Scute lifted

[Anyfoot]

This is not my tortoise, it's a ladies who rescues redfoots here in the uk. One of the entire scutes lifted.
Looks to me as if damage was done to the bone when very young.
Anyway the purpose of the thread was to see if we can learn anything from the photos. I can ask for more photos if required.
@Markw84 @Tom

 

[JoesMum]

Possibly burn damage from a hot lamp being too close at sometime?

Or a strimmer?

Unusual to see an entire plate go.

 

[Tidgy's Dad]

When my Tidgy was a baby girl, someone decided one of her little yellow scutes would make a nice pendant. So they cut it out with a Stanley knife. When I took her it was open, yellow and oozing, cut down to he lung lining.I bathed it many times a day and nursed her back to health.
Here you can see the yellow 'scab' that finally formed over the wound.

It's the most yellow one third right at the top.
Eventually, after a couple more years, it dropped off to reveal rough, black, new growth underneath.

Third from the right with no yellow bits.

 

[Anyfoot]

That's sad Adam. Has keratin grown back or has the bone discoloured?

 

[Markw84]

Craig

I assume you are asking in reference to learnings about pyramiding, not the cause of the damage.

First - the keratin will grow back eventually over the bone. That can take some time, though.

It is also easy to see where the bone plates are and how they do not match the scute seams. As I had mentioned before, in reference to how resistant vertebral scutes are to reverse pyramiding once started, it is a good example of how the scute seam on the vertebrals has actually "folded" the vertebral bone directly below and has tipped the adjacent bone. Since there are so many more vertebral bones than scutes, you see there is an entire bone plate that is tipped between adjacent bone plates that are "folded". Since all growth comes from the bone seams, that new growth is now coming in at an angle, irrespective of how much pressure at the new scute seam has been eliminated due to better humidity. The tipped bone plate continues to grow at that angle. That does not happen with the costals with scute plates only covering two adjacent bone plates (and fontanelles when young).

 

[Tidgy's Dad]

That's sad Adam. Has keratin grown back or has the bone discoloured?

The keratin has grown back.
And the story had a happy ending.
Tidgy is alive and well and is a spoiled brat.

 

[Anyfoot]

Craig

I assume you are asking in reference to learnings about pyramiding, not the cause of the damage.

First - the keratin will grow back eventually over the bone. That can take some time, though.

It is also easy to see where the bone plates are and how they do not match the scute seams. As I had mentioned before, in reference to how resistant vertebral scutes are to reverse pyramiding once started, it is a good example of how the scute seam on the vertebrals has actually "folded" the vertebral bone directly below and has tipped the adjacent bone. Since there are so many more vertebral bones than scutes, you see there is an entire bone plate that is tipped between adjacent bone plates that are "folded". Since all growth comes from the bone seams, that new growth is now coming in at an angle, irrespective of how much pressure at the new scute seam has been eliminated due to better humidity. The tipped bone plate continues to grow at that angle. That does not happen with the costals with scute plates only covering two adjacent bone plates (and fontanelles when young).

Yes learn more about how bone and keratin grows.
You've lost me a bit Mark. I'll have to re-read this later when I'm not influenced by rum and coke. I'm in Lanzarote at the moment.
I bet even you haven't built one of these in your yard.
View attachment 221371

Craig

I assume you are asking in reference to learnings about pyramiding, not the cause of the damage.

First - the keratin will grow back eventually over the bone. That can take some time, though.

It is also easy to see where the bone plates are and how they do not match the scute seams. As I had mentioned before, in reference to how resistant vertebral scutes are to reverse pyramiding once started, it is a good example of how the scute seam on the vertebrals has actually "folded" the vertebral bone directly below and has tipped the adjacent bone. Since there are so many more vertebral bones than scutes, you see there is an entire bone plate that is tipped between adjacent bone plates that are "folded". Since all growth comes from the bone seams, that new growth is now coming in at an angle, irrespective of how much pressure at the new scute seam has been eliminated due to better humidity. The tipped bone plate continues to grow at that angle. That does not happen with the costals with scute plates only covering two adjacent bone plates (and fontanelles when young).

hi mark. I'm not ignoring you, I'm on holiday and I have to think about your posts before answering. I'm not convinced I'm fully understanding you. You can see this scute was covering between 6 and 9 bone plate joints.
Are you saying that once the scute exceeds the bone joint it then has no influence on that bone plates growth direction because the edge of the scute is now over the adjacent bone plate. So we can only ever hope to correct the new bone plate that the edge of the scute is over.

When a tort hatches is there only one bone plate per vertebral scute and more bone plates are added as growth commences?

 

[Markw84]

Yes learn more about how bone and keratin grows.
You've lost me a bit Mark. I'll have to re-read this later when I'm not influenced by rum and coke. I'm in Lanzarote at the moment.
I bet even you haven't built one of these in your yard.
View attachment 221371

hi mark. I'm not ignoring you, I'm on holiday and I have to think about your posts before answering. I'm not convinced I'm fully understanding you. You can see this scute was covering between 6 and 9 bone plate joints.
Are you saying that once the scute exceeds the bone joint it then has no influence on that bone plates growth direction because the edge of the scute is now over the adjacent bone plate. So we can only ever hope to correct the new bone plate that the edge of the scute is over.

When a tort hatches is there only one bone plate per vertebral scute and more bone plates are added as growth commences?

Enjoy your holiday, Craig! Reply if you want whenever it works for you, but I'll respond now to help your question. Your attachement would not download, So I couldn't see it.

I see my answer above is a bit confusing and I misstated about a bone plate between the folded scutes. I should have wrote the seam between the folded scutes.

The vertebrals (bones) in a tortoise are the vertebrals of the spine fused into plates. There are more vertebral bones than vertebral scutes. Scute seams never sit directly on top of bone sutures (seams) but are staggered. This gives the tortoise shell much more strength. The number is set and does not change. There are more bone plates than scutes, so some bones lay totally under a scute, while others straddle a seam above. With vertebrals, there are the bones corresponding to vertebrae plus the top ends of what would correspond to ribs under each vertebral scute. So lots of growth sutures under one vertebral scute. As it lays out, on a front to back line corresponding to the "spine" - there is a bone centered under each scute and one in the middle of the scute. Every other vertebrae has a scute seam in the middle. With a pyramiding tortoise, the bone straddling the seam is being forced to bend downward in the middle, folding into a "V". Since the vertebrae don't extend to the sides of the scute, the entire bone is folded to a "V" shape laterally. The in-between vertebrae correspondingly bends to a reverse shape folding upwards in the middle. This leaves the entire suture separating the two vertebrae tipped uniformly along its entire length. As growth is happening at the sutures - all the new growth is happening at that plane created by this tipping. Relieving the pressure of new keratin growth cannot change the tipped angle as easily that has already been created. So bone growth continues to push outward at that angle. With costals, the sutures of the "ribs" also cross from the costal scutes to the vertebral scutes. So there is no single suture that is deformed to a single angle. Plus the fontanels of a tortoise it's first several years create no set angle as a suture has not yet developed there. SO... we see most tortoises will be much more resistant to changing the pyramiding pattern with their vertebral scutes as opposed to their costals which can often almost completely straighten out with straight growth as soon as humid conditions are provided. My stars who came to me pyramided are an excellent example of that.

I know it is hard to explain and I'm sure follow by written word alone. When you get back and are bored enough to go through this, if interested - let me know and I can also show pictures of my stars and diagrams of bone suture vs scute seam layouts.

 

[Anyfoot]

Cheers mark. I'll re-read again tomorrow. But I think I'm following you now.
Got to go enjoy myself.
The attachment was a pool bar. Don't know why it didn't load and for some reason the photo didn't save to my phone.

 

[Anyfoot]

Enjoy your holiday, Craig! Reply if you want whenever it works for you, but I'll respond now to help your question. Your attachement would not download, So I couldn't see it.

I see my answer above is a bit confusing and I misstated about a bone plate between the folded scutes. I should have wrote the seam between the folded scutes.

The vertebrals (bones) in a tortoise are the vertebrals of the spine fused into plates. There are more vertebral bones than vertebral scutes. Scute seams never sit directly on top of bone sutures (seams) but are staggered. This gives the tortoise shell much more strength. The number is set and does not change. There are more bone plates than scutes, so some bones lay totally under a scute, while others straddle a seam above. With vertebrals, there are the bones corresponding to vertebrae plus the top ends of what would correspond to ribs under each vertebral scute. So lots of growth sutures under one vertebral scute. As it lays out, on a front to back line corresponding to the "spine" - there is a bone centered under each scute and one in the middle of the scute. Every other vertebrae has a scute seam in the middle. With a pyramiding tortoise, the bone straddling the seam is being forced to bend downward in the middle, folding into a "V". Since the vertebrae don't extend to the sides of the scute, the entire bone is folded to a "V" shape laterally. The in-between vertebrae correspondingly bends to a reverse shape folding upwards in the middle. This leaves the entire suture separating the two vertebrae tipped uniformly along its entire length. As growth is happening at the sutures - all the new growth is happening at that plane created by this tipping. Relieving the pressure of new keratin growth cannot change the tipped angle as easily that has already been created. So bone growth continues to push outward at that angle. With costals, the sutures of the "ribs" also cross from the costal scutes to the vertebral scutes. So there is no single suture that is deformed to a single angle. Plus the fontanels of a tortoise it's first several years create no set angle as a suture has not yet developed there. SO... we see most tortoises will be much more resistant to changing the pyramiding pattern with their vertebral scutes as opposed to their costals which can often almost completely straighten out with straight growth as soon as humid conditions are provided. My stars who came to me pyramided are an excellent example of that.

I know it is hard to explain and I'm sure follow by written word alone. When you get back and are bored enough to go through this, if interested - let me know and I can also show pictures of my stars and diagrams of bone suture vs scute seam layouts.

Mark.
Ok think I'm with you now, and it's how I imagined it, and BTW it's not boring.

What I'm trying to understand as I'm reading what you put is the bone growth from hatchling to adult.
How much of the bone structure is actually developed in a neonate, where are the fontanelles and how do they fill in as the tortoise grows, are there any fontanelles on the verterbral plates?
Are we 100% sure that the scutes and bone sutures grow at the same ratio throughout the growth periods. So are the vertebral scutes seams always over the centre of a bone plate. Is there ever a point when the scute seam passes over a suture during growth.

I nearly deleted the last paragraph because as I was writing I had the thought of..... we never see the tipping point actually on a suture which means all the bone plates,sutures and scutes have to grow at the same ratio from a neonate. Even as a neonate the areola(scute) must cover the same amount of sutures as when it's an adult.
This cancels out one of my past thoughts that growing a tort too fast can get the scute seem to push a suture down. It's just not possible, we are always pushing the centre of a bone plate down during the soft supple stage, once set it's hard to come off that point it was tipped too during the supple stage.

Is that correct Mark.


Now onto the coastals
Back to coastals,we know we have fontanelles to contend with during growth. When the fontanelles fill in are they smoothing out the scutes or is the filling process just following where the scutes already are?

Think I've shown you this before Mark. But I'm loading it again, this baby is around 2.5" SCL. I don't know how old a 2.5" Greek is but this photo shows fontanelles and how sutures are always crossing over scutes at a fixed ratio to growth. What it doesn't tell us is how developed the vertebral bone plates are in a neonate.

 

[Anyfoot]

Will the tortoise with the lifted scute re-grow keratin over the bone? If yes, how?

 

[Markw84]

Craig

Vertebral bones are fully formed by the time a tortoise hatches. they are certainly more pliable and will add mass and thicken, but there are no fontanels, but sutures between bones. From the last picture you posted, you can clearly see how there is always a full vertebral bone in the middle of each vertebral scute. Natures design makes this a stronger structure, but it also lends itself towards more extreme pyramiding along the vertebrals. All the suture around the vertebral are fully formed at hatching and any pyramiding will create a tipping of these sutures. As all growth is generated at the bone sutures, this growth is then at that angle - both vertebral to vertebral and vertebral to pleural. since the areolae of each scute is fixed above a specific bone location, that relationship of the areolae alone never changes throughout growth.

As you go down the pleural in a young tortoise, the sutures are not formed and the fontanels are quite wide. It seems it takes 3-5 years for the sutures to complete all the way down to the peripherals. I do not see this bone, as it grows, smoothing out any pyramiding that is happening in the costal scutes. But since there is no full bone structure that has been deformed there, when conditions are correct, the new growth will come in smooth.

Yes, new keratin does re-grow over damaged/exposed bone. New bone develops beneath the dead bone along with a layer of keratin. The old bone eventually flakes off revealing the new growth beneath. I have not had any experience with this if regards to pyramiding and any effect it would have as most cases I have seen are older tortoises.

 

[Anyfoot]

Sorry Mark but again.

Are you saying the tipping point of the bone that creates pyramiding always starts from sutures? If so this means that a hatchings areola seams have to be directly above sutures in order for the scute Seams to be able to tip bone at sutures. This doesn't make sense because between two adjacent vertebrals there are always 2 sutures.

 

[Anyfoot]

Mark.

I'm going to attempt to explain what I'm thinking with the help of 2 sketches. Vertebral Scutes are highlighted in green and the squiggly lines represent bone sutures.

For the vertebral scute seams to be able to tip bone at a suture then a hatching has to start out life with a different suture configuration. See Fig1. Trouble is with this is the suture marked X would have to grow out creating 2 sutures either side of the 2 vertebral scutes. It's not possible.
So this means the suture configuration is same throughout growth relative to scute seam positions. (Everything just gets bigger). See Fig2. If everything just grows bigger and stops in position relative to each other then scute seams never cross bone sutures in parallel, they do at 90deg(for example vertebral scute seams that meet coastal scute seams cross pleural sutures(circled on fig2)). If scute seams never cross sutures in parallel then how can the bone be tipped at a suture? Surely bone is tipped from the scute seam(new keratin growth) which is never on a suture.



I know I'm dwelling on this suture and seam thing a bit Mark, But I need to make sure I'm understanding it correctly, it's important I understand this because I THINK it proves growth rate is irrelevant.

 

[theguy67]

Question regarding the tortoise above:

If the bone is dead, and the opening is significant, will keratin and new bone still grow? What if the bone was missing, does size of the opening determine if it can close up? I had a female a few years ago with a dead section of shell. I was told to leave it. One rainy fall, water got between the scutes and bone causing it to rot all the way through. Long story short, bone and keratin decayed leaving a 4x3 inch hole in a 9 inch long tortoise. I've heard some say if the hole is too large, it won't close up.

 

[Markw84]

Craig

Your second drawing is correct.

Each scute is "attached" to a point of the underlying bone ONLY at the areolae. I have approximated that with a red filled circle. That is the only part that remains in a fixed position. The rest "floats" over a thin layer of living tissue between the bone and scute. Growth occurs at the bone sutures. This seperates the scutes that then lay down new keratin, espanding the scute and fills in that gap. In a pyramiding tortoise, that gap, as it fills in, grows more downward creating pressure on the underlying bone in that position. As you can then see in your diagram that I added arrows to, the way vertebrals are spaced, there is a bone suture growing half way between the areolae and scute edge on each vertebral scute. With downward pressure at the scute seams you drew in green, that will then tip the bone so all those sutures where I placed arrows are growing on a new plane.

 

[Markw84]

Question regarding the tortoise above:

If the bone is dead, and the opening is significant, will keratin and new bone still grow? What if the bone was missing, does size of the opening determine if it can close up? I had a female a few years ago with a dead section of shell. I was told to leave it. One rainy fall, water got between the scutes and bone causing it to rot all the way through. Long story short, bone and keratin decayed leaving a 4x3 inch hole in a 9 inch long tortoise. I've heard some say if the hole is too large, it won't close up.

I don't know the specific answer to your question. Tortoises are amazingly resilient and I've seen many with devastating injuries recover and live long lives. @Yvonne G posted a picture of a tortoise with a good portion of the shell burned. Even though it was a good portion of the shell, it did eventually break away revealing new bone and keratin beneath.

It is a different story if the injury was THROUGH the bone and exposed the tortoises inside tissue as opposed to old bone being exposed as in the above photo.

 

[theguy67]

I don't know the specific answer to your question. Tortoises are amazingly resilient and I've seen many with devastating injuries recover and live long lives. @Yvonne G posted a picture of a tortoise with a good portion of the shell burned. Even though it was a good portion of the shell, it did eventually break away revealing new bone and keratin beneath.

It is a different story if the injury was THROUGH the bone and exposed the tortoises inside tissue as opposed to old bone being exposed as in the above photo.

Yes, it was certainly a site. Picked her up one day and felt my finger go through the decaying bone. 3 scutes.

Sorry for hijacking @Anyfoot, tortoise shells are both fascinating and mysterious.

 

[Anyfoot]

Craig

Your second drawing is correct.

Each scute is "attached" to a point of the underlying bone ONLY at the areolae. I have approximated that with a red filled circle. That is the only part that remains in a fixed position. The rest "floats" over a thin layer of living tissue between the bone and scute. Growth occurs at the bone sutures. This seperates the scutes that then lay down new keratin, espanding the scute and fills in that gap. In a pyramiding tortoise, that gap, as it fills in, grows more downward creating pressure on the underlying bone in that position. As you can then see in your diagram that I added arrows to, the way vertebrals are spaced, there is a bone suture growing half way between the areolae and scute edge on each vertebral scute. With downward pressure at the scute seams you drew in green, that will then tip the bone so all those sutures where I placed arrows are growing on a new plane.

View attachment 222199

Right Mark. I now understand what you are saying. Even though the scute seam is beyond the suture under the areola in a neonate, the scute seam acts with leverage on the supple suture causing it to tip the suture.

 

[Anyfoot]

Yes, it was certainly a site. Picked her up one day and felt my finger go through the decaying bone. 3 scutes.

Sorry for hijacking @Anyfoot, tortoise shells are both fascinating and mysterious.

Any tort talk is good talk