-cdn.com/v4/letter/g/ac91a4/32.png) [@gytalf2000](https://boards.straightdope.com/u/gytalf2000)\ **Post date:** [August 7, 2017, 5:32pm UTC](https://boards.straightdope.com/t/is-it-possible-some-dinosaurs-still-existed-during-the-dark-ages/792800/130 "2017-08-07T17:32:35Z")
> [@Go\_Arachnid\_Laser](#): > > I don’t know medieval knights would even notice a dinosaur- they were too busy in their war against [GIANT SNAILS.](https://www.google.es/search?q=knights+giant+snails&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiLs5ij-L_VAhVGuhoKHVu5AL8Q_AUICigB&biw=1536&bih=751) Hilarious pics! I had no idea… ---
**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:** [August 7, 2017, 5:33pm UTC](https://boards.straightdope.com/t/is-it-possible-some-dinosaurs-still-existed-during-the-dark-ages/792800/131 "2017-08-07T17:33:21Z")
> [@Bricker](#): > > I’m not trying to be difficult, here; this is not my field. I have questions. > > When we talk about crocodiles being unchanged for 100 million years or more, I’m not sure I understand how that squares with your declaration that after 10 million, no dice. I asked about the genus, not the species[sup]_[/sup], so I’m not sure when we switched to A. americanus as opposed to more generically some heretofore unknown s_\*\*\*pecies of _Aquilops_. > > But I’m sure it’s because I’m missing some distinction that’s obvious. Help me? > > - A distinction I remember from high school. King Phillip Couldn’t Order Fresh Ground Steak. We talk about the phenotype of crocs showing little change over a long period of time. We don’t have any croc DNA from 100M years ago, so we wouldn’t know definitively, but we do know that genotypes change over time, so we expect that to have happened regardless of the phenotype. Plus, it’s very dodgy talking about extinct species since we define species as populations that generally do not interbreed even when they occupy the same territory. When populations are separated temporally, we use our best estimate to determine if they were separate species or not, and by that we usually have to rely on morphological analysis instead of DNA analysis. But as **DF** already said, we don’t expect a species to remain the same species for 100M years. ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [August 7, 2017, 5:41pm UTC](https://boards.straightdope.com/t/is-it-possible-some-dinosaurs-still-existed-during-the-dark-ages/792800/132 "2017-08-07T17:41:56Z")
> [@Bricker](#): > > How about an ecological island like one of the South American tepuis? Also extensively explored. The weirdest thing up there is [these](https://www.flytrapcare.com/heliamphora). ---
**Author:** ![Fotheringay-Phipps](https://avatars.discourse-cdn.com/v4/letter/f/d9b06d/32.png) [@Fotheringay-Phipps](https://boards.straightdope.com/u/Fotheringay-Phipps)\ **Post date:** [August 7, 2017, 5:42pm UTC](https://boards.straightdope.com/t/is-it-possible-some-dinosaurs-still-existed-during-the-dark-ages/792800/133 "2017-08-07T17:42:54Z")
> [@Darwins\_Finch](#): > > Yes. _Aquilops_ is a genus containing one know species: _A. americanus_. The typical lifespan of a species is not generally more than 10 million years; thus, one can say that it is literally impossible for there to be any surviving members of _A. americanus_; no species sticks around for 100 million years. > > No population remains static for an extended time (in geological terms). By necessity, even if _Aquilops_ lineage continued, its descendants would differ enough from _A. americanus_ that they would be placed in a different species; very likely, in a different genus, as well, since the population would have had to adapt to numerous environmental changes over the course of 100 million years +. > > So, I can confidently claim that, even if a small population of ceratopsian dinosaurs were found to be extant, they would absolutely not belong to _Aquilops_. This seems somewhat circular to me. The reason a species would have to change over the millions of years is because the original version wasn’t adapted to the changing environment, and needed to change to survive. But if there was some exception to this - if there was some rare instance of a species which could survive in a unusually broad variety of environments - then it could survive without changes for far longer than the 10 million. The entire question in the OP was whether there might be some such rare exception. You can’t answer that question by pointing to the general rules that are based on the vast majority of species. The OP accepted the obvious premise that there are very few if any species of dinosaur in the world. The question was whether we can definitively say that there are zero. I don’t see what you’re bringing to bear on that question other than to say, effectively, that “there can’t be an exception because the vast majority are otherwise”, which makes no logical sense. ---
**Author:** ![Darwins\_Finch](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darwins_finch/32/20304_2.png) [@Darwins\_Finch](https://boards.straightdope.com/u/Darwins_Finch)\ **Post date:** [August 7, 2017, 5:43pm UTC](https://boards.straightdope.com/t/is-it-possible-some-dinosaurs-still-existed-during-the-dark-ages/792800/134 "2017-08-07T17:43:16Z")
> [@Bricker](#): > > I’m not trying to be difficult, here; this is not my field. I have questions. > > When we talk about crocodiles being unchanged for 100 million years or more, I’m not sure I understand how that squares with your declaration that after 10 million, no dice. I asked about the genus, not the species, so I’m not sure when we switched to _A. americanus_ as opposed to more generically some heretofore unknown species of _Aquilops_. > > But I’m sure it’s because I’m missing some distinction that’s obvious. Help me? It’s because people are looking at different taxonomic levels. “Crocodiles” is a broad group, encompassing many genera and species, over a very long period of time. The basic crocodile shape has not been altered much by evolution - the environmental demands of a fresh-water ambush-predator reptile remain largely the same today as they were 100 million years ago. But, the small morphological changes build up over time, such that existing species of crocodile are not the same as extinct species. The overall body plan remains the same, but the details do not. In terms of Linnaean taxonomy, “crocodiles” represents an entire Order, composed of different Families, Genera and species. As for the switch from genus to species, many dinosaur names are coined with both a new genus and species (oftentimes, a re-evaluation will place several previously-distinct genera and species into one genus). What we know as “Aquilops” is one single species, _Aquilops americanus_. That species would have lasted no longer than 10 million years; probably fewer. _Aquilops_ as a genus might have persisted for a while longer, but after 100 million years and at least one catastrophic extinction event, any survivors would have faced a different enough world, with its concomitant changes in adaptive pressures, that they would be unlikely to be classified as the same genus, though they would still be ceratopsian descendants of _Aquilops_. Even the “newly discovered to be extant” coelocanths were placed in a genus distinct from the fossil versions, after all. ---
**Author:** ![Bone](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bone/32/407_2.png) [@Bone](https://boards.straightdope.com/u/Bone)\ **Post date:** [August 7, 2017, 5:47pm UTC](https://boards.straightdope.com/t/is-it-possible-some-dinosaurs-still-existed-during-the-dark-ages/792800/135 "2017-08-07T17:47:38Z")
> [@engineer\_comp\_geek](#): > > 65 million years ago, a big chunk of rock smashed down on what is now known as the Yucatan Peninsula in Mexico with enough force that debris from the impact itself rained down as far north as Kentucky. More hot debris from the impact was thrown so high into the atmosphere that it ended up raining fire down all over the globe. Everywhere on earth, there is a layer of carbon corresponding to that date, meaning that the entire earth burned. Not just part of it, not just the area near the impact, the entire earth. > > In other words, it was basically hell on earth. > > Most things died. Not only most things, but most species died. The species that survived had most of their members killed, but managed to have enough survive to maintain viable populations. > > Most of the survivors were small creatures that don’t need a lot of food to survive. Plant eaters (the few that hadn’t been cooked to death) no longer had plants to eat, though some tiny sprouts certainly grew out of the ashes. Anything big enough that it required more than a few tiny sprouts here and there starved to death. The meat eaters (again, those few that hadn’t been cooked to death) at first had a field day. Lots and lots of pre-cooked food everywhere! What a feast. Eventually though, they ran out of dead bodies, and with the surviving plant eaters dying off, the carnivores starved to death as well. > > The largest things that survived were a few variants of crocodiles, which could submerge for reasonably long periods of time to avoid getting roasted in the initial flames. They could also go for long periods of time without eating, which enabled them to survive while other species starved to death. > > Nothing big that flew survived. > > Nothing bigger than a crocodile survived. In fact, few things bigger than a mouse survived. > > Creatures in the ocean fared a bit better, since most of them weren’t burned to death after the impact. A lot of stuff in the ocean ended up dying as well though, which indicates that even after the initial fires died down, the Earth wasn’t a happy place to be, most likely suffering through decades of severe cold caused by sunlight being blocked by stuff thrown up from the impact combined with all kinds of stuff from volcanic eruptions. A rock that big slamming into the earth makes some pretty big shock waves, which cause earthquakes and tsunamis and triggers lots of volcanic eruptions, especially on the other side of the earth from the impact (called the antipodal point) due to the shock waves all converging on that point. > > You almost have to wonder how anything at all survived. It was pretty nasty. Remind me not to have you read bedtime stories to the little kids 🙂 ---
**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:** [August 7, 2017, 5:49pm UTC](https://boards.straightdope.com/t/is-it-possible-some-dinosaurs-still-existed-during-the-dark-ages/792800/136 "2017-08-07T17:49:44Z")
> [@Darwins\_Finch](#): > > Even the “newly discovered to be extant” coelocanths were placed in a genus distinct from the fossil versions, after all. Correct me if I’m wrong about this, but for animals, there is an official body of scientist that determine species designation for populations, but all the higher levels of classification are not supervised in the same way, so we have to rely on consensus to determine which is which. And my understanding is for extant species. Is that also true for extinct populations? ---
**Author:** ![Bricker](https://avatars.discourse-cdn.com/v4/letter/b/977dab/32.png) [@Bricker](https://boards.straightdope.com/u/Bricker)\ **Post date:** [August 7, 2017, 5:53pm UTC](https://boards.straightdope.com/t/is-it-possible-some-dinosaurs-still-existed-during-the-dark-ages/792800/137 "2017-08-07T17:53:35Z")
> [@Darwins\_Finch](#): > > It’s because people are looking at different taxonomic levels. “Crocodiles” is a broad group, encompassing many genera and species, over a very long period of time. The basic crocodile shape has not been altered much by evolution - the environmental demands of a fresh-water ambush-predator reptile remain largely the same today as they were 100 million years ago. But, the small morphological changes build up over time, such that existing species of crocodile are not the same as extinct species. The overall body plan remains the same, but the details do not. In terms of Linnaean taxonomy, “crocodiles” represents an entire Order, composed of different Families, Genera and species. > > As for the switch from genus to species, many dinosaur names are coined with both a new genus and species (oftentimes, a re-evaluation will place several previously-distinct genera and species into one genus). What we know as “Aquilops” is one single species, _Aquilops americanus_. That species would have lasted no longer than 10 million years; probably fewer. _Aquilops_ as a genus might have persisted for a while longer, but after 100 million years and at least one catastrophic extinction event, any survivors would have faced a different enough world, with its concomitant changes in adaptive pressures, that they would be unlikely to be classified as the same genus, though they would still be ceratopsian descendants of _Aquilops_. > > Even the “newly discovered to be extant” coelocanths were placed in a genus distinct from the fossil versions, after all. OK, thanks - this raises more questions, though, and I hope I’m not taxing your patience. Obviously there is seldom a bright dividing line, such that we could point to a female croc and say, “She’s species 1,” and her eggs will hatch into species 2 members. But at some point we theoretically reach the divide such that if I had a TARDIS and a croc wrangler, and I brought back a croc from 30 million years ago, it would not interbreed with current specimens. Is that accurate? Is the issue purely biological? I seem to remember reading about finches in a valley that were separated and became two species, unable to interbreed, but the issue was (I thought) social mating behavior more than biology. Or am I just conflating concepts? ---
**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:** [August 7, 2017, 6:00pm UTC](https://boards.straightdope.com/t/is-it-possible-some-dinosaurs-still-existed-during-the-dark-ages/792800/138 "2017-08-07T18:00:43Z")
> [@Bricker](#): > > s the issue purely biological? I seem to remember reading about finches in a valley that were separated and became two species, unable to interbreed, but the issue was (I thought) social mating behavior more than biology. Or am I just conflating concepts? All behavior is biological. 😃 But you are correct. Sometimes it’s behavior that prevents mating, and if that is the case, the populations will still be considered separate species. This will be true even if fertile offspring can be produced artificially. If it’s a physical barrier separating them, and they would interbreed if that barrier were removed, then they are considered to be subspecies. ---
**Author:** ![Darwins\_Finch](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darwins_finch/32/20304_2.png) [@Darwins\_Finch](https://boards.straightdope.com/u/Darwins_Finch)\ **Post date:** [August 7, 2017, 6:19pm UTC](https://boards.straightdope.com/t/is-it-possible-some-dinosaurs-still-existed-during-the-dark-ages/792800/139 "2017-08-07T18:19:53Z")
> [@John\_Mace](#): > > Correct me if I’m wrong about this, but for animals, there is an official body of scientist that determine species designation for populations, but all the higher levels of classification are not supervised in the same way, so we have to rely on consensus to determine which is which. > > And my understanding is for extant species. Is that also true for extinct populations? Strictly speaking, it’s all scientific consensus. The ICZN (International Code for Zoological Nomenclature) dictates rules for naming various taxonomic levels, but has nothing to say about what gets included in those levels. But, for example, if I coin a new Family name, then that Family is considered valid so long as I meet all the assorted requirements (dissemination method, not already in use, correct format, etc.). I can include 1 or 1000 species in that Family (of course, since most modern taxonomists deal with clades, who gets included will be defined by the clade itself, but it’s usually fairly arbitrarily defined as to which node gets what Linnaean category). ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [August 7, 2017, 6:27pm UTC](https://boards.straightdope.com/t/is-it-possible-some-dinosaurs-still-existed-during-the-dark-ages/792800/140 "2017-08-07T18:27:21Z")
> [@Darwins\_Finch](#): > > The basic crocodile shape has not been altered much by evolution Except for the [ones](http://www.smithsonianmag.com/science-nature/new-species-crocodiles-there-was-carolina-butcher-180954636/) [that](https://www.theguardian.com/science/2009/nov/19/galloping-dinosaur-eating-crocodiles) [were](http://news.nationalgeographic.com/news/2009/11/091119-dinosaurs-crocodiles-missions.html). [Previous page](https://boards.straightdope.com/t/is-it-possible-some-dinosaurs-still-existed-during-the-dark-ages/792800.md?page=6) [Next page](https://boards.straightdope.com/t/is-it-possible-some-dinosaurs-still-existed-during-the-dark-ages/792800.md?page=8)