# Could T-Rexes jump? **URL:** \ **Category:** Factual Questions\ **Created:** [January 7, 2015, 1:42am UTC](https://boards.straightdope.com/t/could-t-rexes-jump/709178 "2015-01-07T01:42:29Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![chacoguy](https://avatars.discourse-cdn.com/v4/letter/c/50afbb/32.png) [@chacoguy](https://boards.straightdope.com/u/chacoguy)\ **Post date:** [January 7, 2015, 1:42am UTC](https://boards.straightdope.com/t/could-t-rexes-jump/709178/1 "2015-01-07T01:42:29Z")
Well? Could they? ---
**Author:** ![jimbuff314](https://avatars.discourse-cdn.com/v4/letter/j/c57346/32.png) [@jimbuff314](https://boards.straightdope.com/u/jimbuff314)\ **Post date:** [January 7, 2015, 2:27am UTC](https://boards.straightdope.com/t/could-t-rexes-jump/709178/2 "2015-01-07T02:27:52Z")
Oh, someone please hurry and give a factual answer! I’ve got a good one but it must wait. ☹ ---
**Author:** ![The\_Joker\_and\_the\_Thief](https://avatars.discourse-cdn.com/v4/letter/t/e79b87/32.png) [@The\_Joker\_and\_the\_Thief](https://boards.straightdope.com/u/The_Joker_and_the_Thief)\ **Post date:** [January 7, 2015, 2:41am UTC](https://boards.straightdope.com/t/could-t-rexes-jump/709178/3 "2015-01-07T02:41:07Z")
Since [elephants can’t jump](http://www.straightdope.com/columns/read/1462/can-elephants-jump) and have a roughly comparable weight to [t-rexes](http://www.enchantedlearning.com/subjects/dinosaurs/facts/Trex/), I think its a good as guess as any that t-rexes couldn’t jump (though there’s probably no way to answer this conclusively). ---
**Author:** ![jimbuff314](https://avatars.discourse-cdn.com/v4/letter/j/c57346/32.png) [@jimbuff314](https://boards.straightdope.com/u/jimbuff314)\ **Post date:** [January 7, 2015, 2:48am UTC](https://boards.straightdope.com/t/could-t-rexes-jump/709178/4 "2015-01-07T02:48:15Z")
Yes, but they can’t dunk. 'Cause short arms, you know. ---
**Author:** ![running\_coach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/running_coach/32/15836_2.png) [@running\_coach](https://boards.straightdope.com/u/running_coach)\ **Post date:** [January 7, 2015, 2:53am UTC](https://boards.straightdope.com/t/could-t-rexes-jump/709178/5 "2015-01-07T02:53:29Z")
> [@jimbuff314](#): > > Yes, but they can’t dunk. 'Cause short arms, you know. But they sure as hell can eat up the shot clock. ---
**Author:** ![Ranchoth](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ranchoth/32/1066_2.png) [@Ranchoth](https://boards.straightdope.com/u/Ranchoth)\ **Post date:** [January 7, 2015, 3:03am UTC](https://boards.straightdope.com/t/could-t-rexes-jump/709178/6 "2015-01-07T03:03:49Z")
Depends on if you’re [in a Doc Savage story…](https://books.google.com/books?id=A6VQDYNkDUYC&pg=PA184&lpg=PA184&dq=doc+savage+tyranosaurus+kangaroo&source=bl&ots=3ueflEPocA&sig=CwmjjjpJZb6pujJphQ91_tu7RT4&hl=en&sa=X&ei=pKGsVMSCPYu2ogS6z4GoDw&ved=0CCIQ6AEwAA#v=onepage&q=doc%20savage%20tyranosaurus%20kangaroo&f=false) ---
**Author:** ![Renee](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/renee/32/287_2.png) [@Renee](https://boards.straightdope.com/u/Renee)\ **Post date:** [January 7, 2015, 3:13am UTC](https://boards.straightdope.com/t/could-t-rexes-jump/709178/7 "2015-01-07T03:13:31Z")
Chickens can jump quite well. Mine regularly hop onto things more than twice their height. Obviously, a chicken is not a T-rex, but there are similarities in their anatomy. I’m betting they could hop around a bit, despite their mass. ---
**Author:** ![AndrewL](https://avatars.discourse-cdn.com/v4/letter/a/3d9bf3/32.png) [@AndrewL](https://boards.straightdope.com/u/AndrewL)\ **Post date:** [January 7, 2015, 3:21am UTC](https://boards.straightdope.com/t/could-t-rexes-jump/709178/8 "2015-01-07T03:21:31Z")
But more importantly, could they dance? ---
**Author:** ![FluffyBob](https://avatars.discourse-cdn.com/v4/letter/f/ecb155/32.png) [@FluffyBob](https://boards.straightdope.com/u/FluffyBob)\ **Post date:** [January 7, 2015, 4:00am UTC](https://boards.straightdope.com/t/could-t-rexes-jump/709178/9 "2015-01-07T04:00:31Z")
I am not a qualified bio-mechanical science-talking-guy, but I am trying to imagine what a Tyrannosaurus jump would look like considering the modern assumption of a parallel to the ground stance. We are talking about a very big heavy animal with its weight spread out considerably fore and aft of its legs. I suspect the tail and head would tend to sag lower in response to an upward thrust at the hips. Usually a predator has to close suddenly with their prey at some point, if they couldn’t leap they must have at least been fast in some way. What a crazy animal. ---
**Author:** ![The\_Joker\_and\_the\_Thief](https://avatars.discourse-cdn.com/v4/letter/t/e79b87/32.png) [@The\_Joker\_and\_the\_Thief](https://boards.straightdope.com/u/The_Joker_and_the_Thief)\ **Post date:** [January 7, 2015, 4:04am UTC](https://boards.straightdope.com/t/could-t-rexes-jump/709178/10 "2015-01-07T04:04:12Z")
> [@FluffyBob](#): > > I am not a qualified bio-mechanical science-talking-guy, but I am trying to imagine what a Tyrannosaurus jump would look like considering the modern assumption of a parallel to the ground stance. We are talking about a very big heavy animal with its weight spread out considerably fore and aft of its legs. I suspect the tail and head would tend to sag lower in response to an upward thrust at the hips. > > Usually a predator has to close suddenly with their prey at some point, if they couldn’t leap they must have at least been fast in some way. What a crazy animal. Some guy made [an animation](http://vimeo.com/71398613) of it. If you can’t view the video, it looks like a feeble hobble where the front feet lift just a few inches off the ground. ---
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [January 7, 2015, 4:05am UTC](https://boards.straightdope.com/t/could-t-rexes-jump/709178/11 "2015-01-07T04:05:14Z")
Short answer, nobody knows. As one of the largest bipedal dinosaurs, T. Rex was presumably approaching the practical size limit, and was probably not as fast and nimble as smaller theropods. It’s still debated how fast T-Rex could run, or even if they were predators or mainly carrion eaters. One thing I’m fairly certain of was that despite what _100 Million BC_ depicted, a T-Rex couldn’t snatch a helicopter out of the air. ---
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [January 7, 2015, 4:17am UTC](https://boards.straightdope.com/t/could-t-rexes-jump/709178/12 "2015-01-07T04:17:22Z")
Rather than start a new thread, I’ll put a hopefully short hijack here: why did T-Rex and other predatory dinosaurs have such a deep keel-like pubis bone- especially since the other major two-legged dinosaur group, the hadrosaurs, did not. Usually a large bone is an important muscle attachment site, yet many depictions of T-Rex show it with a pubis bone with only a thin covering of skin. ---
**Author:** ![jimbuff314](https://avatars.discourse-cdn.com/v4/letter/j/c57346/32.png) [@jimbuff314](https://boards.straightdope.com/u/jimbuff314)\ **Post date:** [January 7, 2015, 5:09am UTC](https://boards.straightdope.com/t/could-t-rexes-jump/709178/13 "2015-01-07T05:09:34Z")
Having looked some for an answer as to whether they could jump (bloody, buggery scientists apparently refuse to speculate about silly things), I learned T Rex was among the most bird-like of theropods. Wiki entry says a grad student in 2010 did a study showing that the tail muscle mass may have been underestimated by as much as 45%. This “additional” mass probably helped move the center of mass aft, helping with balance. It also could have helped in turning - arch the tail and back and withdraw head and arms to spin somewhat in the manner of ice skaters withdrawing their arms to spin. Presumably, the pubis helped support this muscle mass. Possibly the depictions you mention may have been created before this discovery. Best I could do looking for answer in a rather ongoingly developing field of study. ---
**Author:** ![chacoguy](https://avatars.discourse-cdn.com/v4/letter/c/50afbb/32.png) [@chacoguy](https://boards.straightdope.com/u/chacoguy)\ **Post date:** [January 7, 2015, 7:31am UTC](https://boards.straightdope.com/t/could-t-rexes-jump/709178/14 "2015-01-07T07:31:26Z")
> [@jimbuff314](#): > > Oh, someone please hurry and give a factual answer! I’ve got a good one but it must wait. ☹ Thank You for the very first answer to a Factual Question. I’m sorry if I have offended anyone by asking obscure questions that are hard to “Google” . I thought that was the whole point of this place. Am I violating any board rules., or even culture? ---
**Author:** ![Critical1](https://avatars.discourse-cdn.com/v4/letter/c/3e96dc/32.png) [@Critical1](https://boards.straightdope.com/u/Critical1)\ **Post date:** [January 7, 2015, 8:03am UTC](https://boards.straightdope.com/t/could-t-rexes-jump/709178/15 "2015-01-07T08:03:00Z")
> [@chacoguy](#): > > Thank You for the very first answer to a Factual Question. I’m sorry if I have offended anyone by asking obscure questions that are hard to “Google” > . > I thought that was the whole point of this place. > > Am I violating any board rules., or even culture? You are totally fine, there is a rule in GQ where you cannot answer with silly/joke/snarky answers until after the question has been (or at least tried to have been) factually answered. He was just waiting for someone to come along with a good answer before he dropped the Cant Dunk Joke. ---
**Author:** ![jimbuff314](https://avatars.discourse-cdn.com/v4/letter/j/c57346/32.png) [@jimbuff314](https://boards.straightdope.com/u/jimbuff314)\ **Post date:** [January 7, 2015, 8:09am UTC](https://boards.straightdope.com/t/could-t-rexes-jump/709178/16 "2015-01-07T08:09:05Z")
Not offended, but I appreciate the apology anyway. And there’s tons of information on T Rexes but none I could find about their ability to leap into the air like 5 ton ballerinas. I say ballerinas because as it turns out there are 2 body morphologies for T Rexes. One is called _gracile_ and is lighter and somewhat thinner. The other is _robust_ and is presumed to be the females. These, obviously, are the much more heavily muscled variety and would presumably be the _pas-de-deuxers_. There _was_ some information about the G-forces they might have experienced if they fell wrapped into quite a lot of information about their running speed. It was pointed out that giraffes run at rather remarkable speeds facing much the same dangers and seem to manage okay. You’ve heard of giraffes, haven’t you? ---
**Author:** ![jimbuff314](https://avatars.discourse-cdn.com/v4/letter/j/c57346/32.png) [@jimbuff314](https://boards.straightdope.com/u/jimbuff314)\ **Post date:** [January 7, 2015, 9:08am UTC](https://boards.straightdope.com/t/could-t-rexes-jump/709178/17 "2015-01-07T09:08:05Z")
Bugger! I left a sentence off from the end of my post. It should have read “You’ve heard of giraffes, haven’t you? **Similar, except 2 legs instead of 4.** ” Sounded a bit rude and condescending without it, didn’t it? ---
**Author:** ![Ethilrist](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ethilrist/32/4604_2.png) [@Ethilrist](https://boards.straightdope.com/u/Ethilrist)\ **Post date:** [January 7, 2015, 2:00pm UTC](https://boards.straightdope.com/t/could-t-rexes-jump/709178/18 "2015-01-07T14:00:15Z")
> [@Critical1](#): > > You are totally fine, there is a rule in GQ where you cannot answer with silly/joke/snarky answers until after the question has been (or at least tried to have been) factually answered. He was just waiting for someone to come along with a good answer before he dropped the Cant Dunk Joke. And just wanted to post _something_ so it’d show up on his list of subscribed threads. ---
**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:** [January 7, 2015, 2:13pm UTC](https://boards.straightdope.com/t/could-t-rexes-jump/709178/19 "2015-01-07T14:13:58Z")
It’s hard to imagine a fast-moving biped that can’t jump. To move quickly with two legs, you have to have one lifting off the ground immediately after the other lands, meaning that you’re almost always supporting all of your weight on one leg. From there, it’s a very short step to occasionally having both off the ground at the same time (this happens with humans when we’re running, for instance). ---
**Author:** ![Really\_Not\_All\_That\_Bright](https://avatars.discourse-cdn.com/v4/letter/r/e8c25b/32.png) [@Really\_Not\_All\_That\_Bright](https://boards.straightdope.com/u/Really_Not_All_That_Bright)\ **Post date:** [January 7, 2015, 3:21pm UTC](https://boards.straightdope.com/t/could-t-rexes-jump/709178/20 "2015-01-07T15:21:06Z")
A little Googling suggests that adult ostriches can jump at least 4 feet, as experts recommend enclosures with at least six-foot fences. > [@Renee](#): > > Chickens can jump quite well. Mine regularly hop onto things more than twice their height. Obviously, a chicken is not a T-rex, but there are similarities in their anatomy. I’m betting they could hop around a bit, despite their mass. You’re probably onto something here. We now know that [theropod dinosaurs had pneumatized bones](http://www.ucmp.berkeley.edu/science/profiles/wedel_0609.php) just like modern birds, which implies that their bones weighed far less than those of a comparably sized mammal. So an elephant-sized theropod would have been much more agile than an elephant. Having said that, the mass of an animal scales exponentially with size, and we’re not really sure how much a T-rex would have weighed. [Next page](https://boards.straightdope.com/t/could-t-rexes-jump/709178.md?page=2)