D&D General Tyrannosaurs were pack hunters. Stay away from the Isle of Dread.

[dave2008]

Anyway for the Isle of Dread you only need one large female and a couple of young to fill the T Rex quota without them depleting the islands meat sources

Sounds like I need to make a young T-Rex stat block then! I already have an upgrade Tyrannosaurus and Tyrannosaurus Alpha, might as well make a full pack!

 

[Oofta]

It’s scary enough now knowing elephants, whole heards, could easily pass a group stealth check against me. I refuse to attach that idea to T-Rex packs. Just for my own sanity.

How do you know if the DM is pissed at you? When a T Rex ambushes you while you're walking past a bush.

 

[dave2008]

That article is absurd. Scientists have been suggesting that, based on the exact same evidence from albertosaurs in the Dinosaur Provincial Park and large carnosaurs like Mapusaurus in Argentina for the better part of fifty years now. For the journalist to say that this discovery challenges long-held beliefs is flat out wrong. What it does is offer slight circumstantial evidence to support long-held beliefs, which are the exact opposite of what the journalist is saying that they are. And although that's been suggested, it certainly hasn't been proved; crocodiles hang out together and would fossilize in gangs or mobs similar to this as well if there was a sudden flash flood or ashfall that killed them together, but that hardly means that crocodiles are pack hunters. The jury is still very much out on whether or not tyrannosaurs and other large dinosaurian carnivores hunted in packs or not. But it's a new idea? C'mon. It was an old idea already when Nigel Marvin dramatized it in the mainstream BBC documentary Chased by Dinosaurs in 2002 for Giganotosaurus, and again specifically for T. rex in Prehistoric Park in 2006. I can understand why someone may not be familiar with those big, mainstream, docudramas if you're not a dinosaur fan, I guess, but how does a journalist say that a mainstream opinion that hasn't been current for decades is still the mainstream opinion. I mean, fer cryin' out loud, Bob Bakker's popular book Dinosaur Heresies suggested it in 1986, and that book was criticized by dinosaur scientists for doing the same thing for dramatic effect; pretending that these ideas that had started toppling during the late 60s and 70s were still current mainstream ideas about dinosaur behavior and biology when they weren't any more. Greg Paul's popular book Predatory Dinosaurs of the World basically made the assumption that it was a given that large predatory dinosaurs hunted in packs, and that book was written in 1988 and was cited as a major influence on Michael Crichton's own Jurassic Park novel. It's a perfect example, speaking of Michael Crichton, of why he coined the Gell-Mann amnesia effect. "Briefly stated, the Gell-Mann Amnesia effect is as follows. You open the newspaper to an article on some subject you know well. In Murray's case, physics. In mine, show business. You read the article and see the journalist has absolutely no understanding of either the facts or the issues. Often, the article is so wrong it actually presents the story backward—reversing cause and effect. I call these the 'wet streets cause rain' stories. Paper's full of them. In any case, you read with exasperation or amusement the multiple errors in a story, and then turn the page to national or international affairs, and read as if the rest of the newspaper was somehow more accurate about Palestine than the baloney you just read. You turn the page, and forget what you know. That is the Gell-Mann Amnesia effect. I'd point out it does not operate in other arenas of life. In ordinary life, if somebody consistently exaggerates or lies to you, you soon discount everything they say. In court, there is the legal doctrine of falsus in uno, falsus in omnibus, which means untruthful in one part, untruthful in all. But when it comes to the media, we believe against evidence that it is probably worth our time to read other parts of the paper. When, in fact, it almost certainly isn't. The only possible explanation for our behavior is amnesia.”

Wow, none of that is really relevant to the Isle of Dread or D&D though. Regardless it was an interesting post and thank you for sharing.

However

3) T. rexes weren't at all closely related to elephants. What they were more closely related to is large birds. There are no featherless large birds, no matter how tropical the environment that they lived in, as far as we know. Moas and elephant birds weren't featherless. Ostriches aren't featherless. Nobody is suggesting that phorusrachids or gastornids were featherless, even though some of them (particularly the latter) lived in even hotter times than the Cretaceous. In fact, we may even have a Gastornis feather impression from the Green River formation. T. rex's ancestors were certainly feathered, like Yutyrannus, which was a pretty sizeable animal itself; maybe not as massive as an elephant, but more massive than most rhinos, and Yutyrannus was certainly feathered. Of course, to be fair, the climate was probably a bit more temperate where Yutyrannus lived, and they may have had pretty frosty weather in the winter. But it's not a binary case of "T. rex had to live at the poles, otherwise it wouldn't have needed or had feathers" which seems a bit close to what's being proposed here. By the way, we also know other large dinosaurs, even in very tropical climates, were feathered, like big oviraptors and therizinosaurs.

Anyway, all of that presupposes that you want "accurate" dinosaurs in your D&D, which is hardly a given.

None of the assumed T-Rex skin impressions have feathers and most current science I have seen on the subject believe T-Rex was probably featherless. Of course, this is again not relevant to D&D and/or the Isle of Dread.

 

[dave2008]

So yes, I think The Isle of Dread is too small.

To small for "reality" maybe. To small for fantasy island dinos, certainly not.

 

[Frozen_Heart]

Though no large modern birds are featherless, no large modern birds even come close to the mass of a rhino or hippo, let alone an elephant. Even elephant birds and gastornis would weigh about as much as a horse (birds and dinosaurs are a lot less dense than mammals).

Tyrannosaurus on the other hand would be extremely similar in mass to a large elephant, and so makes a lot more sense to compare to when assuming how much heat it would have to lose. Though we also know that its ancestors definitely did have feathers. There is also the question of its metabolism. How much heat did it produce, and how much did it get from its environment? Both mammals and birds and endotherms, but we're unsure where most dinosaurs were. Different species probably varied immensely.

Therizinosaurus is another difficult one. There is no direct evidence for feathers, but its ancestors definitely had them. It's also less massive than rex, though still extremely large and lived in a hot climate.

Mentioning theri... wonder what its stat block and CR would be?

 

[dave2008]

I follow paleontology fairly closely (as an amateur), and one thing that I learned a while back is that many big carnivores like T-rex not only hunted in packs, but actually had different ecological roles based on their age. Younger animals grew fast but were much lighter and leaner, while full-grown adults (like the Sue skeleton belonged to) were enormously robust and powerful. So you had the younger ones acting as sheepdogs almost, herding prey, rounding them up and nipping at their heels and hamstrings, while the big brawny adults closed in for the kill.

Which would be complete overkill for human-sized prey of course! But you could easily justify different stat line variants for the different age groups, perhaps one with 10ft more speed and one with a higher Str...

To be clear, we have very little to no evidence of this behavior. It is reasonable speculation, but it is not scientifically accurate to say we know how an animal that died out 65 million years ago behaved. Heck, we still have disagreements on how heavy and fast they were!

Also, the science of paleontology has had some rather suspect characters who don't always do the best "science." Example A: Jack Horner.

I remember watching a documentary with him in the 80s discussing whether T-Rex as a scavenger vs. a predatory. He was on the scavenger side. His main evidence was that he couldn't imagine T-Rex coming away from a battle with a Triceratops with anything but "...a mouth full of broken teeth." Years later some material scientist showed the T-Rex had extremely robust teeth, more robust than other carnivorous dinosaurs and more robust (pound-for-pound) than modern predatory mammals and others indicated it probably had the bite force to crush bone. So what did Jack do with this evidence that contradicted what he "imagined" a few years earlier. He determined that this evidence actually supported the idea that T-Rex was an obligate scavenger because it can crush bones "like a hyena." Of course hyena's are not scavengers either, but you know Jack isn't the best with science and facts. However, his sensationalism did get him a gig as the "expert" for the JP movies. Sorry for the rant, that man drives me crazy.

 

[Mind of tempest]

Though no large modern birds are featherless, no large modern birds even come close to the mass of a rhino or hippo, let alone an elephant. Even elephant birds and gastornis would weigh about as much as a horse (birds and dinosaurs are a lot less dense than mammals).

Tyrannosaurus on the other hand would be extremely similar in mass to a large elephant, and so makes a lot more sense to compare to when assuming how much heat it would have to lose. Though we also know that its ancestors definitely did have feathers. There is also the question of its metabolism. How much heat did it produce, and how much did it get from its environment? Both mammals and birds and endotherms, but we're unsure where most dinosaurs were. Different species probably varied immensely.

Therizinosaurus is another difficult one. There is no direct evidence for feathers, but its ancestors definitely had them. It's also less massive than rex, though still extremely large and lived in a hot climate.

Mentioning theri... wonder what its stat block and CR would be?

a brutal claw attack but mostly slow-moving leaf eater likely size large lots of hp and at least a basic armour class of above 11.

 

[Steampunkette]

Though no large modern birds are featherless, no large modern birds even come close to the mass of a rhino or hippo, let alone an elephant. Even elephant birds and gastornis would weigh about as much as a horse (birds and dinosaurs are a lot less dense than mammals).

Tyrannosaurus on the other hand would be extremely similar in mass to a large elephant, and so makes a lot more sense to compare to when assuming how much heat it would have to lose. Though we also know that its ancestors definitely did have feathers. There is also the question of its metabolism. How much heat did it produce, and how much did it get from its environment? Both mammals and birds and endotherms, but we're unsure where most dinosaurs were. Different species probably varied immensely.

Therizinosaurus is another difficult one. There is no direct evidence for feathers, but its ancestors definitely had them. It's also less massive than rex, though still extremely large and lived in a hot climate.

Mentioning theri... wonder what its stat block and CR would be?

Worth noting: Scale impression fossilization (Not actual skin/scales but where the scales pressed against mud which hardened over time) show fairly clearly that T-Rex and other Tyrannosauridae did not have full-coverage feathers as adults. Whether this was because of the temperature of the world at the time, the amount of heat they generated or retained, and otherwise is kinda moot.

Though they -may- have had incomplete coverage... it's really a matter of slowly walking back the idea of feathered T-Rex inch by inch as it's much more likely they had no feathers.

Though I, for one, would still like to imagine baby T-rexes as having feathers that they slowly grow out of except for a feathered crest along their head, neck, and back, for mating displays. Just 'cause a giant murdersaur doing a wiggly little feather-tossing dance to entice a mate is hilarious and giant baby chickens with teeth are adorably terrifying.

 

[Sacrosanct]

Super stealthy packs of T rex's? What next? Lasers? Feels like the 80s all over again

 

[Umbran]

3) T. rexes weren't at all closely related to elephants. What they were more closely related to is large birds. There are no featherless large birds, no matter how tropical the environment that they lived in, as far as we know.

The issue isn't genetic relation. The issue is thermodynamic similarity. The square-cube law can be a killer.

Ostriches weigh up to 320 pounds. Moas up to 550. Elephant birds weigh in around 1000 lbs. So far, nothing on the list is heavier than a bison. Rare indeed is the mammal species in this range that has gone hairless, so you'd not expect birds that large to be featherless.

Cattle come in at about a ton. Rhinos come in between one and and 2.5 tons. Elephants come in between 3 and 6.5 tons. An order of magnitude more than most of those birds. At this size, some species are largely hairless (modern elephants) and some not - mastodons, mammoths, and woolly rhinos. These creatures are starting to have issues losing heat, and sometimes lose the thick hair.

The T-rex comes in at 5 to 9 tons. The heat issue will be greater. While there may be feathers, you probably no longer expect a thick coat of them in warm climates.

In fact, we may even have a Gastornis feather impression from the Green River formation.

Yes. But "a feather impression" doesn't mean the beast was fully-feathered like a modern bird, any more than a hair impression means humans are furred like bears. An impression doesn't give you the pattern on the body.

By the way, we also know other large dinosaurs, even in very tropical climates, were feathered, like big oviraptors and therizinosaurs.

The largest oviraptor is estimated to have weighed in around 4000 lbs - this is rhino-sized, so not yet at the point where we are sure the insulation would be an issue.