You can´t outrun a T-Rex D:

Adam Khor

Here's an article that includes a speed chart for some theropods and modern day animals for comparison. As always this is an estimate of course.
It seems that even Usain Bolt wouldn´t survive for long in the Mesozoic...

http://io9.com/5961793/could-you-outrun-a-tyrannosaurus-rex?tag=paleontology



I'm finding it a little hard to believe that little Compsognathus ran THAT fast, or at least, that it ran that much FASTER than the other theropods.
I mean, similarly sized birds would be much slower, and Compsognathus doesn´t look particularly adapted as a speedster to me... and faster than an ostrich?? I doubt it...

What do you guys think?

Galvasean

Gotta love the "AKA T-rex" bit; as if people didn't know!!!?

Kess73

Just did the math on my marathon time from a few months back, and my average speed over that distance clocks in at 14 km/h.


My best sprint speed over 100m this year would only be around the 22km/h mark.



Looks like I am going to need a fair head start on a T Rex and then rely on it not being able to persue me for some 40km


Of course my strategy for a T Rex would be similar to that of if I was faced with sprinter style zombies, I would just make sure that I had other folk present, and then I only have to be able to outrun the slowest of them rather than being faster than the top speed of what is doing the chasing. :pac:


Allosaurus looks a nippy so and so going by those figures. Have seen a brown bear running close to flat out and was impressed with it's pace, so a 25 foot to 35 foot long theropod weighing anything up to two ton going at a similar pace would be hell on legs.


Going back to the T Rex for a moment though, an animal that size going at 28 km/h would be capable of catching the majority of the large herbivores of it's time. If anything the speed estimate just strengthens the idea that T-Rex was a hunter/scavenger and not the overgrown vulture that a certain Horner (spits) liked to suggest.

Rubecula

Sobering to think that in almost every time period, us, as humans, are just fresh meat. Until we get a nice heavy caliber gun that is

Kess73

Rubecula wrote: »

Sobering to think that in almost every time period, us, as humans, are just fresh meat. Until we get a nice heavy caliber gun that is

Even with the gun we are just a snack, unless we have plenty of time to spot the predator in advance and line up (and make) a killshot.

Adam Khor

Kess73 wrote: »

Even with the gun we are just a snack, unless we have plenty of time to spot the predator in advance and line up (and make) a killshot.

Agreed. Big game hunters used to say that the most dangerous animal is the one you don´t see coming.
I suspect many dinosaurs- including T-Rex- were more ambush hunters than sprinters.
I don´t doubt that they could run very fast if necessary but, why waste valuable energy chasing after hadrosaurs- I think the latest studies said that Edmontosaurus was probably faster than T-Rex after all- when you can hide near a waterhole and take one by surprise? (Now young T-Rex with those long skinny legs were probably another story altogether... )
Also, they didn´t do as much noise when walking as the JP films imply- they had soft tissue on their feet that allowed them to walk silently, like elephants today, so they could approach their prey without being heard either.
That's something dino documentaries always seem to forget...

Galvasean

I seem to recall hearing/reading that hadrosaurs were as fast as racehorses once they got into a sprint.

Adam Khor

[/QUOTE]

Galvasean wrote: »

I seem to recall hearing/reading that hadrosaurs were as fast as racehorses once they got into a sprint.

I bet a lot of their speed would have to do with the huge stride...

Galvasean

Apparently their tail was really muscular too; kind of worked like a rotor to propel them forward.

Adam Khor

Galvasean wrote: »

Apparently their tail was really muscular too; kind of worked like a rotor to propel them forward.

Oh yes, the tail... funny now that you mention it, how they say Carnotaurus was faster than other giant theropods partly because of its extremely developed caudofemoralis muscle, right?
Hadrosaurs do have very deep big tails, much bigger than any theropod's... maybe if they took this into account hadrosaur speed estimates would be even higher?

Kess73

Adam Khor wrote: »

Agreed. Big game hunters used to say that the most dangerous animal is the one you don´t see coming.
I suspect many dinosaurs- including T-Rex- were more ambush hunters than sprinters.
I don´t doubt that they could run very fast if necessary but, why waste valuable energy chasing after hadrosaurs- I think the latest studies said that Edmontosaurus was probably faster than T-Rex after all- when you can hide near a waterhole and take one by surprise? (Now young T-Rex with those long skinny legs were probably another story altogether... )
Also, they didn´t do as much noise when walking as the JP films imply- they had soft tissue on their feet that allowed them to walk silently, like elephants today, so they could approach their prey without being heard either.
That's something dino documentaries always seem to forget...

Totally agree that they were most likely ambush hunters. Most land based predators tend to use some degree of an ambush strategy in their hunting techniques,so I doubt if T Rex was any different.

Another thing that would come into play would be acceleration from standing rather than sprint speed. A hadrosaur may have had a higher top speed
than a T Rex, but that advantage would be greatly reduced if the T Rex had a greater acceleration over a short distance or was coming from cover (maybe even both).


Think your point about silent movement or rather quieter movement is a very valid one. If we look at many of today's large animals, for arguements sake lets cast a wide net and put the weight range at between 1000lbs and 12,000lbs, not many of them could fail to get within 30 feet of a human without being noticed given the right cover or conditions.

I reckon that if a human was put back in time to an area that containd a T Rex, there would be a very good chance of the T Rex getting to that 30 foot mark before the human even knew it was being stalked.

The thing that I think might have given a better indication of a T Rex being about is for the stalked hiuman to have a strong sense of smell. I am basing this theory on the likes of the Komodo dragon rather than larger modern day reptiles like crocodiles(although the same point holds true to a lesser degree for crocs despite being more aquatic).

The Komodo Dragons have a very distinct smell from their mouths, the acrid scent one might expect from a carnivore, that seems far stronger than what comes from a crocodile. Given the croc spend more time in water and has some avian help, it is not too much of a leap to assume that the croc might have as powerful a case of meaty bad breath if the water side of things was reduced to match the conditions the Komodos live in.

Now if we scale up to a T Rex and take into account that it was a carnivore that ate fresh meat and also scavenged meat that would be going off, then it must have really been in need of some industrial strength breath mints.

A komodo can be noticed by smell, assuming you are downwind with a good sense of smell, from a deceptively long distance, so my guess would be that the T Rex was an even stinkier beast. Now this was probaby of no use to most of what it ate back then as the prey species for the most part would not have had an olfactory system to take advantage, but for smaller predators of the era and our time travelling human it might have provided the precious extra yardage needed to avoid becoming a meal.

Adam Khor

Kess73 wrote: »

Totally agree that they were most likely ambush hunters. Most land based predators tend to use some degree of an ambush strategy in their hunting techniques,so I doubt if T Rex was any different.

Another thing that would come into play would be acceleration from standing rather than sprint speed. A hadrosaur may have had a higher top speed
than a T Rex, but that advantage would be greatly reduced if the T Rex had a greater acceleration over a short distance or was coming from cover (maybe even both).


Think your point about silent movement or rather quieter movement is a very valid one. If we look at many of today's large animals, for arguements sake lets cast a wide net and put the weight range at between 1000lbs and 12,000lbs, not many of them could fail to get within 30 feet of a human without being noticed given the right cover or conditions.

I reckon that if a human was put back in time to an area that containd a T Rex, there would be a very good chance of the T Rex getting to that 30 foot mark before the human even knew it was being stalked.

The thing that I think might have given a better indication of a T Rex being about is for the stalked hiuman to have a strong sense of smell. I am basing this theory on the likes of the Komodo dragon rather than larger modern day reptiles like crocodiles(although the same point holds true to a lesser degree for crocs despite being more aquatic).

The Komodo Dragons have a very distinct smell from their mouths, the acrid scent one might expect from a carnivore, that seems far stronger than what comes from a crocodile. Given the croc spend more time in water and has some avian help, it is not too much of a leap to assume that the croc might have as powerful a case of meaty bad breath if the water side of things was reduced to match the conditions the Komodos live in.

Now if we scale up to a T Rex and take into account that it was a carnivore that ate fresh meat and also scavenged meat that would be going off, then it must have really been in need of some industrial strength breath mints.

A komodo can be noticed by smell, assuming you are downwind with a good sense of smell, from a deceptively long distance, so my guess would be that the T Rex was an even stinkier beast. Now this was probaby of no use to most of what it ate back then as the prey species for the most part would not have had an olfactory system to take advantage, but for smaller predators of the era and our time travelling human it might have provided the precious extra yardage needed to avoid becoming a meal.

I was surprised the first time I worked with crocodiles in a zoo at how odorless they were... I expected at least some fishy breath but nothing.
I agree, tho, that theropods may have been different. Especially considering how incredibly well developed T-Rex's sense of smell was; it must have helped it not only to find carcasses or smell blood from great distances but also find potential mates or rivals...

Kess73

Adam Khor wrote: »

I was surprised the first time I worked with crocodiles in a zoo at how odorless they were... I expected at least some fishy breath but nothing.
I agree, tho, that theropods may have been different. Especially considering how incredibly well developed T-Rex's sense of smell was; it must have helped it not only to find carcasses or smell blood from great distances but also find potential mates or rivals...

That's why I used crocs as a contrast to Komodo dragons. A croc is not that stinky a creature unless you get very close to it's open mouth, and even then it is not the knock you down acrid smell (although the bite may be ) that one would get from a more terrestrial predator of decent size.


A komodo on the other hand can have rank predator breath that can be quite noticeable without having to be beside or overly near the animal.

So if we scale up to T Rex size, then we have a meat eater who potentially could have a very distinct and powerful case of bad breath. Given it's diet it certainly would not have been as prone to gas or noxious smells coming from it's rear end a la herbivores, but it could well have been prone to some distinct and very noticeable scents coming from it's mouth and also it's urine.


Given the olfactory systems that many of the large herbivores of the time must have had, the smell would not be a disadvantage to the T Rex, but I think it may have been useful for a rival T- Rex or smaller theropods as they would most likely have had the olfactory systems to pick up on it.

Capt'n Midnight

Rubecula wrote: »

Sobering to think that in almost every time period, us, as humans, are just fresh meat. Until we get a nice heavy caliber gun that is

we didn't need guns to wipe out most of the megafauna of Asia, the Americas , Oz and most islands

Adam Khor wrote: »

I bet a lot of their speed would have to do with the huge stride...

Wasn't there something about elephants not actually getting to a gallop

Galvasean wrote: »

Apparently their tail was really muscular too; kind of worked like a rotor to propel them forward.

and more importantly it could be used for rapid changes in direction, don't waste time zig-zagging when being chased by a raptor

Kess73 wrote: »

The Komodo Dragons have a very distinct smell from their mouths,

amazing that they are venomous as well as having rotting flesh in their mouths, one scratch and you'll probably get gangrene, with yer man following you at a slow steady pace for up to a week. Less chance of an ambushes vs. better chance of a meal from a successful one.

Galvasean

Kess73 wrote: »

it could well have been prone to some distinct and very noticeable scents coming from it's mouth and also it's urine.

Given the olfactory systems that many of the large herbivores of the time must have had, the smell would not be a disadvantage to the T Rex, but I think it may have been useful for a rival T- Rex or smaller theropods as they would most likely have had the olfactory systems to pick up on it.

JP3 was right :cool:

Adam Khor

Galvasean wrote: »

JP3 was right :cool:

Now imagine Spinosaurus' pee...

Kess73

Galvasean wrote: »

JP3 was right :cool:

I would subscribe to a lot of what JP3 claimed along those lines tbh.

Larger predator pees in an area to warn off rivals, and smaller predators avoid where they think someing bigger may be.

Also the smell of fresh pee would suggest that whatever made the pee is still close by.

The bit in the film where the kid says the T Rex pee attracts the spino makes sense also, because in the context of the film the Spino would be attracted by the scent of whatever it thought was encroughing on it's territory.

Galvasean

Adam Khor wrote: »

Now imagine Spinosaurus' pee...

Fishy?

But did dinos pee the way we do?



Probably not.

Capt'n Midnight

Galvasean wrote: »

Fishy?

But did dinos pee the way we do?

not really uric acid isn't as soluble and the wobbly bits are a little different on male mammals

Rubecula

Galvasean wrote: »

Fishy?

But did dinos pee the way we do?


Probably not.

Interesting question, I suspect dinos used to pee the way they birds do today, ie. they have a system where they excrete guano instead of peeing.

Kess73

Rubecula wrote: »

Interesting question, I suspect dinos used to pee the way they birds do today, ie. they have a system where they excrete guano instead of peeing.

I wonder did they.


Or did the system of forming urate crystals rather than forming urine come over time as climate/atmosphere changes came about.


Makes sense to think of dinos having a similar system to birds, but with a different level of oxygen, different humidities, and also the sheer size of some dinos (especially the larger herbivores and the larger carnivores) has me thinking that they either formed something similar to urine or had a system similar to what the larger birds (Ostrich etc) have today which to my knowledge is a dual excretion system ( fecal matter and urine are not discharged together).


What also has me wondering if they can create urine is the fact that the kidneys of an avian and the kidney of a reptile are very different now, and the avian kidney when the bird is suffering from dehydration will try to protect the system by concentrating the urine/ulric acid in a manner similar to how the kidney of a mammal will concentrate the urine (albeit to a much greater degree than an avian kidney can). But the kidney of a reptile cannot do this at all.


Another thing that stands out for me is that whilst most don't have one, some reptiles actually do have a urinary bladder, so my question would be is that a case of a section of modern reptiles starting to evolve or is it something that all reptiles may have had and the the minority that have them in modern times are just the tail end of what used to be?

Adam Khor

Kess73 wrote: »

I wonder did they.


Or did the system of forming urate crystals rather than forming urine come over time as climate/atmosphere changes came about.


Makes sense to think of dinos having a similar system to birds, but with a different level of oxygen, different humidities, and also the sheer size of some dinos (especially the larger herbivores and the larger carnivores) has me thinking that they either formed something similar to urine or had a system similar to what the larger birds (Ostrich etc) have today which to my knowledge is a dual excretion system ( fecal matter and urine are not discharged together).


What also has me wondering if they can create urine is the fact that the kidneys of an avian and the kidney of a reptile are very different now, and the avian kidney when the bird is suffering from dehydration will try to protect the system by concentrating the urine/ulric acid in a manner similar to how the kidney of a mammal will concentrate the urine (albeit to a much greater degree than an avian kidney can). But the kidney of a reptile cannot do this at all.


Another thing that stands out for me is that whilst most don't have one, some reptiles actually do have a urinary bladder, so my question would be is that a case of a section of modern reptiles starting to evolve or is it something that all reptiles may have had and the the minority that have them in modern times are just the tail end of what used to be?

All fascinating questions... I wonder if any organs linked to this were preserved in that Scipionyx fossil.