Interesting article with a short demonstration video

While our knowledge of dinosaurs and other extinct animals has dramatically increased during the last couple of decades, their gaits – the order and timing of how animals move their legs – have remained a blind spot.

We are particularly interested in the giant long-necked sauropod dinosaurs, which include the largest animals that walked the earth, including such famous species as Diplodocus, Brontosaurus and Brachiosaurus. How did these giants move? What role did efficiency and stability play during their locomotion?

….A 2016 study demonstrated that two animals of different sizes and using different gaits could produce identical track patterns. This means that to identify gait from the tracks we would need to know the trunk length of the animal (distance from hip to shoulder). Unfortunately it could not be accurately estimated from tracks so we were left with too many unknowns.

But one important aspect had not yet been taken into account – the variation along a set of tracks caused by small changes in speed. In our new study, we used this variation to present a new method to use tracks to work out which gait had been used.

Obviously the trunk length of an animal cannot change as it walks – so, we can therefore measure the trunk length from the tracks at many different points along it, while each time assuming a different gait. The gait which produces the most consistent trunk length along the tracks can be assumed to be the correct one.

It all made perfect mathematical sense. All we needed to do was make sure our new method worked when applied to the tracks of modern animals, including three dogs, two horses and an elephant. In each case, the method produced gratifyingly accurate estimates of the animals’ gaits.

So, for the first time we had developed a way to study gaits of the past. We applied the method to three fossilised tracks of giant sauropods from the Early Cretaceous period of Arkansas, in the US – the largest of which had footprint lengths of 85cm.

The results were really surprising….

Picky I know, but:

If they are talking about animals with reference to elephants, isn’t it a bit confusing to have the two words “trunk length” mean something other than the length of an elephant’s trunk?

The Rev Dodgson said:

Picky I know, but:

If they are talking about animals with reference to elephants, isn’t it a bit confusing to have the two words “trunk length” mean something other than the length of an elephant’s trunk?

trunk length of the animal (distance from hip to shoulder)

Well, the term was defined at its first use, so it shouldn’t be too confusing. For me that is far less confusing than someone using an undefined acronym or initialism.

Michael V said:

The Rev Dodgson said:

Picky I know, but:

If they are talking about animals with reference to elephants, isn’t it a bit confusing to have the two words “trunk length” mean something other than the length of an elephant’s trunk?

trunk length of the animal (distance from hip to shoulder)

Well, the term was defined at its first use, so it shouldn’t be too confusing. For me that is far less confusing than someone using an undefined acronym or initialism.

OK, I’ll pack my complaint in the trunk, and say no more about it.

The Rev Dodgson said:

Michael V said:

The Rev Dodgson said:

Picky I know, but:

If they are talking about animals with reference to elephants, isn’t it a bit confusing to have the two words “trunk length” mean something other than the length of an elephant’s trunk?

trunk length of the animal (distance from hip to shoulder)

Well, the term was defined at its first use, so it shouldn’t be too confusing. For me that is far less confusing than someone using an undefined acronym or initialism.

OK, I’ll pack my complaint in the trunk, and say no more about it.

Don’t you mean; in the boot?

roughbarked said:

The Rev Dodgson said:

Michael V said:

trunk length of the animal (distance from hip to shoulder)

Well, the term was defined at its first use, so it shouldn’t be too confusing. For me that is far less confusing than someone using an undefined acronym or initialism.

OK, I’ll pack my complaint in the trunk, and say no more about it.

Don’t you mean; in the boot?

No, no, a trunk like Nellie’s.

The Rev Dodgson said:

roughbarked said:

The Rev Dodgson said:

OK, I’ll pack my complaint in the trunk, and say no more about it.

Don’t you mean; in the boot?

No, no, a trunk like Nellie’s.

Isn’t that a tongue extension?

roughbarked said:

The Rev Dodgson said:

roughbarked said:

Don’t you mean; in the boot?

No, no, a trunk like Nellie’s.

Isn’t that a tongue extension?

?

You do know she had a trunk which she packed when she said goodbye to the circus?

The Rev Dodgson said:

roughbarked said:

The Rev Dodgson said:

No, no, a trunk like Nellie’s.

Isn’t that a tongue extension?

?

You do know she had a trunk which she packed when she said goodbye to the circus?

Never read the tail. ;)

The Rev Dodgson said:

roughbarked said:

The Rev Dodgson said:

No, no, a trunk like Nellie’s.

Isn’t that a tongue extension?

?

You do know she had a trunk which she packed when she said goodbye to the circus?

Never knew the whole song.

To Bombay a traveling circus came, they brought an
Intelligent elephant and Nellie was her name
One dark night she slipped her iron chain
And off she ran to Hindustan
And was never seen again
Oh

Nellie the elephant pack her trunk
And said goodbye to the circus
Off she went with a trumpety trump
Trump trump trump

Now Nellie the elephant packed her trunk
And trundled off to the jungle
Off she went with a trumpety trump
Trump trump trump

The head of the herd was calling far far away
They met one night in the silver light
On the road to Mandalay

Night by night she danced to the circus band
When Nellie was leading the big parade
She looked so proud and grand
No more tricks for Nellie to perform
They taught her how to take a bow
And she took the crowd by storm
Oh

I can’t believe that elephants run like that. The pace gait is very slow and energy consuming.
I’m sure that a running elephant would never use a pace gait. And a walking elephant moves one foot at a time so is not a pace gait either.

Oh, OK. Looking at running elephants https://www.youtube.com/watch?v=H_D4qqciraI they use a gait that is neither a pace nor a trot, but half way in between, one foot at a time at equal time intervals. This serves to distribute the weight more evenly on each foot, at the expense of more energy expenditure to move.

That sauropods and hippo use a trot gait is not at all surprising. It’s the least energy (apart from kangaroo but that’s a different story). Even humans quick walk is a diagonal couplets gait, with right arm swinging forward as left leg swings forward.

I tried unsuccessfully to make a running robot once, using a diagonal coupled gait that could be varied from trot to bound.