Today's News on Pterosaur Origins

[Peter Nyikos]

A research article in the prestigious journal *Nature* gives new evidence for
the hypothesis that the "early Late Triassic" lagerpeptid *Scleromochlus*
is close to the direct ancestry of pterosaurs.

Abstract
Mesozoic terrestrial ecosystems from their sudden appearance in the Late Triassic until their demise at the end of the Cretaceous [1],[2],[3],[4],[5],[6]. However, the origin and early evolution of pterosaurs are poorly understood owing to a substantial stratigraphic and morphological gap between these reptiles and their closest relatives [6], Lagerpetidae [7]. Scleromochlus taylori, a tiny reptile from the early Late Triassic of Scotland discovered over a century ago, was hypothesized to be a key taxon closely related to pterosaurs [8], but its poor preservation has limited previous studies and resulted in controversy over its phylogenetic position, with some even doubting its identification as an archosaur [9]. Here we use microcomputed tomographic scans to provide the first accurate whole-skeletal reconstruction and a revised diagnosis of Scleromochlus, revealing new anatomical details that conclusively identify it as a close pterosaur relative [1] within Pterosauromorpha (the lagerpetid + pterosaur clade). Scleromochlus is anatomically more similar to lagerpetids than to pterosaurs and retains numerous features that were probably present in very early diverging members of Avemetatarsalia (bird-line archosaurs). These results support the hypothesis that the first flying reptiles evolved from tiny, probably facultatively bipedal, cursorial ancestors [1].

D. Foffa + 10 co-authors, "Scleromochlus and the early evolution of Pterosauromorpha, 05 October 2022,
https://www.nature.com/articles/s41586-022-05284-x

Expertly illustrated, with a detailed reconstruction and:
Fig. 3: Time-calibrated strict consensus tree focused on Pterosauromorpha and different positions of S. taylori based on interpretations of the phylogenetic scores for the ankle. (for complete versions and branch support values, see Extended Data Figs. 3–7).


For those interested in an "easy reading" account, the Smithsonian news report that linked me to this research article is a good one:

https://www.smithsonianmag.com/science-nature/the-ancestors-of-flying-pterosaurs-were-sleek-reptiles-that-ran-on-the-ground-180980898/
by Riley Black, Science Correspondent, October 5, 2022 11:00 a.m.


Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--
University of South Carolina
http://people.math.sc.edu/nyikos

[erik simpson]

Very good! Posts like this are most welcome.

[Daud Deden]

Scleromochlus taylori: The reptile was lightly-built, with longer hind legs than front legs, and over time paleontologists started to suspect that this little runner was an early forerunner of pterosaurs. The long legs and narrow feet of Scleromochlus, especially, resembled the legs and feet of pterosaurs.

[DD: I think it was terrestrio-arboreal, high-speed bipedal cursorial, low-speed quadrupedal, lightweight & longtailed like an arboreal gecko, with unusual feeding strategy.]

The emerging picture of the reptile is quite a bit different from its later relatives. In specific terms, Scleromochlus belonged to a group of reptiles called lagerpetids that have recently been associated with the origin of pterosaurs. The bones of Scleromochlus don’t show any specific adaptations to climbing, hopping [DD: lightweight & small!] or any sort of behavior that might be considered relevant to how pterosaurs evolved flight.

[Peter Nyikos]

On Wednesday, October 5, 2022 at 6:03:25 PM UTC-4, daud....@gmail.com wrote:
> On Wednesday, October 5, 2022 at 3:38:54 PM UTC-4, peter2...@gmail.com wrote:
> > A research article in the prestigious journal *Nature* gives new evidence for
> > the hypothesis that the "early Late Triassic" lagerpeptid *Scleromochlus*
> > is close to the direct ancestry of pterosaurs.
> >
> > Abstract
> > Mesozoic terrestrial ecosystems from their sudden appearance in the Late Triassic until their demise at the end of the Cretaceous [1],[2],[3],[4],[5],[6]. However, the origin and early evolution of pterosaurs are poorly understood owing to a substantial stratigraphic and morphological gap between these reptiles and their closest relatives [6], Lagerpetidae [7]. Scleromochlus taylori, a tiny reptile from the early Late Triassic of Scotland discovered over a century ago, was hypothesized to be a key taxon closely related to pterosaurs [8], but its poor preservation has limited previous studies and resulted in controversy over its phylogenetic position, with some even doubting its identification as an archosaur [9]. Here we use microcomputed tomographic scans to provide the first accurate whole-skeletal reconstruction and a revised diagnosis of Scleromochlus, revealing new anatomical details that conclusively identify it as a close pterosaur relative [1] within Pterosauromorpha (the lagerpetid + pterosaur clade). Scleromochlus is anatomically more similar to lagerpetids than to pterosaurs and retains numerous features that were probably present in very early diverging members of Avemetatarsalia (bird-line archosaurs). These results support the hypothesis that the first flying reptiles evolved from tiny, probably facultatively bipedal, cursorial ancestors [1].
> >
> > D. Foffa + 10 co-authors, "Scleromochlus and the early evolution of Pterosauromorpha, 05 October 2022,
> > https://www.nature.com/articles/s41586-022-05284-x
> >
> > Expertly illustrated, with a detailed reconstruction and:
> > Fig. 3: Time-calibrated strict consensus tree focused on Pterosauromorpha and different positions of S. taylori based on interpretations of the phylogenetic scores for the ankle. (for complete versions and branch support values, see Extended Data Figs. 3–7).
> >
> >
> > For those interested in an "easy reading" account, the Smithsonian news report that linked me to this research article is a good one:
> >
> > https://www.smithsonianmag.com/science-nature/the-ancestors-of-flying-pterosaurs-were-sleek-reptiles-that-ran-on-the-ground-180980898/
> > by Riley Black, Science Correspondent, October 5, 2022 11:00 a.m.

> Scleromochlus taylori: The reptile was lightly-built, with longer hind legs than front legs, and over time paleontologists started to suspect that this little runner was an early forerunner of pterosaurs. The long legs and narrow feet of Scleromochlus, especially, resembled the legs and feet of pterosaurs.
>
> [DD: I think it was terrestrio-arboreal, high-speed bipedal cursorial, low-speed quadrupedal, lightweight & longtailed like an arboreal gecko, with unusual feeding strategy.]

What do you envision that feeding strategy to be? I could find nothing about it
in either the Smithsonian article or the research article.

Otherwise, I agree with what you say.

> The emerging picture of the reptile is quite a bit different from its later relatives. In specific terms, Scleromochlus belonged to a group of reptiles called lagerpetids that have recently been associated with the origin of pterosaurs. The bones of Scleromochlus don’t show any specific adaptations to climbing, hopping [DD: lightweight & small!] or any sort of behavior that might be considered relevant to how pterosaurs evolved flight.

The idea of it having pads like a gecko for climbing is intriguing.
This would be a specific adaptation to climbing that does not show up in the bones.
It's not unique to geckos: we sometimes find tree frogs clinging to the glass on our windows.

Of course, this is speculation, but we can ask ourselves whether climbing trees
requires any special adaptations. We humans have no claws, only our fingers and toes,
but there are some good tree climbers among us. A close look at the illustrations
of the bones of manus and pes is in order.

At some point, there must be some way descendants can become gliders.
With birds, there is an age-old controversy about "ground-up" and "trees-down"
origins of flying, with the latter enjoying a slight advantage at present AFAIK.
Unless bird ancestors skipped the gliding stage altogether, they had to become
arboreal at some point.

With pterosaur ancestors, there seems no advantage in having a featherless patagium
for running (maybe hopping, but see above) and so a gliding stage with an arboreal lifestyle
seems almost necessary.

Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--

Univ. of South Carolina at Columbia
http://people.math.sc.edu/nyikos

[Daud Deden]

On Friday, October 7, 2022 at 8:04:14 AM UTC-4, peter2...@gmail.com wrote:
> On Wednesday, October 5, 2022 at 6:03:25 PM UTC-4, daud....@gmail.com wrote:
> > On Wednesday, October 5, 2022 at 3:38:54 PM UTC-4, peter2...@gmail.com wrote:
> > > A research article in the prestigious journal *Nature* gives new evidence for
> > > the hypothesis that the "early Late Triassic" lagerpeptid *Scleromochlus*
> > > is close to the direct ancestry of pterosaurs.
> > >
> > > Abstract
> > > Mesozoic terrestrial ecosystems from their sudden appearance in the Late Triassic until their demise at the end of the Cretaceous [1],[2],[3],[4],[5],[6]. However, the origin and early evolution of pterosaurs are poorly understood owing to a substantial stratigraphic and morphological gap between these reptiles and their closest relatives [6], Lagerpetidae [7]. Scleromochlus taylori, a tiny reptile from the early Late Triassic of Scotland discovered over a century ago, was hypothesized to be a key taxon closely related to pterosaurs [8], but its poor preservation has limited previous studies and resulted in controversy over its phylogenetic position, with some even doubting its identification as an archosaur [9]. Here we use microcomputed tomographic scans to provide the first accurate whole-skeletal reconstruction and a revised diagnosis of Scleromochlus, revealing new anatomical details that conclusively identify it as a close pterosaur relative [1] within Pterosauromorpha (the lagerpetid + pterosaur clade). Scleromochlus is anatomically more similar to lagerpetids than to pterosaurs and retains numerous features that were probably present in very early diverging members of Avemetatarsalia (bird-line archosaurs). These results support the hypothesis that the first flying reptiles evolved from tiny, probably facultatively bipedal, cursorial ancestors [1].
> > >
> > > D. Foffa + 10 co-authors, "Scleromochlus and the early evolution of Pterosauromorpha, 05 October 2022,
> > > https://www.nature.com/articles/s41586-022-05284-x
> > >
> > > Expertly illustrated, with a detailed reconstruction and:
> > > Fig. 3: Time-calibrated strict consensus tree focused on Pterosauromorpha and different positions of S. taylori based on interpretations of the phylogenetic scores for the ankle. (for complete versions and branch support values, see Extended Data Figs. 3–7).
> > >
> > >
> > > For those interested in an "easy reading" account, the Smithsonian news report that linked me to this research article is a good one:
> > >
> > > https://www.smithsonianmag.com/science-nature/the-ancestors-of-flying-pterosaurs-were-sleek-reptiles-that-ran-on-the-ground-180980898/
> > > by Riley Black, Science Correspondent, October 5, 2022 11:00 a.m.
>
> > Scleromochlus taylori: The reptile was lightly-built, with longer hind legs than front legs, and over time paleontologists started to suspect that this little runner was an early forerunner of pterosaurs. The long legs and narrow feet of Scleromochlus, especially, resembled the legs and feet of pterosaurs.
> >
> > [DD: I think it was terrestrio-arboreal, high-speed bipedal cursorial, low-speed quadrupedal, lightweight & longtailed like an arboreal gecko, with unusual feeding strategy.]
> What do you envision that feeding strategy to be? I could find nothing about it
> in either the Smithsonian article or the research article.

I don't know. Something different from a typical reptile of similar form. I am wondering if there might be a very loose parallel to the aye-aye lemur, a very long finger evolved and used to tap (and echolocate - possible in pterosaurs?) wood beetle larvae, then developing a taste for slow flying insects, using the long finger to spear/slash/fan them towards the mouth, with fanning becoming more and more useful and digital lengthening until it assisted (fanning downwards) in vertical tree trunk climbing, then flight.

Plausible?

> Otherwise, I agree with what you say.
> > The emerging picture of the reptile is quite a bit different from its later relatives. In specific terms, Scleromochlus belonged to a group of reptiles called lagerpetids that have recently been associated with the origin of pterosaurs. The bones of Scleromochlus don’t show any specific adaptations to climbing, hopping [DD: lightweight & small!] or any sort of behavior that might be considered relevant to how pterosaurs evolved flight.
> The idea of it having pads like a gecko for climbing is intriguing.
> This would be a specific adaptation to climbing that does not show up in the bones.
> It's not unique to geckos: we sometimes find tree frogs clinging to the glass on our windows.
>
> Of course, this is speculation, but we can ask ourselves whether climbing trees
> requires any special adaptations. We humans have no claws, only our fingers and toes,
> but there are some good tree climbers among us. A close look at the illustrations
> of the bones of manus and pes is in order.
>
> At some point, there must be some way descendants can become gliders.

We disagree on that. Gliding is a separate specialization vs powered flight (flapping/fanning)

[Peter Nyikos]

Sorry to be so late with this, Daud. I've been very busy in talk.origins
countering a lot of anti-ID propaganda and propaganda about a
crucially important but off-toic issue. Even now I am short on time.

On Friday, October 7, 2022 at 5:04:22 PM UTC-4, daud....@gmail.com wrote:
> On Friday, October 7, 2022 at 8:04:14 AM UTC-4, peter2...@gmail.com wrote:
> > On Wednesday, October 5, 2022 at 6:03:25 PM UTC-4, daud....@gmail.com wrote:
> > > On Wednesday, October 5, 2022 at 3:38:54 PM UTC-4, peter2...@gmail.com wrote:
> > > > A research article in the prestigious journal *Nature* gives new evidence for
> > > > the hypothesis that the "early Late Triassic" lagerpeptid *Scleromochlus*
> > > > is close to the direct ancestry of pterosaurs.
> > > >
> > > > Abstract
> > > > Mesozoic terrestrial ecosystems from their sudden appearance in the Late Triassic until their demise at the end of the Cretaceous [1],[2],[3],[4],[5],[6]. However, the origin and early evolution of pterosaurs are poorly understood owing to a substantial stratigraphic and morphological gap between these reptiles and their closest relatives [6], Lagerpetidae [7]. Scleromochlus taylori, a tiny reptile from the early Late Triassic of Scotland discovered over a century ago, was hypothesized to be a key taxon closely related to pterosaurs [8],

In fact, the hypothesis itself is over a century old: reference [8] is to a 1914 paper.

> but its poor preservation has limited previous studies and resulted in controversy over its phylogenetic position, with some even doubting its identification as an archosaur [9]. Here we use microcomputed tomographic scans to provide the first accurate whole-skeletal reconstruction and a revised diagnosis of Scleromochlus, revealing new anatomical details that conclusively identify it as a close pterosaur relative [1] within Pterosauromorpha (the lagerpetid + pterosaur clade). Scleromochlus is anatomically more similar to lagerpetids than to pterosaurs and retains numerous features that were probably present in very early diverging members of Avemetatarsalia (bird-line archosaurs). These results support the hypothesis that the first flying reptiles evolved from tiny, probably facultatively bipedal, cursorial ancestors [1].
> > > >
> > > > D. Foffa + 10 co-authors, "Scleromochlus and the early evolution of Pterosauromorpha, 05 October 2022,
> > > > https://www.nature.com/articles/s41586-022-05284-x
> > > >
> > > > Expertly illustrated, with a detailed reconstruction and:
> > > > Fig. 3: Time-calibrated strict consensus tree focused on Pterosauromorpha and different positions of S. taylori based on interpretations of the phylogenetic scores for the ankle. (for complete versions and branch support values, see Extended Data Figs. 3–7).
> > > >
> > > >
> > > > For those interested in an "easy reading" account, the Smithsonian news report that linked me to this research article is a good one:
> > > >
> > > > https://www.smithsonianmag.com/science-nature/the-ancestors-of-flying-pterosaurs-were-sleek-reptiles-that-ran-on-the-ground-180980898/
> > > > by Riley Black, Science Correspondent, October 5, 2022 11:00 a.m.

Here is where you came in, Daud:

> > > Scleromochlus taylori: The reptile was lightly-built, with longer hind legs than front legs, and over time paleontologists started to suspect that this little runner was an early forerunner of pterosaurs. The long legs and narrow feet of Scleromochlus, especially, resembled the legs and feet of pterosaurs.
> > >
> > > [DD: I think it was terrestrio-arboreal, high-speed bipedal cursorial, low-speed quadrupedal, lightweight & longtailed like an arboreal gecko, with unusual feeding strategy.]
> > What do you envision that feeding strategy to be? I could find nothing about it
> > in either the Smithsonian article or the research article.

> I don't know. Something different from a typical reptile of similar form. I am wondering if there might be a very loose parallel to the aye-aye lemur, a very long finger evolved and used to tap (and echolocate - possible in pterosaurs?) wood beetle larvae, then developing a taste for slow flying insects, using the long finger to spear/slash/fan them towards the mouth, with fanning becoming more and more useful and digital lengthening until it assisted (fanning downwards) in vertical tree trunk climbing, then flight.

That would be the fourth finger, the "little finger" having vanished early. Strangely enough, I could
find no pictures of the manus (hand) bones, of Scleromochlus in the Nature article (nor in the Smithsonian report),
only a picture of the pes (foot) bones. And, disappointingly enough, there is no trace of a fifth toe,
although there is a big fifth toe in a generic pterosaur foot reproduction.

I'll have to look further into this on this weekend.

>
> Plausible?

Well, it seems like your idea first takes the descendants away from progress towards
a wing and towards a narrow finger. Then somehow the flight membrane is supposed to take shape
and make the digit unsuitable for probing for grubs. I don't claim it is impossible,
but you'd have to come up with reasons for the reversal that don't make
some of the steps maladaptive.

> > Otherwise, I agree with what you say.

> > > The emerging picture of the reptile is quite a bit different from its later relatives. In specific terms, Scleromochlus belonged to a group of reptiles called lagerpetids that have recently been associated with the origin of pterosaurs. The bones of Scleromochlus don’t show any specific adaptations to climbing, hopping [DD: lightweight & small!] or any sort of behavior that might be considered relevant to how pterosaurs evolved flight.

> > The idea of it having pads like a gecko for climbing is intriguing.
> > This would be a specific adaptation to climbing that does not show up in the bones.
> > It's not unique to geckos: we sometimes find tree frogs clinging to the glass on our windows.
> >
> > Of course, this is speculation, but we can ask ourselves whether climbing trees
> > requires any special adaptations. We humans have no claws, only our fingers and toes,
> > but there are some good tree climbers among us. A close look at the illustrations
> > of the bones of manus and pes is in order.

Or maybe it is unnecessary. One does not think of hooves as being good for
tree climbing, but take a look at the following picture, where goats are all over a tree:

https://www.bing.com/spotlight?spotlightId=EssaouiraCoastMorocco&q=Goats%20feeding%20in%20an%20argan%20tree%20near%20Essouira,%20Morocco&carindexpill=0&carindeximg=3&textorimgcar=img&isfullscreen=false&carscrlimgv2=564&form=SLVCAR&ssid=70f80aeb-dadf-b744-30f3-cea7fe3e7a8f

and here is a whole gallery of such pictures:

https://www.bing.com/search?q=%2bGoats+feeding+in+an+argan+tree+near+Essouira%2c+Morocco&filters=rcrse%3a%221%22&FORM=RCRE

> >
> > At some point, there must be some way descendants can become gliders.
> We disagree on that. Gliding is a separate specialization vs powered flight (flapping/fanning)

I'm not talking about highly skilled gliding, just the use of narrow membranes to
let the creature down more slowly as it falls. That's how pterosaur wings
have to start, barring "hopeful monsters".

> > With birds, there is an age-old controversy about "ground-up" and "trees-down"
> > origins of flying, with the latter enjoying a slight advantage at present AFAIK.
> > Unless bird ancestors skipped the gliding stage altogether, they had to become
> > arboreal at some point.
> >
> > With pterosaur ancestors, there seems no advantage in having a featherless patagium
> > for running (maybe hopping, but see above) and so a gliding stage with an arboreal lifestyle
> > seems almost necessary.

Note, I wrote "almost" here and ought to have written it up there also.

Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--

Univ. of South Carolina in Columbia
http://people.math.sc.edu/nyikos

[Daud Deden]

What progress toward a wing?

and towards a narrow finger.

No, an extended finger, thin or thick.

Then somehow the flight membrane is supposed to take shape
> and make the digit unsuitable for probing for grubs.

Was the big finger of small early pterosaurs unable to be used to dig out grubs from softened wood? Would a partial membrane interfere with access? Did they have long claws? Did they have advanced hearing & balance organs?

I don't claim it is impossible,
> but you'd have to come up with reasons for the reversal that don't make
> some of the steps maladaptive.
> > > Otherwise, I agree with what you say.
>
> > > > The emerging picture of the reptile is quite a bit different from its later relatives. In specific terms, Scleromochlus belonged to a group of reptiles called lagerpetids that have recently been associated with the origin of pterosaurs. The bones of Scleromochlus don’t show any specific adaptations to climbing, hopping [DD: lightweight & small!] or any sort of behavior that might be considered relevant to how pterosaurs evolved flight.
>
> > > The idea of it having pads like a gecko for climbing is intriguing.
> > > This would be a specific adaptation to climbing that does not show up in the bones.
> > > It's not unique to geckos: we sometimes find tree frogs clinging to the glass on our windows.
> > >
> > > Of course, this is speculation, but we can ask ourselves whether climbing trees
> > > requires any special adaptations. We humans have no claws, only our fingers and toes,
> > > but there are some good tree climbers among us. A close look at the illustrations
> > > of the bones of manus and pes is in order.
> Or maybe it is unnecessary. One does not think of hooves as being good for
> tree climbing, but take a look at the following picture, where goats are all over a tree:

Those were placed, posed & pic'd by crews for good tourist money. Goats can climb steeply.

> https://www.bing.com/spotlight?spotlightId=EssaouiraCoastMorocco&q=Goats%20feeding%20in%20an%20argan%20tree%20near%20Essouira,%20Morocco&carindexpill=0&carindeximg=3&textorimgcar=img&isfullscreen=false&carscrlimgv2=564&form=SLVCAR&ssid=70f80aeb-dadf-b744-30f3-cea7fe3e7a8f
>
> and here is a whole gallery of such pictures:
>
> https://www.bing.com/search?q=%2bGoats+feeding+in+an+argan+tree+near+Essouira%2c+Morocco&filters=rcrse%3a%221%22&FORM=RCRE
> > >
> > > At some point, there must be some way descendants can become gliders.
> > We disagree on that. Gliding is a separate specialization vs powered flight (flapping/fanning)
> I'm not talking about highly skilled gliding, just the use of narrow membranes to
> let the creature down more slowly as it falls.

Here in a Miami pine forest, I constantly get bombarded by geckos leaping from branches down to bugs below, no membrane, but possibly outstretched hands. They are never injured upon contact, being so light. The iguanas sometimes fall, being heavier they get stunned.

That's how pterosaur wings
> have to start, barring "hopeful monsters".
> > > With birds, there is an age-old controversy about "ground-up" and "trees-down"
> > > origins of flying, with the latter enjoying a slight advantage at present AFAIK.
> > > Unless bird ancestors skipped the gliding stage altogether, they had to become
> > > arboreal at some point.
> > >
> > > With pterosaur ancestors, there seems no advantage in having a featherless patagium
> > > for running (maybe hopping, but see above) and so a gliding stage with an arboreal lifestyle
> > > seems almost necessary.

I can imagine flat palms might help a proto-flying arborealist. But it would be parachuting more than gliding.

> Note, I wrote "almost" here and ought to have written it up there also.
> Peter Nyikos
> Professor, Dept. of Mathematics -- standard disclaimer--
> Univ. of South Carolina in Columbia
> http://people.math.sc.edu/nyikos

The ayeaye was just an example of an arboreal scansoreal animal with an extended finger, used in food insect acquisition. Pterosaurs did not follow that exact path.

[Peter Nyikos]

Why, lengthening of the 4th finger [see above] to produce the wings we see
in pterosaurs, which are the result of a wide membrane attached to the finger.

> and towards a narrow finger.
> No, an extended finger, thin or thick.

The aye-aye's middle finger is not only longer than the others, it
is also thinner to be able to fit it into small crevices to spear the grubs.
I thought you had this in mind earlier.

> >Then somehow the flight membrane is supposed to take shape
> > and make the digit unsuitable for probing for grubs.

> Was the big finger of small early pterosaurs unable to be used to dig out grubs from softened wood?

Like bats, pterosaurs are found in "fully developed form," with a complete lack of fossils of the
intermediate stages from animals with no side membranes. So the answer is Yes, for "unable."

> Would a partial membrane interfere with access? Did they have long claws? Did they have advanced hearing & balance organs?

Yes to all except long claws on the wings. Take a look at any full pterosaur skeleton.

> >I don't claim it is impossible,
> > but you'd have to come up with reasons for the reversal that don't make
> > some of the steps maladaptive.

This is a less formidable problem than for bats, for whom no one
has been able to even *imagine* a sequence without maladaptive stages.
I talked about this recently in talk.origins and could show you what
I wrote if you are interested.

> > > > Otherwise, I agree with what you say.
> >
> > > > > The emerging picture of the reptile is quite a bit different from its later relatives. In specific terms, Scleromochlus belonged to a group of reptiles called lagerpetids that have recently been associated with the origin of pterosaurs. The bones of Scleromochlus don’t show any specific adaptations to climbing, hopping [DD: lightweight & small!] or any sort of behavior that might be considered relevant to how pterosaurs evolved flight.
> >
> > > > The idea of it having pads like a gecko for climbing is intriguing.
> > > > This would be a specific adaptation to climbing that does not show up in the bones.
> > > > It's not unique to geckos: we sometimes find tree frogs clinging to the glass on our windows.
> > > >
> > > > Of course, this is speculation, but we can ask ourselves whether climbing trees
> > > > requires any special adaptations. We humans have no claws, only our fingers and toes,
> > > > but there are some good tree climbers among us. A close look at the illustrations
> > > > of the bones of manus and pes is in order.
> > Or maybe it is unnecessary. One does not think of hooves as being good for
> > tree climbing, but take a look at the following picture, where goats are all over a tree:

> Those were placed, posed & pic'd by crews for good tourist money. Goats can climb steeply.

But not steeply enough to climb those trees ("placed")? I'm not sure what you are saying here.

> > https://www.bing.com/spotlight?spotlightId=EssaouiraCoastMorocco&q=Goats%20feeding%20in%20an%20argan%20tree%20near%20Essouira,%20Morocco&carindexpill=0&carindeximg=3&textorimgcar=img&isfullscreen=false&carscrlimgv2=564&form=SLVCAR&ssid=70f80aeb-dadf-b744-30f3-cea7fe3e7a8f
> >
> > and here is a whole gallery of such pictures:
> >
> > https://www.bing.com/search?q=%2bGoats+feeding+in+an+argan+tree+near+Essouira%2c+Morocco&filters=rcrse%3a%221%22&FORM=RCRE
> > > >
> > > > At some point, there must be some way descendants can become gliders.
> > > We disagree on that. Gliding is a separate specialization vs powered flight (flapping/fanning)

> > I'm not talking about highly skilled gliding, just the use of narrow membranes to
> > let the creature down more slowly as it falls.

Iguanas might benefit from narrow membranes, as you seem to suggest next.

> Here in a Miami pine forest, I constantly get bombarded by geckos leaping from branches down to bugs below, no membrane, but possibly outstretched hands. They are never injured upon contact, being so light. The iguanas sometimes fall, being heavier they get stunned.

> > That's how pterosaur wings
> > have to start, barring "hopeful monsters".

> > > > With birds, there is an age-old controversy about "ground-up" and "trees-down"
> > > > origins of flying, with the latter enjoying a slight advantage at present AFAIK.
> > > > Unless bird ancestors skipped the gliding stage altogether, they had to become
> > > > arboreal at some point.
> > > >
> > > > With pterosaur ancestors, there seems no advantage in having a featherless patagium
> > > > for running (maybe hopping, but see above) and so a gliding stage with an arboreal lifestyle
> > > > seems almost necessary.
> I can imagine flat palms might help a proto-flying arborealist. But it would be parachuting more than gliding.

Agreed. Note, people can steer parachutes, but it's not like hang gliding.

> > Note, I wrote "almost" here and ought to have written it up there also.
> > Peter Nyikos
> > Professor, Dept. of Mathematics -- standard disclaimer--
> > Univ. of South Carolina in Columbia
> > http://people.math.sc.edu/nyikos

> The ayeaye was just an example of an arboreal scansoreal animal with an extended finger, used in food insect acquisition. Pterosaurs did not follow that exact path.

Do you have any more ideas about what the exact path might have been?

Peter Nyikos
Professor, Dept. of Mathematics

Univ. of South Carolina -- standard disclaimer--
http://people.math.sc.edu/nyikos

[Daud Deden]

But Scleromuchlus had normal hands. I meant between Scleromuchlos and early pterosaurs, a finger extended evolutionarily as it fed on beetle larvae on trees, which also may have helped grip branches. An interdigital membrane could have been selected for if it also fanned flying insects toward it, a predecessor for flapping flight.

> > and towards a narrow finger.
> > No, an extended finger, thin or thick.
> The aye-aye's middle finger is not only longer than the others, it
> is also thinner to be able to fit it into small crevices to spear the grubs.

Yes.

> I thought you had this in mind earlier.
> > >Then somehow the flight membrane is supposed to take shape
> > > and make the digit unsuitable for probing for grubs.

A flapping predator got a new empty niche with numerous flying insect prey and little competition, becoming more selected for adult predation.

> > Was the big finger of small early pterosaurs unable to be used to dig out grubs from softened wood?
> Like bats, pterosaurs are found in "fully developed form," with a complete lack of fossils of the
> intermediate stages from animals with no side membranes. So the answer is Yes, for "unable."

How do you know that? Side membranes of the finger or the torso?

> > Would a partial membrane interfere with access? Did they have long claws? Did they have advanced hearing & balance organs?
> Yes to all except long claws on the wings. Take a look at any full pterosaur skeleton.
> > >I don't claim it is impossible,
> > > but you'd have to come up with reasons for the reversal that don't make
> > > some of the steps maladaptive.
> This is a less formidable problem than for bats, for whom no one
> has been able to even *imagine* a sequence without maladaptive stages.
> I talked about this recently in talk.origins and could show you what
> I wrote if you are interested.
> > > > > Otherwise, I agree with what you say.
> > >
> > > > > > The emerging picture of the reptile is quite a bit different from its later relatives. In specific terms, Scleromochlus belonged to a group of reptiles called lagerpetids that have recently been associated with the origin of pterosaurs. The bones of Scleromochlus don’t show any specific adaptations to climbing, hopping [DD: lightweight & small!] or any sort of behavior that might be considered relevant to how pterosaurs evolved flight.
> > >
> > > > > The idea of it having pads like a gecko for climbing is intriguing.
> > > > > This would be a specific adaptation to climbing that does not show up in the bones.
> > > > > It's not unique to geckos: we sometimes find tree frogs clinging to the glass on our windows.
> > > > >
> > > > > Of course, this is speculation, but we can ask ourselves whether climbing trees
> > > > > requires any special adaptations.

Both Scleromuchlus and geckos have light small body, humans don't.

We humans have no claws, only our fingers and toes,
> > > > > but there are some good tree climbers among us. A close look at the illustrations
> > > > > of the bones of manus and pes is in order.
> > > Or maybe it is unnecessary. One does not think of hooves as being good for
> > > tree climbing, but take a look at the following picture, where goats are all over a tree:
>
> > Those were placed, posed & pic'd by crews for good tourist money. Goats can climb steeply.
> But not steeply enough to climb those trees ("placed")? I'm not sure what you are saying here.

Just that the goats may have put there to draw tourists.

> > > https://www.bing.com/spotlight?spotlightId=EssaouiraCoastMorocco&q=Goats%20feeding%20in%20an%20argan%20tree%20near%20Essouira,%20Morocco&carindexpill=0&carindeximg=3&textorimgcar=img&isfullscreen=false&carscrlimgv2=564&form=SLVCAR&ssid=70f80aeb-dadf-b744-30f3-cea7fe3e7a8f
> > >
> > > and here is a whole gallery of such pictures:
> > >
> > > https://www.bing.com/search?q=%2bGoats+feeding+in+an+argan+tree+near+Essouira%2c+Morocco&filters=rcrse%3a%221%22&FORM=RCRE
> > > > >
> > > > > At some point, there must be some way descendants can become gliders.
> > > > We disagree on that. Gliding is a separate specialization vs powered flight (flapping/fanning)
>
> > > I'm not talking about highly skilled gliding, just the use of narrow membranes to
> > > let the creature down more slowly as it falls.
> Iguanas might benefit from narrow membranes, as you seem to suggest next.

But neither geckos nor iguanas have them.

> > Here in a Miami pine forest, I constantly get bombarded by geckos leaping from branches down to bugs below, no membrane, but possibly outstretched hands. They are never injured upon contact, being so light. The iguanas sometimes fall, being heavier they get stunned.
>
> > > That's how pterosaur wings
> > > have to start, barring "hopeful monsters".
>
> > > > > With birds, there is an age-old controversy about "ground-up" and "trees-down"
> > > > > origins of flying, with the latter enjoying a slight advantage at present AFAIK.
> > > > > Unless bird ancestors skipped the gliding stage altogether, they had to become
> > > > > arboreal at some point.
> > > > >
> > > > > With pterosaur ancestors, there seems no advantage in having a featherless patagium
> > > > > for running (maybe hopping, but see above) and so a gliding stage with an arboreal lifestyle
> > > > > seems almost necessary.
> > I can imagine flat palms might help a proto-flying arborealist. But it would be parachuting more than gliding.
> Agreed. Note, people can steer parachutes, but it's not like hang gliding.
> > > Note, I wrote "almost" here and ought to have written it up there also.
> > > Peter Nyikos
> > > Professor, Dept. of Mathematics -- standard disclaimer--
> > > Univ. of South Carolina in Columbia
> > > http://people.math.sc.edu/nyikos
>
> > The ayeaye was just an example of an arboreal scansoreal animal with an extended finger, used in food insect acquisition. Pterosaurs did not follow that exact path.
> Do you have any more ideas about what the exact path might have been?
> Peter Nyikos
> Professor, Dept. of Mathematics
> Univ. of South Carolina -- standard disclaimer--
> http://people.math.sc.edu/nyikos

Not better. Having a long muscular finger may have been the first step towards flight.

[Peter Nyikos]

That works for bats, but the interdigital membrane would have to disappear
en route to the pterosaurs that we know from fossils, while the membrane on
the outside of the fourth finger would have to creep up to attach to its entire length.

Lots of unexplained reversals here.

> > > and towards a narrow finger.
> > > No, an extended finger, thin or thick.
> > The aye-aye's middle finger is not only longer than the others, it
> > is also thinner to be able to fit it into small crevices to spear the grubs.
> Yes.
> > I thought you had this in mind earlier.
> > > >Then somehow the flight membrane is supposed to take shape
> > > > and make the digit unsuitable for probing for grubs.
> A flapping predator got a new empty niche with numerous flying insect prey and little competition, becoming more selected for adult predation.

Again, that works for bats. But for them, there is a clumsiness in getting around and
grabbing things that doesn't work for any of the pterosaurs, who have three good
free digits while bats have only the pollex (thumb).

> > > Was the big finger of small early pterosaurs unable to be used to dig out grubs from softened wood?

> > Like bats, pterosaurs are found in "fully developed form," with a complete lack of fossils of the
> > intermediate stages from animals with no side membranes. So the answer is Yes, for "unable."

> How do you know that? Side membranes of the finger or the torso?

None known outside of the pterosaurs themselves.

Back in 1975, Bakker published what looked like a promising ancestor:
a completely imaginary reproduction of what was then called Podopteryx
and since has been renamed Sharovipteryx: a colugo with a head like Pterodactylus.

He got it all wrong: the patagium was almost everywhere except
where the patagium of a pterosaur is most needed.
--https://en.wikipedia.org/wiki/Sharovipteryx

> > > Would a partial membrane interfere with access? Did they have long claws? Did they have advanced hearing & balance organs?

> > Yes to all except long claws on the wings. Take a look at any full pterosaur skeleton.

> > > >I don't claim it is impossible,
> > > > but you'd have to come up with reasons for the reversal that don't make
> > > > some of the steps maladaptive.

Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--

University of So. Carolina at Columbia
http://people.math.sc.edu/nyikos

PS I've left in the rest, in case you might want me to address
anything you wrote this time around.

[Daud Deden]

There is membrane on front and rear of the flight finger. I don't see any reversals.
https://www.google.com/search?q=pterosaur+interdigital+membrane&rlz=1C1GCEB_enUS1028US1028&oq=pterosaur+interdigital+membrane&aqs=chrome..69i57.9271j0j15&sourceid=chrome&ie=UTF-8&safe=active&ssui=on#imgrc=eSuSMACXqnpA9M

> Lots of unexplained reversals here.
> > > > and towards a narrow finger.
> > > > No, an extended finger, thin or thick.
> > > The aye-aye's middle finger is not only longer than the others, it
> > > is also thinner to be able to fit it into small crevices to spear the grubs.
> > Yes.
> > > I thought you had this in mind earlier.
> > > > >Then somehow the flight membrane is supposed to take shape
> > > > > and make the digit unsuitable for probing for grubs.
> > A flapping predator got a new empty niche with numerous flying insect prey and little competition, becoming more selected for adult predation.
> Again, that works for bats.

I am referring to pterosaur evolution.

But for them, there is a clumsiness in getting around and
> grabbing things that doesn't work for any of the pterosaurs, who have three good
> free digits while bats have only the pollex (thumb).
> > > > Was the big finger of small early pterosaurs unable to be used to dig out grubs from softened wood?
>
> > > Like bats, pterosaurs are found in "fully developed form," with a complete lack of fossils of the
> > > intermediate stages from animals with no side membranes. So the answer is Yes, for "unable."
>
> > How do you know that? Side membranes of the finger or the torso?
> None known outside of the pterosaurs themselves.

No problem then.

> Back in 1975, Bakker published what looked like a promising ancestor:
> a completely imaginary reproduction of what was then called Podopteryx
> and since has been renamed Sharovipteryx: a colugo with a head like Pterodactylus.

Colugo = glider, never a flapper. Wrong direction.

> He got it all wrong: the patagium was almost everywhere except
> where the patagium of a pterosaur is most needed.
> --https://en.wikipedia.org/wiki/Sharovipteryx

Fanning = flapping.

DD

[Daud Deden]

I figure that no pterosaurs, avians nor scleromuchlus had prehensile tails or were habitual gliders.
Ecology plays a part in developing those traits.

Evolution
One point of interest is the distribution of animals with prehensile tails. The prehensile tail is predominantly a New World adaptation, especially among mammals.[1] Many more animals in South America have prehensile tails than in Africa and Southeast Asia. It has been argued that animals with prehensile tails are more common in South America because the forest there is denser than in Africa or Southeast Asia.[3] In contrast, less dense forests such as in Southeast Asia have been observed to have more abundant gliding animals such as colugos or flying snakes; few gliding vertebrates are found in South America. South American rainforests also differ by having more lianas, as there are fewer large animals to eat them than in Africa and Asia; the presence of lianas may aid climbers but obstruct gliders.[4] Curiously, Australia-New Guinea contains many mammals with prehensile tails and also many mammals which can glide; in fact, all Australian mammalian gliders have tails that are prehensile to an extent

[Peter Nyikos]

On Monday, October 24, 2022 at 10:31:02 AM UTC-4, daud....@gmail.com wrote:
> On Friday, October 21, 2022 at 2:57:10 PM UTC-4, Daud Deden wrote:
> > On Friday, October 21, 2022 at 11:37:53 AM UTC-4, peter2...@gmail.com wrote:
> > > On Monday, October 17, 2022 at 10:08:07 PM UTC-4, daud....@gmail.com wrote:

> > > > But Scleromuchlus had normal hands. I meant between Scleromuchlos and early pterosaurs, a finger extended evolutionarily as it fed on beetle larvae on trees, which also may have helped grip branches. An interdigital membrane could have been selected for if it also fanned flying insects toward it, a predecessor for flapping flight.

> > > That works for bats, but the interdigital membrane would have to disappear
> > > en route to the pterosaurs that we know from fossils, while the membrane on
> > > the outside of the fourth finger would have to creep up to attach to its entire length.

> > There is membrane on front and rear of the flight finger. I don't see any reversals.
> > https://www.google.com/search?q=pterosaur+interdigital+membrane&rlz=1C1GCEB_enUS1028US1028&oq=pterosaur+interdigital+membrane&aqs=chrome..69i57.9271j0j15&sourceid=chrome&ie=UTF-8&safe=active&ssui=on#imgrc=eSuSMACXqnpA9M

The membranes don't extend to the other digits, do they?
I was talking about membranes between digits.

> > > Lots of unexplained reversals here.

<snip of earlier talk>

> > > > A flapping predator got a new empty niche with numerous flying insect prey and little competition, becoming more selected for adult predation.

> > > Again, that works for bats.

> > I am referring to pterosaur evolution.

But with the assumption that there were membranes between the fingers, as with bats,
which is what catching insects are for.

> > > But for them, there is a clumsiness in getting around and
> > > grabbing things that doesn't work for any of the pterosaurs, who have three good
> > > free digits while bats have only the pollex (thumb).

[I had written:]

> > > > > Like bats, pterosaurs are found in "fully developed form," with a complete lack of fossils of the

> > > > > intermediate stages from animals with no side membranes. [...]

> > >
> > > > How do you know that? Side membranes of the finger or the torso?

> > > None known outside of the pterosaurs themselves.

> > No problem then.

Except that we are totally lacking plausible intermediates.
This is also true of bats, but there the situation is even worse
as far as *imagining* what the intermediates might have looked like.
With pterosaurs, it is easy to imagine them; with bats, every proposed
hypothetical sequence includes changes that seem maladaptive.

> > > Back in 1975, Bakker published what looked like a promising ancestor:
> > > a completely imaginary reproduction of what was then called Podopteryx
> > > and since has been renamed Sharovipteryx: a colugo with a head like Pterodactylus.

> > Colugo = glider, never a flapper. Wrong direction.

According to one widely accepted belief, yes. But what is
the basis for that belief? All I've seen so far is the say-so of Padian,
who was wrong about pterosaurs having been bipedal.

> > > He got it all wrong: the patagium was almost everywhere except
> > > where the patagium of a pterosaur is most needed.
> > > --https://en.wikipedia.org/wiki/Sharovipteryx

> > Fanning = flapping.

Why the equals sign? fanning is either primarily horizontal or primarily towards the face;
flapping for flight is primarily up and down.


towards flight.


<snip of a bunch of earlier talk>

> I figure that no pterosaurs, avians nor scleromuchlus had prehensile tails or were habitual gliders.
> Ecology plays a part in developing those traits.

What do you hypothesize to have been absent from the ecology of the examples you give?

>
> Evolution
> One point of interest is the distribution of animals with prehensile tails. The prehensile tail is predominantly a New World adaptation, especially among mammals.[1]

This is strange, considering what it says about Australia and New Guinea below.
I always thought the New World was confined to the Western hemisphere.

> Many more animals in South America have prehensile tails than in Africa and Southeast Asia. It has been argued that animals with prehensile tails are more common in South America because the forest there is denser than in Africa or Southeast Asia.[3] In contrast, less dense forests such as in Southeast Asia have been observed to have more abundant gliding animals such as colugos or flying snakes; few gliding vertebrates are found in South America. South American rainforests also differ by having more lianas, as there are fewer large animals to eat them than in Africa and Asia; the presence of lianas may aid climbers but obstruct gliders.[4] Curiously, Australia-New Guinea contains many mammals with prehensile tails and also many mammals which can glide; in fact, all Australian mammalian gliders have tails that are prehensile to an extent

The end got cut off before you got to the point where it talked about forests where neither
gliders nor animals with prehensile tails are found. Or did it talk about them at all?

Worse yet, it got cut off before you could give a reference for this.


Peter Nyikos

[Daud Deden]

Wikipedia article on prehensile tail evolution.
I'll have to get back later. DD

>
> Peter Nyikos

[Daud Deden]

I retract my conjecture on proto-pterosaurs having a single long digit similar to aye-ayes, as I don't think an interdigital membrane would be selected for, based on aye-aye nose picking.
https://www.malaymail.com/news/life/2022/11/01/take-your-pick-aye-aye-joins-ranks-of-snot-eaters/36875

[Peter Nyikos]

Me too. This is an extraordinarily busy week for me, but things should ease off next
week and I'll look at the Wiki article and tell you what I think about it.

By the way, talk.origins seems to be down. If it continues down for another day
we may see s.b.p. becoming "talk.origins in exile" again. I'm quite supportive of
such developments, as long as people don't linger here without contributing on-topic for s.b.p.
once talk.origins is back up.


Peter Nyikos

[Daud Deden]

African pterosaur
-likely spent time flying above open-water environments and diving to feed, like gannets and brown pelicans do today," Jacobs said. "Epapatelo otyikokolo was not a small animal, and its wingspan was approximately 4.8 m, or nearly 16 feet."

But fossils discovered since the study suggest that some of the newly identified pterosaur species could have been even larger creatures, Polcyn said. Pterosaurs were impressive creatures, with some of the largest species having wingspans of nearly 35 feet.

https://www.sciencedaily.com/releases/2022/11/221109151941.htm

The genus name 'Epapatelo' is the translation of the word from the Angolan Nhaneca dialect meaning "wing," and the species name "otyikokolo" is the translation of 'lizard.' The Nhaneca or Nyaneka people are an Indigenous group from Angola's Namibe Province, the region where the fossils were found

[Peter Nyikos]

Thanks for keeping this thread going during my 12 day absence, Daud.
I've been struggling with a bad cold and deadlines for most of that time.
But I came across an open access article over the weekend that looks relevant to what we've
been talking about.

On Thursday, November 10, 2022 at 9:33:42 PM UTC-5, daud....@gmail.com wrote:
> On Wednesday, November 2, 2022 at 6:06:57 PM UTC-4, peter2...@gmail.com wrote:
> > On Thursday, October 27, 2022 at 7:45:47 PM UTC-4, daud....@gmail.com wrote:

> > > On Wednesday, October 26, 2022 at 10:13:12 AM UTC-4, peter2...@gmail.-com wrote:
> > > > On Monday, October 24, 2022 at 10:31:02 AM UTC-4, daud....@gmail.com wrote:
> > > > > On Friday, October 21, 2022 at 2:57:10 PM UTC-4, Daud Deden wrote:
> > > > > > On Friday, October 21, 2022 at 11:37:53 AM UTC-4, peter2...@gmail.com wrote:
> > > > > > > On Monday, October 17, 2022 at 10:08:07 PM UTC-4, daud....@gmail.com wrote:
> > > >
> > > > > > > > But Scleromuchlus had normal hands. I meant between Scleromuchlos and early pterosaurs, a finger extended evolutionarily as it fed on beetle larvae on trees, which also may have helped grip branches. An interdigital membrane could have been selected for if it also fanned flying insects toward it, a predecessor for flapping flight.

After a long back-and-forth, you retreated from this hypothesis in your last post before
the one to which I am replying here:

"I retract my conjecture on proto-pterosaurs having a single long digit similar to aye-ayes, as I don't think an interdigital membrane would be selected for, based on aye-aye nose picking."

https://groups.google.com/g/talk.origins/c/e31xp8nnUEc

Fortunately, the following link opens a new door to the development of flight in some pterosaurs:ss

Current Biology, VOLUME 31, ISSUE 11, P2429-2436.E7, JUNE 07, 2021:
"A new darwinopteran pterosaur reveals arborealism and an opposed thumb"
https://www.cell.com/current-biology/fulltext/S0960-9822(21)00369-9?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0960982221003699%3Fshowall%3Dtrue
Excerpt:
"The new species exhibits the oldest record of palmar (or true) opposition of the pollex, which is unprecedented for pterosaurs and represents a sophisticated adaptation related to arboreal locomotion. Principal-coordinate analyses suggest an arboreal lifestyle for the new species but not for other closely related species from the same locality, implying a possible case of ecological niche partitioning. The discovery adds to the known array of pterosaur adaptations and the history of arborealism in vertebrates. It also adds to the impressive early bloom of arboreal communities in the Jurassic of China, shedding light on the history of forest environments."

IIRC you showed interest in several of these themes earlier. It's a detailed research paper, open access.
The critter has been named *Kunpengopterus.* The genus has been known since 2010, but this paper
is about a new species, *K. antipollicatus*. [As you will immediately recognize, this refers to the true opposability of the "thumb".


Hope you like it. I in turn will read the paper you dug up as time allows:

> African pterosaur
> -likely spent time flying above open-water environments and diving to feed, like gannets and brown pelicans do today," Jacobs said. "Epapatelo otyikokolo was not a small animal, and its wingspan was approximately 4.8 m, or nearly 16 feet."
>
> But fossils discovered since the study suggest that some of the newly identified pterosaur species could have been even larger creatures, Polcyn said. Pterosaurs were impressive creatures, with some of the largest species having wingspans of nearly 35 feet.
>
> https://www.sciencedaily.com/releases/2022/11/221109151941.htm
>

> The genus name 'Epapatelo' is the translation of the word from the Angolan Nhaneca dialect meaning "wing," and the species name "otyikokolo" is the translation of 'lizard.' The Nhaneca or Nyaneka people are an Indigenous group from Angola's Namibe Province, the region where the fossils were found.

[Daud Deden]

Really amazing how much can be found out about these animals and their ecologies. The reversed thumbs show that grasping fully evolved, allowing not just compressional perching but tensional perching in forest canopy's stiff lateral winds. In hominoids, slow brachiation required long strong opposed thumbs, while fast brachiation did not, as hook-like hands predominate where fast swinging is advantageous, as in gibbons & spider monkeys.