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Parallel Convergence: Tendon locking and Tail loss

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DD'eDeN aka note/nickname/alas_my_loves

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Oct 21, 2021, 9:41:09 PM10/21/21
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Independent evolution of arboreal tendon locking limbs and inevitably resulting loss of perch-counterbalancing long boney tail in primitive vs derived pterosaurs, avian and anthropoids. (DDeden)

https://www.shutterstock.com/video/search/sleeping-monkey-tree

monkeys (and hominoids on flat ground) sleep compressionally with loose digits, but hominoids asleep in branches clutch branches with hands and feet tensionally in tendon lock to prevent falls.

https://images.app.goo.gl/V6UHmNa8ZPBG1Ugi6

Sitting upright on ischial callosities with loose digits isn't perching in the sense of sleeping tensionally on branches:

https://images.app.goo.gl/8AKWJMfTej6HSh1CA asleep

https://images.app.goo.gl/F3XYHemQMDUcyWSb8 asleep gripping

https://images.app.goo.gl/iem65b1yvwZsXKMw9 asleep gripping

Those (below) asleep on flat grassy ground (zoo) have open or loose hands and feet, like humans do. That seems significant to me.

Note wrt earlier claims: I shouldn't have said 'upright perching', but simply 'grasped (tensional) perching' as seen in modern arboreal avians, late pterosaurs and hominoids as opposed to primitive 'balanced (compressional)  perching' where the long boney tail behind offsets the boney neck & teethy skull in front as seen in proto-avian, early pterosaurs and many monkeys.

https://images.app.goo.gl/rRwqvzjrjPnytQK27

https://images.app.goo.gl/S9RTd1QRz3T2Tsu56

https://images.app.goo.gl/JikKJ96v2voP4X4u

Gripping fruit with feet while hanging from branch above is like an eagle gliding down to pluck a mouse between its talons, or a pterodactyle landing on a branch.

https://www.pnas.org/content/118/44/e2107631118 pterosaurs developed tendon lock and lost long boney tail and improved aerodynamic form.

"Pterosaurs were the first vertebrate group to achieve powered flight and were successful in the aerial realm for over 160 million years (1). Pterosaurs operated uniquely with a membrane wing held in tension by a hyperelongated fourth finger "

This finger had tendon lock for gliding thermals & breezes but unlocked for flapping flight. Where did it perch for insect prey? Branches, cliffs? Tendon lock to stay upright against winds and to rest. On ground tendons unlocked allowing walking on flat ground.

The oldest pterosaurs, avians and anthropoids had no tendon locking, later specialized descendants independently/convergently evolved tendon locking AND lost long boney tails.

"We observed that the fairing in BSP 1937 I 18 is formed of soft tissue body contours. Such a fairing muscle supports the aerodynamic requirements of the mobile insectivore ecology proposed for this pterodactyloid pterosaur".

Pterodactyls were LATER, so had tendon lock and tiny tails. Same with LATER birds and apes.

See this article on avian talon locking, note the illustration and the update: 

https://amp-theatlantic-com.cdn.ampproject.org/v/s/amp.theatlantic.com/amp/article/281969/?amp_js_v=a6&amp_gsa=1&usqp=mq331AQKKAFQArABIIACAw%3D%3D#aoh=16337036955606&referrer=https%3A%2F%2Fwww.google.com&amp_tf=From%20%251%24s&ampshare=https%3A%2F%2Fwww.theatlantic.com%2Ftechnology%2Farchive%2F2013%2F12%2Fwhy-birds-can-sleep-on-branches-and-not-fall-off%2F281969%2F

And heres the 2010 article on European starlings:

https://onlinelibrary.wiley.com/doi/abs/10.1002/jez.1714

I'd note that possibly European starlings and many non-arboreal waterfowl (penguins?) never had raptorial-arboreal ancestors and may have had slightly different perching methods, so the tendon locking might differ. (Similarly so in some pterosaurs, anthropoids and hominoids.)


Should I submit a paper on this?

DD

Paul Crowley

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Oct 22, 2021, 5:29:03 PM10/22/21
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On Friday, October 22, 2021 at 2:41:09 AM UTC+1, DD'eDeN aka note/nickname/alas_my_loves wrote:

> Independent evolution of arboreal tendon locking limbs and inevitably resulting loss of perch-
> counterbalancing long boney tail in primitive vs derived pterosaurs, avian and anthropoids. (DDeden)

> [..]

> I'd note that possibly European starlings and many non-arboreal waterfowl (penguins?) never had
> raptorial-arboreal ancestors and may have had slightly different perching methods, so the tendon locking
> might differ. (Similarly so in some pterosaurs, anthropoids and hominoids.)
>
> Should I submit a paper on this?

It would be nice to know what "this" is about.
You've been 'communicating' with Verhaegen too
much. Please write SENTENCES in a language you
know (preferably English). A list of apparently
random topics or references may make sense to
you. It doesn't to anyone else.

littor...@gmail.com

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Oct 22, 2021, 6:18:57 PM10/22/21
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Op vrijdag 22 oktober 2021 om 03:41:09 UTC+2 schreef DD'eDeN aka note/nickname/alas_my_loves:

Pterosaurs evolved a muscular wing–body junction providing multifaceted flight performance benefits:
Advanced aerodynamic smoothing, sophisticated wing root control, and wing force generation
Michael Pittman cs 2021 PNAS 118 (44) e2107631118 doi org/10.1073/pnas.2107631118

Experimental Analysis of Perching in the European Starling (Sturnus vulgaris: Passeriformes; Passeres),
and the Automatic Perching Mechanism of Birds
PM Galton & JD Shepherd 2012 doi org/10.1002/jez.1714

My little boy, I seriously tried to follow your thoughts, but it's impossible:
do you really have flying ancestors, my boy?

The aquarboreal idea is simple:
Miocene hominoids frequently waded upright for fruits/nuts in swamp forests:
of course, they lost the tail, climbed arms overhead, got broad bodies (Latisternalia), centrally-placed spines etc.
Google our TREE paper "aquarboreal ancestors".

_______

DD'eDeN aka note/nickname/alas_my_loves

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Oct 22, 2021, 7:52:21 PM10/22/21
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On Friday, October 22, 2021 at 5:29:03 PM UTC-4, Paul Crowley wrote:
> On Friday, October 22, 2021 at 2:41:09 AM UTC+1, DD'eDeN aka note/nickname/alas_my_loves wrote:
>
> > Independent evolution of arboreal tendon locking limbs and inevitably resulting loss of perch-
> > counterbalancing long boney tail in primitive vs derived pterosaurs, avian and anthropoids. (DDeden)
> > [..]
> > I'd note that possibly European starlings and many non-arboreal waterfowl (penguins?) never had
> > raptorial-arboreal ancestors and may have had slightly different perching methods, so the tendon locking
> > might differ. (Similarly so in some pterosaurs, anthropoids and hominoids.)
> >
> > Should I submit a paper on this?
> It would be nice to know what "this" is about.

This: Independent evolution of arboreal tendon locking limbs and inevitably resulting loss of perch-counterbalancing long boney tail in primitive vs derived 1) pterosaurs, 2) avians and 3) anthropoids. (DDeden)

> You've been 'communicating' with Verhaegen too
> much. Please write SENTENCES in a language you
> know (preferably English). A list of apparently
> random topics or references may make sense to
> you. It doesn't to anyone else.

Thanks for the feedback.

I am considering writing an online article, with numerous links to support my claim.

DD'eDeN aka note/nickname/alas_my_loves

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Oct 22, 2021, 8:02:48 PM10/22/21
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On Friday, October 22, 2021 at 6:18:57 PM UTC-4, littor...@gmail.com wrote:
> Op vrijdag 22 oktober 2021 om 03:41:09 UTC+2 schreef DD'eDeN aka note/nickname/alas_my_loves:
>
> Pterosaurs evolved a muscular wing–body junction providing multifaceted flight performance benefits:
> Advanced aerodynamic smoothing, sophisticated wing root control, and wing force generation
> Michael Pittman cs 2021 PNAS 118 (44) e2107631118 doi org/10.1073/pnas.2107631118
>
> Experimental Analysis of Perching in the European Starling (Sturnus vulgaris: Passeriformes; Passeres),
> and the Automatic Perching Mechanism of Birds
> PM Galton & JD Shepherd 2012 doi org/10.1002/jez.1714
>
> My little boy, I seriously tried to follow your thoughts, but it's impossible:
> do you really have flying ancestors, my boy?

Flight employs united forelimbs extended in tension during gliding,
contracted in compression during flapping, unlike alternative limb brachiation. However all 3 perch(ed) in tension.
>
> The aquarboreal idea is simple:
> Miocene hominoids frequently waded

Irrelevant to topic. Wading played no part in the loss of long boney tail in pterosaurs, avians or anthropoids.

littor...@gmail.com

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Oct 23, 2021, 5:18:23 PM10/23/21
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Op zaterdag 23 oktober 2021 om 02:02:48 UTC+2 schreef DD'eDeN aka note/nickname/alas_my_loves:


> > Pterosaurs evolved a muscular wing–body junction providing multifaceted flight performance benefits:
> > Advanced aerodynamic smoothing, sophisticated wing root control, and wing force generation
> > Michael Pittman cs 2021 PNAS 118 (44) e2107631118 doi org/10.1073/pnas.2107631118

> > Experimental Analysis of Perching in the European Starling (Sturnus vulgaris: Passeriformes; Passeres),
> > and the Automatic Perching Mechanism of Birds
> > PM Galton & JD Shepherd 2012 doi org/10.1002/jez.1714

> > My little boy, I seriously tried to follow your thoughts, but it's impossible:
> > do you really have flying ancestors, my boy?


> Flight employs united forelimbs extended in tension during gliding,
> contracted in compression during flapping, unlike alternative limb brachiation. However all 3 perch(ed) in tension.

???
If so, what has this to do with *hominoid* evolution??
Do you really believe your ancestors flied, DD??
We have enough imbeciles here who believe their ancestors ran after kudus, but this is no less ridiculous.


> > The aquarboreal idea is simple:
> > Miocene hominoids frequently waded

> Irrelevant to topic. Wading played no part in the loss of long boney tail in pterosaurs, avians or anthropoids.
> upright for fruits/nuts in swamp forests:

Most likely, wading bipedally/vertically/upright (for fruits/nuts?) *caused* hominoid tail loss:
-it was of no use for equilibrium, support etc.: slow & vertical locomotion in forest swamps
(mangroves? I still don't know for sure),
-it caused heat loss,
-it was prone to infections, biting fishes, injuries etc.
Nasalis concolor is only infrequently wading, but has already a shortened tail.

Of course, they lost the tail, climbed arms overhead, got broad bodies (Latisternalia), centrally-placed spines etc.

DD'eDeN aka note/nickname/alas_my_loves

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Oct 23, 2021, 7:39:48 PM10/23/21
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On Saturday, October 23, 2021 at 5:18:23 PM UTC-4, littor...@gmail.com wrote:
> Op zaterdag 23 oktober 2021 om 02:02:48 UTC+2 schreef DD'eDeN aka note/nickname/alas_my_loves:
> > > Pterosaurs evolved a muscular wing–body junction providing multifaceted flight performance benefits:
> > > Advanced aerodynamic smoothing, sophisticated wing root control, and wing force generation
> > > Michael Pittman cs 2021 PNAS 118 (44) e2107631118 doi org/10.1073/pnas.2107631118
>
> > > Experimental Analysis of Perching in the European Starling (Sturnus vulgaris: Passeriformes; Passeres),
> > > and the Automatic Perching Mechanism of Birds
> > > PM Galton & JD Shepherd 2012 doi org/10.1002/jez.1714
>
> > > My little boy, I seriously tried to follow your thoughts, but it's impossible:
> > > do you really have flying ancestors, my boy?
> > Flight employs united forelimbs extended in tension during gliding,
> > contracted in compression during flapping, unlike alternative limb brachiation. However all 3 perch(ed) in tension.
> ???
> If so, what has this to do with *hominoid* evolution??
> Do you really believe your ancestors flied, DD??
Hominoids share slow brachiation, upright bipedalism, tensional perching.

> We have enough imbeciles here who believe their ancestors ran after kudus, but this is no less ridiculous.
> > > The aquarboreal idea is simple:
> > > Miocene hominoids frequently waded
>
> > Irrelevant to topic. Wading played no part in the loss of long boney tail in pterosaurs, avians or anthropoids.
> > upright for fruits/nuts in swamp forests:
> Most likely, wading

Irrelevant here.

bipedally/vertically/upright (for fruits/nuts?) *caused* hominoid tail loss:
> -it was of no use for equilibrium, support etc.: slow & vertical locomotion in forest swamps
> (mangroves? I still don't know for sure),
> -it caused heat loss,
> -it was prone to infections, biting fishes, injuries etc.
> Nasalis concolor is only infrequently wading, but has already a shortened tail.

Please provide cites or photos of concolor wading.

Nasalas concolor (simkobu) langur monkey

Social structure among families of two to five animals (mean = 3.5) was determined for groups living in the central (highland) primary rain forest.

Simkobu evade human predation by minimizing conspicuous movements and vocalizations, by concealment in the canopy, or by rapid terrestrial flight when detected.

The habitat of S. concolor includes hillsides in primary forests.

This species is entirely arboreal and only comes down from the trees when it is disturbed.

No wading cited. I don't know if they use tendon locking. Sloths do and have short tails.

littor...@gmail.com

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Oct 24, 2021, 10:03:22 AM10/24/21
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Op zondag 24 oktober 2021 om 01:39:48 UTC+2 schreef DD'eDeN aka note/nickname/alas_my_loves:


> > > > Pterosaurs evolved a muscular wing–body junction providing multifaceted flight performance benefits:
> > > > Advanced aerodynamic smoothing, sophisticated wing root control, and wing force generation
> > > > Michael Pittman cs 2021 PNAS 118 (44) e2107631118 doi org/10.1073/pnas.2107631118
> > > > Experimental Analysis of Perching in the European Starling (Sturnus vulgaris: Passeriformes; Passeres),
> > > > and the Automatic Perching Mechanism of Birds
> > > > PM Galton & JD Shepherd 2012 doi org/10.1002/jez.1714

> > > > My little boy, I seriously tried to follow your thoughts, but it's impossible:
> > > > do you really have flying ancestors, my boy?

> > > Flight employs united forelimbs extended in tension during gliding,
> > > contracted in compression during flapping, unlike alternative limb brachiation. However all 3 perch(ed) in tension.

> > ???
> > If so, what has this to do with *hominoid* evolution??
> > Do you really believe your ancestors flied, DD??

> Hominoids share slow brachiation, upright bipedalism, tensional perching.

Of course slow vertical climbing & BPism: wading = aquarboreal.
That's why they lost the tail, got very broad thorax (Latisternalia) & pelvis (iliac flaring): later l movements of arms (also overhead) & legs.

Tensional perching apes?? No evidence, my boy.

> > We have enough imbeciles here who believe their ancestors ran after kudus, but this is no less ridiculous.

> > > > The aquarboreal idea is simple:
> > > > Miocene hominoids frequently waded

> > > Irrelevant to topic.

Essential to hominoid evolution.

> > > Wading played no part in the loss of long boney tail in pterosaurs, avians

I have no idea, but if you want to believe that, go ahead.
Apes don't fly, my little boy.

> > > or anthropoids.

If you mean hominoids: aquarboreal - has 0 to do with perching.

> > > upright for fruits/nuts in swamp forests:

> > Most likely, wading

> Irrelevant here.

Wading is essential to hominoid evolution.

> > bipedally/vertically/upright (for fruits/nuts?) *caused* hominoid tail loss:
> > -it was of no use for equilibrium, support etc.: slow & vertical locomotion in forest swamps
> > (mangroves? I still don't know for sure),
> > -it caused heat loss,
> > -it was prone to infections, biting fishes, injuries etc.
> > Nasalis concolor is only infrequently wading, but has already a shortened tail.

> Please provide cites or photos of concolor wading.

https://www.newscientist.com/article/2074675-meet-the-aquatic-monkey-with-a-love-of-diving-and-swimming/
"Meet the aquatic monkey with a love of diving and swimming"
Nasalis is only incipiently wading, and already has a shortened tail.
See also E.Morgan 1982 "The Aquatic Ape" Souvenir photo p.96.

> Nasalis concolor (simkobu) langur monkey

simAkobu

> Social structure among families of two to five animals (mean = 3.5) was determined for groups living in the central (highland) primary rain forest.
> Simkobu evade human predation by minimizing conspicuous movements and vocalizations, by concealment in the canopy, or by rapid terrestrial flight when detected.
> The habitat of S. concolor includes hillsides in primary forests.
> This species is entirely arboreal and only comes down from the trees when it is disturbed.

Apparently not.

> No wading cited. I don't know if they use tendon locking. Sloths do and have short tails.

You're obsessed by "tendon locking"; grow up, my boy.

Oligo?Miocene wading-climbing hominoids lost the tail, climbed arms overhead, got broad bodies (Latisternalia), centrally-placed spines etc.
:-D

DD'eDeN aka note/nickname/alas_my_loves

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Oct 24, 2021, 10:18:38 AM10/24/21
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littor...@gmail.com

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Oct 24, 2021, 10:52:32 AM10/24/21
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Op zondag 24 oktober 2021 om 16:18:38 UTC+2 schreef DD'eDeN aka note/nickname/alas_my_loves:

> > > > > > Pterosaurs evolved a muscular wing–body junction providing multifaceted flight performance benefits:
> > > > > > Advanced aerodynamic smoothing, sophisticated wing root control, and wing force generation
> > > > > > Michael Pittman cs 2021 PNAS 118 (44) e2107631118 doi org/10.1073/pnas.2107631118
> > > > > > Experimental Analysis of Perching in the European Starling (Sturnus vulgaris: Passeriformes; Passeres),
> > > > > > and the Automatic Perching Mechanism of Birds
> > > > > > PM Galton & JD Shepherd 2012 doi org/10.1002/jez.1714

> > > > > > My little boy, I seriously tried to follow your thoughts, but it's impossible:
> > > > > > do you really have flying ancestors, my boy?

> > > > > Flight employs united forelimbs extended in tension during gliding,
> > > > > contracted in compression during flapping, unlike alternative limb brachiation. However all 3 perch(ed) in tension.

> > > > ??? If so, what has this to do with *hominoid* evolution??
> > > > Do you really believe your ancestors flied, DD??

> > > Hominoids share slow brachiation, upright bipedalism, tensional perching.

> > Of course slow vertical climbing & BPism: wading = aquarboreal.
> > That's why they lost the tail, got very broad thorax (Latisternalia) & pelvis (iliac flaring): later l movements of arms (also overhead) & legs.

Still no answer.

> > Tensional perching apes?? No evidence, my boy.

Id.

> > > > We have enough imbeciles here who believe their ancestors ran after kudus, but this is no less ridiculous.

> > > > > > The aquarboreal idea is simple:
> > > > > > Miocene hominoids frequently waded

> > > > > Irrelevant to topic.

> > Essential to hominoid evolution.

> > > > > Wading played no part in the loss of long boney tail in pterosaurs, avians

> > I have no idea, but if you want to believe that, go ahead.
> > Apes don't fly, my little boy.

> > > > > or anthropoids.

> > If you mean hominoids: aquarboreal - has 0 to do with perching.

No answer.

> > > > > upright for fruits/nuts in swamp forests:

> > > > Most likely, wading

> > > Irrelevant here.

> > Wading is essential to hominoid evolution.

No answer.

> > > > bipedally/vertically/upright (for fruits/nuts?) *caused* hominoid tail loss:
> > > > -it was of no use for equilibrium, support etc.: slow & vertical locomotion in forest swamps
> > > > (mangroves? I still don't know for sure),
> > > > -it caused heat loss,
> > > > -it was prone to infections, biting fishes, injuries etc.
> > > > Nasalis concolor is only infrequently wading, but has already a shortened tail.

> > > Please provide cites or photos of concolor wading.

> > https://www.newscientist.com/article/2074675-meet-the-aquatic-monkey-with-a-love-of-diving-and-swimming/
> > "Meet the aquatic monkey with a love of diving and swimming"
> > Nasalis is only incipiently wading, and already has a shortened tail.
> > See also E.Morgan 1982 "The Aquatic Ape" Souvenir photo p.96.

Not seen these??

> > > Nasalis concolor (simkobu) langur monkey

> > simAkobu

> > > Social structure among families of two to five animals (mean = 3.5) was determined for groups living in the central (highland) primary rain forest.
> > > Simkobu evade human predation by minimizing conspicuous movements and vocalizations, by concealment in the canopy, or by rapid terrestrial flight when detected.
> > > The habitat of S. concolor includes hillsides in primary forests.
> > > This species is entirely arboreal and only comes down from the trees when it is disturbed.

> > Apparently not.

See different books of Elaine Morgan.

> > > No wading cited. I don't know if they use tendon locking. Sloths do and have short tails.

Yes, short, but not absent as in apes.
Very slow climbing?? But apes are fast or very fast.

> > You're obsessed by "tendon locking"; grow up, my boy.

No answer: sorry, DD, but I really don't see the relevance of tendon locking here.

> > Oligo?Miocene wading-climbing hominoids lost the tail, climbed arms overhead, got broad bodies (Latisternalia), centrally-placed spines etc.
> > Google our TREE paper "aquarboreal ancestors".

> Please provide cites or photos of concolor wading.
> Please provide cites or photos of concolor wading.
> Please provide cites or photos of concolor wading.

:-) You're right to repeat this, DD.
Cites or illustrations isn't difficult:
haven't you read Elaine's books??
e.g. see above, or "The aquatic ape hypothesis" p.64-66, 161-2.

Nasalis does wade, but infrequently apparently,
I have no idea: more so during warmer periods?? Ice Ages...
But its tail hasn't disappeared, only reduced - very unexpected for fast arboreal primates.
Hominoid tail loss can't be explained by aquarborealism, but easily by aquarborealism.
Miocene hominoids were strongly aquarboreal,
google e.g. "Aquarboreal Ancestors?".

I had proposed this bipedally-wading-climbing locomotion even before the wading gorillas-bonobos-orangs were discovered!
When the photos of wading gorilla appeared (c 1995 IIRC), I thought (naively - as usual): now they will soon accept AAT,
but nothing happened... they're still running after their kudus... the incredible idiots.

DD'eDeN aka note/nickname/alas_my_loves

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Oct 24, 2021, 12:55:42 PM10/24/21
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> > Please provide cites or photos of concolor wading.
> > Please provide cites or photos of concolor wading.
> > Please provide cites or photos of concolor wading
> > Please provide cites or photos of concolor wading.
> > Please provide cites or photos of concolor wading.
> > Please provide cites or photos of concolor wading
> > Please provide cites or photos of concolor wading.
> > Please provide cites or photos of concolor wading.
> > Please provide cites or photos of concolor wading
> > Please provide cites or photos of concolor wading.
> > Please provide cites or photos of concolor wading.
> > Please provide cites or photos of concolor wading
> > Please provide cites or photos of concolor wading.
> > Please provide cites or photos of concolor wading.
> > Please provide cites or photos of concolor wading> > Please provide cites or photos of concolor wading.

littor...@gmail.com

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Oct 24, 2021, 1:22:10 PM10/24/21
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Op zondag 24 oktober 2021 om 18:55:42 UTC+2 schreef DD'eDeN aka note/nickname/alas_my_loves:


Given, my little little boy.
Grow up, ridiculous child
See *at least* Morgan's books.

DD'eDeN aka note/nickname/alas_my_loves

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Oct 26, 2021, 11:04:28 AM10/26/21
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On Sunday, October 24, 2021 at 12:55:42 PM UTC-4, DD'eDeN aka note/nickname/alas_my_loves wrote:.
> > > Please provide cites or photos of concolor wading.
.

DD'eDeN aka note/nickname/alas_my_loves

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Oct 26, 2021, 11:16:42 AM10/26/21
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No-one made any recommendations on whether I ought to author a paper on the shared traits of tendon locking and derived tail loss.

I may tie it to the human condition of nocturnal leg (calf) cramps aka "charley horse", where the tendon lock engages accidentally producing pain, relieved by standing orthograde.

DD'eDeN aka note/nickname/alas_my_loves

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Oct 26, 2021, 7:04:08 PM10/26/21
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On Thursday, October 21, 2021 at 9:41:09 PM UTC-4, DD'eDeN aka note/nickname/alas_my_loves wrote:
https://www.earthtouchnews.com/discoveries/fossils/hundreds-of-fossilised-eggs-reveal-the-nesting-habits-of-ancient-flying-reptiles/

While avians & hominoids evolved arboreal bowl nesting, pterosaurs at early stage laid eggs on ground near flowing water 100ma. It is not known if later pterodactyls laid eggs in arboreal bowl nests.

DD'eDeN aka note/nickname/alas_my_loves

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Oct 27, 2021, 11:07:37 PM10/27/21
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> While avians & hominoids evolved arboreal bowl nesting, pterosaurs at early stage laid eggs on ground near flowing water 100ma. It is not known if later pterodactylus laid eggs in arboreal bowl nests, but they had good climbing traits.

https://www.thoughtco.com/pterodactyl-dinosaur-pictures-4123094
https://en.m.wikipedia.org/wiki/Pterosaur

DD'eDeN aka note/nickname/alas_my_loves

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Oct 28, 2021, 4:10:24 AM10/28/21
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The two mammals (of the forest) with lowest metabolisms are the sloth (1) and then the orangutan (2), both of whom spend most of the day hanging suspended from treebranches. Without the ability to lock their tendons, they would have to expend energy consciously grasping branches in tension, quickly burning calories. Tendon locking is an energy-saving feature.

DD'eDeN aka note/nickname/alas_my_loves

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Oct 29, 2021, 9:54:41 AM10/29/21
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>> Open access:
> >> > > >> https://www.pnas.org/content/118/44/e2107631118
> >> > > >
> >> > > >Excellent, thanks Pandora. I'm too rushed to read all, but a question. Did it have a long boney tail
> >> > > >(thus compressional perching as seen in early pterosaurs, avians & anthropoids), or, did it have
> >> > > >tendon-locking toes for upright perching & plucking and tail-lessening as in later pterosaurs, avians
> >> > > >and hominoids? I suspect the latter, and expect the soft-tissue fairing indicated very advanced
> >> > > >aerodynamic specialization not seen in early species. DD
> >> > > It's a pterodactyloid, therefore short-tailed.
> >> > Yes, a nimble flying insectivore, comparable to songbirds, swifts, small bats. I wonder if it had derived specialized ears (acoustic, aerodynamic balance) vs more primitive spp.
> >> Did later pterosaurs (eg. reduced teeth tailless climbing Pterodactylus, toothless tailless pterodon) lay eggs on the ground like early pterosaurs penguin-like or in arboreal bowl nests? How can that be determined?
> >Some sources claim pterosaurs were quadrupedal, some bipedal.

Pandora at SBP:
> See:
> https://www.sciencedirect.com/science/article/abs/pii/S0016699520300024
>
> "After two centuries of debate, ichnological arguments have led
> today to an almost global consensus on the terrestrial locomotion
> of pterodactyloid pterosaurs. When grounded, they were quadrupedal
> animals, with plantigrade tetradactyl pes, digitigrade tridactyl
> manus, erect parasagittal hindlimbs and more or less sprawled
> forelimbs due to the large folded wing digit."

Thanks. I don't know if they used the same posture/locomotion on tree branches or cliffs, nor if they sometimes went bipedal.
Bats also fly and perch, some hang upside-down by tendon locking their feet, others apparently lock the tendons of all four limbs to cliff faces (head up) or cave ceilings (belly up). Afaik no bats catch prey with their feet raptor-style.
Sloths use tendon lock, perhaps some opposums too, during rest afaict

DD'eDeN aka note/nickname/alas_my_loves

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Oct 31, 2021, 9:19:31 PM10/31/21
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> Sloths use tendon lock, perhaps some opposums (arboreal wombats?)too, during rest afaict.

Tail loss indicates arboreal perching while napping/sleeping, limb tendons locked to prevent falls, as seen in hylobatids. Chimps & gorillas then evolved knucklewalking which require curled fists in tendon lock to provide stability at speed, along with bowl nests for sleep, so lessening the advantage of tendon lock.

DD'eDeN aka note/nickname/alas_my_loves

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Oct 31, 2021, 10:04:42 PM10/31/21
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Ape kids must have tendon locking hands and feet to stay anchored to their mother while she moves actively foraging.
Human kids have no fur coat or loose skin to hold onto, aside from piggyback riding and grasping long scalp hair.
Tendon lock may have been reduced in human hands to better manipulate tools in all directions.
Carpal tunnel syndrome may be an avatism of ancestral tendon locking, being significant in repetitive finger motions such as using the now-obsolete manual typewriters, where the arms are largely static but the wrists and fingers torque and press constantly.

Are charley horse calf cramps and carpal tunnel of the manus 'scars of evolution' of hominoid arboreal tendon locking?
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