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Pyramiding – Solving the Mystery

Markw84

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I've never seen anything written on wild baby or juvenile sulcatas. Where are you getting this info? I wanna read it too!!!
back in the mid 80's and early 90's I made friends with a guy from Africa who did import some various things. He agreed to try to get some tortoises for me. His contacts did end up getting me a few Leopards but the process took a long time. I asked him to get me any info he could about where they came from, the habitat, etc. We tried to get some sulcatas the early 90's when I first started seeing some. Because of shipping, I was wanting smaller, yet well started juveniles and wanted smooth, wild caught back then. All the sources he spoke with told him small was very hard to find. Most were larger that were pulled from burrows, and never got small ones that way. A few mentioned rarely finding yearlings and when they did, it was several at a time all in the same location, and they learned to dig around when the found one as others would be nearby. Never did get any from these sources, but did end up with a nice adult pair from Niger.

All this was anecdotal, and not verified. Very interesting to me. But when I first read THE CRYING TORTOISE, I was struck with some of his comments about juveniles:

From Chapter 6-1 -
"The young tortoises benefit from the first rains, and especially from the fast growing plants on which they feed and take water in abundance. Also, the young can bury themselves more easily, thus avoiding certain predators..."

Later in same chapter -

"Conditions in the wild vary from year to year, and animals can suffer from unexpected droughts, serious fires, a reduced vegetal carpet, etc. A new-born tortoise weighing 50 g will reach 200 g after four months. and I kg by the end of the year. When two years old it might weigh 3 kg. and 6 kg after three years. It is at this age that the young tortoise will dig an individual burrow. thus escaping from most predators."

From Chapter 6-4 -
"The juveniles hide, often in small groups, under leaves or in natural hollows. They only excavate in autumn, often together, forming recesses that are enlarged holes, rather than real burrows. "

That's a few of the quotes I could quickly find that go towards this conversation.
 

DeanS

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I once saw a 4 incher going to town, and also a 6 incher one time, but those are both one time only very unusual cases. Normally, the actual burrowing doesn't start until they are about 10-12" like Mark noted.


I don't think the burrow is intentionally used as a pyramiding preventative by wild sulcatas. I think pyramiding prevention is a side effect of burrow usage, and burrow usage is simply a way to avoid above ground temperature extremes as you noted.
I think this little guy takes the cake! Somewhere between 4 and 5 inches...and eight months old!
IMG_4326.JPG IMG_4333.JPG IMG_4353.JPG IMG_4382.JPG
 

Gijoux

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Great info.
My challenge, that hopefully you can explain, is this. One, do you think this pertains to every species, as some seem to always pyramid. Two, how is it some tortoises, being raised in very high humidity, can still pyramid, while its tank mate does not?
The reason I question this, I have raised one leopard from being laid, incubation, to now. High humidity the whole time and still some pyramiding.
I now have four babies hatched October, again high humidity and slight pyramiding showing.
Their substrate is never dry, the humidity never below 80 at tort height, usually higher.
Because I do have to feed during winter months more grocery greens and mazuri then warmer months, I did figure it was probably a faster growth, as mazuri does seem to add growth fairly quick. However, I have not fed the four hatchlings any mazuri yet.
I believe "stress" is handled differently by different species as well as individuals. Stress hormones affect "Mineralocorticoid" production by the Adrenal glands, which has an overall effect on fluid retention (Kidney) and bone/keratin production since the Kidney plays a major role in Vitamin D2 to D3 conversion and ultimately bone growth. D3 is the active form used by the body. The Adrenal hormones plays a major role in Thyroid production and activation of T4 into T3, which also plays a role in Bone and Keratin production as well as growth and activity. In humans we can tell a lot about overall health, especially Adrenal/Thyroid issues, by looking at fingernail growth. I have observed horses, whose hooves (bones covered by Keratin/Lamina) are failing and falling apart (Laminitis), when given thyroid hormone, have major improvement. I believe exercise to improve blood flow/circulation is also an important feature to all aspects of health. Perhaps a species or individual that is more fearful or shy will be more likely to be affected negatively through adrenal imbalance which affects fluid and mineral content in the body.


Quick comment... I thought (and read recently) when it is really hot or during drought periods or brumation, there is very little bodily excretions happening, in fact for long periods of time, nothing. So, unlike well-kept fed and watered torts that probably go often, those out in the wilds don’t quite go that often enough to maintain humidity levels deep inside a burrow.

Just throwing that info into the discussion.
Deep inside a burrow will be cooler in the Summer and warmer in Winter. By not excreting fluid and waste they are keeping the moisture within their bodies.
 

Anyfoot

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I believe "stress" is handled differently by different species as well as individuals. Stress hormones affect "Mineralocorticoid" production by the Adrenal glands, which has an overall effect on fluid retention (Kidney) and bone/keratin production since the Kidney plays a major role in Vitamin D2 to D3 conversion and ultimately bone growth. D3 is the active form used by the body. The Adrenal hormones plays a major role in Thyroid production and activation of T4 into T3, which also plays a role in Bone and Keratin production as well as growth and activity. In humans we can tell a lot about overall health, especially Adrenal/Thyroid issues, by looking at fingernail growth. I have observed horses, whose hooves (bones covered by Keratin/Lamina) are failing and falling apart (Laminitis), when given thyroid hormone, have major improvement. I believe exercise to improve blood flow/circulation is also an important feature to all aspects of health. Perhaps a species or individual that is more fearful or shy will be more likely to be affected negatively through adrenal imbalance which affects fluid and mineral content in the body.
Nice post.

Not sure I’m understanding this last sentence correctly.
What you are saying is an active tortoise has the adrenaline running and therefore a balance of fluid and mineral circulation with the higher blood flow. Wouldn’t a tortoise that is more fearful through anxiety of predators be showing high adrenaline too?
 

Gijoux

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Nice post.

Not sure I’m understanding this last sentence correctly.
What you are saying is an active tortoise has the adrenaline running and therefore a balance of fluid and mineral circulation with the higher blood flow. Wouldn’t a tortoise that is more fearful through anxiety of predators be showing high adrenaline too?
Absolutely! But having the ability to move around freely, finding safe cover as well as the ability to graze, would actually lower Cortisol (associated with Adrenaline). Being trapped in a small area without the ability to hide (predators or not), will cause stress and all the physiologic changes. Exercise increases blood circulation which delivers oxygen, fluids and nutrients to the organs, as well as lowering Cortisol, the "Fight or Flight" hormone.
 

Ketta

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True! rhinos and pigs oh and buffalos take mud baths to keep their skin hydratated..
 

Ketta

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True! rhinos and pigs oh and buffalos take mud baths to keep their skin hydratated..
 

Ketta

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True! rhinos and pigs oh and buffalos take mud baths to keep their skin hydratated.. I read that hatchlings stay hidden for 2-3 weeks until their sac yolk is fully consumed.
 

Anyfoot

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True! rhinos and pigs oh and buffalos take mud baths to keep their skin hydratated.. I read that hatchlings stay hidden for 2-3 weeks until their sac yolk is fully consumed.
You can pretty much do what you want with a redfoot and they grow smooth for first 4 to 6 months. Then things change.
I’ve had only 2 that it was obvious they were going to pyramid within a month or two of hatching. All others have been smooth up until around 5 months old. I’ve tried every diet and soaking method on the planet.
 

Anyfoot

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@Markw84

Hi Mark. We’ve not spoke for a while. My life is demanding at the moment:rolleyes:.

A while back we were talking about how torts can still pyramid later in life. I’m not convinced. I think there is a point where as long as the bone is strong and healthy the keratin can not dictate the bone growth direction.
Have a look at this tort. I’ve purposely not cleaned her so you can see how dry they get. Even though I spray my tort house down with a hose pipe a few times a wk, and have a 3sqft pond that evaporates and a water fall. They drink at will. I don’t soak them anymore apart from when I wash them.
This one is about 6yrs old now. She’s about 7” SCL. Her siblings are 10”+ now. For some reason she just didn’t grow much at all for a couple yrs. Over the last yr she seems to be growing quickly all of a sudden. Gaining approx 1”SCL in the last yr. look at her newest growth rings(last 3 rings) You can see how perfect the new growth is. It’s growing in a perfectly horizontal plane, no pyramiding wafts so ever. But yet I have 6 months olds that start to pyramid. Living in the exact same tort house but in a tortoise table, and being soaked daily and sprayed.
Once the bone is set and strong enough something drastic has to happen to tip the bone to a different angle.

You can see the latest white growth line. Something I didn’t see on this tort for a couple years. Don’t know why and tbh I’d accepted she has stunted growth, the extra scute made me suspicious of something abnormal too.

So in a nutshell. She’s having a very fast growth spurt in dryish conditions but growing smooth.

Your thoughts as usual. Or anyone’s.

DCCB939C-6346-45D1-BF45-81496E5391D4.jpeg 4F7FEF58-A79A-42CD-B6DA-818A6859D48A.jpeg 288D537E-3777-4156-AFA6-B0ED47EE7C1D.jpeg 85FF3ACE-7A6F-4FA7-8DFB-B55F8F16FC4C.jpeg 3ED47287-40EA-4B6B-B12A-A8E04B11BB3C.jpeg 960C4440-BCD1-46E5-8CA6-5BFEF8758507.jpeg
 

Toddrickfl1

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@Markw84

Hi Mark. We’ve not spoke for a while. My life is demanding at the moment:rolleyes:.

A while back we were talking about how torts can still pyramid later in life. I’m not convinced. I think there is a point where as long as the bone is strong and healthy the keratin can not dictate the bone growth direction.
Have a look at this tort. I’ve purposely not cleaned her so you can see how dry they get. Even though I spray my tort house down with a hose pipe a few times a wk, and have a 3sqft pond that evaporates and a water fall. They drink at will. I don’t soak them anymore apart from when I wash them.
This one is about 6yrs old now. She’s about 7” SCL. Her siblings are 10”+ now. For some reason she just didn’t grow much at all for a couple yrs. Over the last yr she seems to be growing quickly all of a sudden. Gaining approx 1”SCL in the last yr. look at her newest growth rings(last 3 rings) You can see how perfect the new growth is. It’s growing in a perfectly horizontal plane, no pyramiding wafts so ever. But yet I have 6 months olds that start to pyramid. Living in the exact same tort house but in a tortoise table, and being soaked daily and sprayed.
Once the bone is set and strong enough something drastic has to happen to tip the bone to a different angle.

You can see the latest white growth line. Something I didn’t see on this tort for a couple years. Don’t know why and tbh I’d accepted she has stunted growth, the extra scute made me suspicious of something abnormal too.

So in a nutshell. She’s having a very fast growth spurt in dryish conditions but growing smooth.

Your thoughts as usual. Or anyone’s.

View attachment 272252 View attachment 272253 View attachment 272254 View attachment 272255 View attachment 272256 View attachment 272257
@Anyfoot I'm right at the five month mark (140g) with my hatchling and growth seems good, what you think?IMG_20190515_183116904.jpg IMG_20190515_183104289.jpg IMG_20190515_183049345.jpg
 

Fester

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I remember as a young boy one of the things that fueled my interest with chelonians was seeing how much was just NOT KNOWN about them. When I became fascinated with an animal, I ran to the encyclopedia to find out about it. I also always went to the library and checked out every book I could find on the subject. What is the best diet? Temperature? How about incubating eggs when I got them? Nowhere could I find anything about what temperature was best. So I had to figure things out myself. Today we are so lucky with information at our fingertips. The internet – this forum! Yet still today, when it comes to chelonians, so much still seems to no be KNOWN. Most everything is, at best, debated. Some proposing one way, while another ‘expert’ says that won’t work. But we do have a chance now to see literally thousands of examples of results. But even results can be misleading if we don’t take into consideration the unique conditions that keeper in that part of the world provided. So little seems to be KNOWN!

Pyramiding is one of the best examples. In todays world of modern technology and scientific knowledge, there is still no proposed theory anywhere on how, metabolically, pyramiding even happens. It was just the last decade that it even became more apparent how to even prevent it. But that is still hotly debated. Most import of wild caught tortoises has been stopped for some time now. Pyramided tortoise has become the norm. Most pictures and artwork depicting tortoise show pyramided tortoise as “normal”!

We have enough evidence now to see that humidity is the key to preventing it. I can now grow smooth tortoises at will, after over 40 years of never being able to. I tried side by side groups of low protein vs higher protein groups. Groups of Fast growth vs slow growth. 3 groups of Store bough greens vs commercial pellets, vs natural grazing only. Stable temperatures vs night drops. Everything all the ‘experts’ said, I tried. Then I heard about humidity. I found this forum and read Tom’s thread on ending pyramiding. It all made sense immediately. I think it was the frustration of failing so many times and having to try so many proposed solutions that allowed me to find all the things that did not affect pyramiding. So many who have not had to struggle with it because of their location do not have that perspective. They will say it is diet, exercise, slower growth, etc, etc. All necessary for the most healthy of tortoises, but I found had nothing to do with pyramiding.

So, once I found out how to keep tortoises from pyramiding, the question still remained – why? Why did humidity work? Why didn’t diet or fast growth or exercise matter? I needed to know why! And no one, nowhere, knew why. There were enough pieces to the puzzle that were known. I had watched tortoise grow for decades. I monitored how pyramiding started and progressed. I could see what was happening. But to put the remaining pieces together took me into research in the anatomy and physiology of tortoise, keratin growth, bone growth, and even orthodontics.

A tortoise is a very uniquely modified animal. It is a vertebrate, yet carries its main skeletal structure on the outside. To protect this outside, exposed bone, another protective layer of keratin has developed over the bone. This is a unique adaptation as two hard surfaces normally do not come immediately in contact with each other in vertebrates. Bones are surrounded by cartilage and muscle - and even in more exposed areas, layers of hair and skin that cushion and provide ample blood flow. Keratin is also an interesting substance. Forming hair, nails, feathers, horns, it normally grows where the new keratin being formed is protected by living tissue from drying too quickly. Cuticles, hair follicles, feather sheaths, scalp around the base of horns, etc, etc. The tortoise, however, grows keratin that is exposed immediately to the external environment as it starts to spread and grow. No protective covering on the outside growth areas.

If you watch a tortoise grow and pyramid, you soon see that pyramiding is driven by the scutes, not by bone. For maximum strength, the scutes of a tortoise never align with the seams of an underlying bone. They all overlap - creating a very strong structure. Yet when a tortoise pyramids, the pyramiding ALWAYS follows the pattern of the scute. Where individual bones lay has no effect on the pattern of pyramiding. The scute remains a uniform thickness. It does not thicken in the center. The bone also retains a fairly uniform thickness, but deforms to match to shape of the pyramiding. Bone would not grow that way unless something was forcing it to deform. I also saw that pyramiding was the forming of valleys at the seams of scutes, not the raising of the centers. A perfectly smooth tortoise will have the higher, more domed look that matches the peaks of a pyramided tortoise, not the valleys.

From studies on keratin, we see that keratin is quite hydroscopic when new and forming. It is more pliable and absorbs water easily. As it matures, and “dries” it becomes much harder and stiffer and loses most of its hydroscopic properties and no longer absorbs water and swells. It becomes a much stiffer and stronger, protective substance. Tortoises add very little thickness to a scute as it grows. New keratin is formed at the seams of the spreading scutes as a tortoise grows. As the underlying bone grows, the seam spreads between the scutes. Keratin spreads outward to fill this seam and slowly adds thickness, swelling to match the “finished” thickness of the scute. Often, this new keratin will swell thicker than the older scute section and create a ridge in a faster growing “smooth” tortoise. This will dry and age over the next several months and smooth out to a more flush level, but leave a distinct ‘growth ring’. The thickness of the scute of a 30” sulcata is pretty much the same as a 15” sulcata. New keratin is not added to the underside of the central parts of scutes as a tortoise grows.

They have no protective layer over the new keratin growth, so the outside of the newly forming keratin is exposed to the environment. If while this new keratin is growing and spreading, it is exposed to conditions that allow it to dry too quickly, it will lose its ability to continue to swell and fill in thickness. The underside of the keratin, in direct contact to living tissue (the epithelial layer) still is pliable and swelling. This imbalance forces the new growth to swell downward as it cannot continue to fill in upward. This puts a small but constant pressure on that epithelial layer and puts it in compression as it is being pressed into the bone below. This is the beginning of pyramiding.

How does this slight pressure deform bone? As mentioned earlier, the tortoise shell is very uncommon in vertebrates in having bone next to a hard surface. There is a very thin layer of tissue that separated the bone from the scutes called the epithelial layer. This delivers blood supply and nutrients to the bone and new keratin growth and creates a barrier between the bone and the hard scute. Epithelial tissues are everywhere in a vertebrate. It covers the outside of your body (skin), lines organs, vessels, and cavities. But it also is defined by not covering a hard surface and in direct contact with bone. However, there is one place I found something most similar to this positioning of hard surfaces. Teeth and the jaw bone. There is a layer formed between the teeth and the jawbone that separates and somewhat cushions the jawbone from the teeth. It is called the periodontal ligament. It still retains pockets of epithelial cells throughout that effects some of its functions. AND, it was In studying examples of how bone can be deformed or reshaped, I again was lead to teeth.

When a slight but consistent pressure is applied to a tooth, it puts the periodontal ligament into compression on one side of the tooth in the direction of the pressure. That triggers the formation of an important type of cell in our bodies called osteoclasts. Osteoclasts are specialized cells that break down and dissolve bone. Bones are constantly restructuring and rebuilding. Another type cell, the osteoblast – builds new bone. This adds density to our bones and grows our bones when we are younger. Under stress, (exercise) it is triggered to build density and more strength. Osteoclasts, on the other hand, are called into play to remove older bone, and also to tap into the stores of calcium and phosphorus in our bones in times where our levels of calcium or phosphorus in our blood drops too low. Our bones are more than an inert structural item. They are living, constantly remodeling stores of tissue and minerals.

So how do they move teeth? Apply a slight but constant pressure on a tooth. That puts the periodontal ligament in compression on one side of the tooth. That triggers the formation of a bunch of extra osteoclasts that form at that site of the pressure and start dissolving bone to relieve that pressure. On the other side of the tooth, the periodontal ligament is then in tension. This triggers osteoblasts that are called into action and an abundance of osteoblasts go to work forming new bone to fill in the area that is putting the periodontal ligament in tension. So - the bone is not deformed. It is broken down and removed on one side and new bone is built on the other side.

In our tortoises, when the new keratin dries to quickly, it is putting that epithelial layer into compression as the new keratin growth can only swell and fill in downward. The epithelial layer call osteoclasts into action at the site to dissolve and remove bone and relieve the compression on that epithelial layer. This creates a groove in the bone directly under the new growth. Even in smooth, “normal growth” tortoises, you can often see grooves in the bone formed by the growth rings. However, if the dry conditions persist and the tortoise continues to grow in conditions that are too dry, the newly forming seam will also press down on the epithelial layer over the bone and deepen the groove forming into a valley. If this continues, the actual plane of the bone is changed to the pyramided shape. Bone does not grow from the seams, but instead grows from wide areas throughout the bone. So the tipped areas themselves (particularly along the vertebrals with more bones than scutes) will be growing bone in a direction that will simply add to the pyramiding. That will make it much harder to alter the pyramiding in a tortoise once it has progressed substantially. Yet a young tortoise, with just the start of pyramiding, can develop quite smooth future growth easily at an earlier stage that hasn’t progressed too far.

So - for me this answered all the questions. All the pieces fit and all the scenarios I actually see, anywhere, all fit. There are two things needed to pyramid a tortoise. Active growth and dry conditions. It is only by putting the epithelial layer into compression that osteoclasts will be formed to dissolve bone under the area in compression.

Diet will not matter. Pressure triggers osteoclast genesis. With poor diet you can have a tortoise with pyramiding PLUS metabolic bone disease. If anything, the pyramiding is releasing a bit more calcium into the bloodstream to help bone growth elsewhere! If diet is so poor that growth is stopped, of course there would be no pyramiding because there is no growth of new keratin.

Excess protein will not trigger osteoclast genesis. And certainly not only in specific areas under scute seams. Excess protein will create excess purines and possible stone formation problems. Smooth or pyramided!

Exercise does trigger osteoblasts genesis and better bone growth and density. It does not trigger osteoclast genesis and again would have no effect on localizing that under scute seams.

Fast growth does not affect pyramiding. You can have fast growing smooth tortoises and fast growing pyramided tortoises. Just as you can have slow growing smooth tortoises or slow growing pyramided tortoises. If they grow, fast or slow, when conditions are too dry – they will pyramid.

UVB exposure will not change pyramiding. It will certainly affect calcium uptake and utilization as D3 is necessary for that. So it will affect bone growth, but will not trigger bone dissolving in such a specific, localized area as only under the scute seams. In extreme cases, it will lead to metabolic bone disease as osteoclasts are triggered throughout the greater storage rich bone areas as it looks to release calcium back in to the blood stream. But that is also more concentrated in the hip and pelvic bones and plastral bones. Not at all calling osteoclasts into play under scute seams. Totally separate metabolic events.

Tortoises have ended up in the wild in “left over” habitats. They have been outcompeted and predated upon in any of the more favorable habitats. Their survival is because the have found way to survive in habitats that are much more hostile. Water is the key ingredient to survival. They are masters at maintaining it and finding microclimates that are less harsh. Nature gives them food and growth along with the moisture. In drier times, the food disappears, and the tortoise aestivates or brumates and does not grow. Their first few years, most tortoises spend their lives buried in the ground, or in leaf litter, always protecting themselves not only from predation, but from desiccation.

In so many areas their ‘natural range’ has been altered by man. With the advent of irrigation and reservoirs, the expansion of agriculture into their native ranges has even changed the food availability to drier times of the year and we see pyramided “wild” tortoises. Or so many now kept in compounds and fed through drier times and kept from digging and burrowing naturally – it is hard to tell what a “natural” tortoise looks like. We would have to look back 1000 years or so in many areas to really see a true wild tortoise in totally unchanged habitat. Certainly, in captivity, we have changed the way they live and the way they look.

Perhaps we are now learning enough to finally learn the conditions in which these amazing animals will do best. I am seeing more and more examples of tortoises that I believe look the way they were designed to grow. Maybe that will soon become the norm. Hopefully in the not too distant future we will see smooth tortoises again represented in the pictures and artwork depicting their species.
Absolutely amazing ❤ Thank you for such a thorough and wonderful explanation that everyone should read/heed!!!
 

Fester

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A few thoughts...

I think it would help. would it be enough?? Don't know but probably not! - depending upon the lighting/heating/hides provided.

We are talking about NEW keratin, not fully formed keratin. The hydroscopic properties of the keratin changes dramatically as it matures. Your fingernails are mature keratin. The new keratin is beneath the cuticles and protected! That is part of the issue I saw in my original quandaries. Most all keratin structure in nature develop protected, except tortoises. Hair follicles beneath the skin, fingernails by cuticle, feathers by a protective sheath, horns forming beneath the skin before emerging, etc, etc. All richly hydrated by surrounding tissue and blood supply as it forms and then hardens. But once a tortoise hatches, the new keratin forming as the shell grows is directly exposed to the environment. New keratin needs moisture and needs to stay hydrated long enough, in that new stage - allowing it to swell and develop its thickness before hardening and becoming more resistant. Young tortoises hide and stay buried in mud, puddles, wet dirt, roots of plants, etc. - not just to hide from predators, but to keep in an environment to allow this growth. They can't just go from egg to the harsh environment. There needs a transitional stage. That's what drives me crazy when people talk about emulating the climate from which they "naturally come". They themselves are expert at avoiding that climate!!

Absolutely a balance. My guess is that a young growing tortoise spends very little time actually basking. They thrive and grow in times of the year where ground temps and daily temps are high enough for maintaining proper metabolic body temps. I bet their UV exposure is indirect mostly. Cryptic basking in partial shade edges. Learning how to balance hydration and lighting/basking/proper artificial heat is key.
This, too, adds to your original explantation; well said. This should be written for media such as ReptileMagazine for more exposure.
 

eminart

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I remember as a young boy one of the things that fueled my interest with chelonians was seeing how much was just NOT KNOWN about them. When I became fascinated with an animal, I ran to the encyclopedia to find out about it. I also always went to the library and checked out every book I could find on the subject. What is the best diet? Temperature? How about incubating eggs when I got them? Nowhere could I find anything about what temperature was best. So I had to figure things out myself. Today we are so lucky with information at our fingertips. The internet – this forum! Yet still today, when it comes to chelonians, so much still seems to no be KNOWN. Most everything is, at best, debated. Some proposing one way, while another ‘expert’ says that won’t work. But we do have a chance now to see literally thousands of examples of results. But even results can be misleading if we don’t take into consideration the unique conditions that keeper in that part of the world provided. So little seems to be KNOWN!

Pyramiding is one of the best examples. In todays world of modern technology and scientific knowledge, there is still no proposed theory anywhere on how, metabolically, pyramiding even happens. It was just the last decade that it even became more apparent how to even prevent it. But that is still hotly debated. Most import of wild caught tortoises has been stopped for some time now. Pyramided tortoise has become the norm. Most pictures and artwork depicting tortoise show pyramided tortoise as “normal”!

We have enough evidence now to see that humidity is the key to preventing it. I can now grow smooth tortoises at will, after over 40 years of never being able to. I tried side by side groups of low protein vs higher protein groups. Groups of Fast growth vs slow growth. 3 groups of Store bough greens vs commercial pellets, vs natural grazing only. Stable temperatures vs night drops. Everything all the ‘experts’ said, I tried. Then I heard about humidity. I found this forum and read Tom’s thread on ending pyramiding. It all made sense immediately. I think it was the frustration of failing so many times and having to try so many proposed solutions that allowed me to find all the things that did not affect pyramiding. So many who have not had to struggle with it because of their location do not have that perspective. They will say it is diet, exercise, slower growth, etc, etc. All necessary for the most healthy of tortoises, but I found had nothing to do with pyramiding.

So, once I found out how to keep tortoises from pyramiding, the question still remained – why? Why did humidity work? Why didn’t diet or fast growth or exercise matter? I needed to know why! And no one, nowhere, knew why. There were enough pieces to the puzzle that were known. I had watched tortoise grow for decades. I monitored how pyramiding started and progressed. I could see what was happening. But to put the remaining pieces together took me into research in the anatomy and physiology of tortoise, keratin growth, bone growth, and even orthodontics.

A tortoise is a very uniquely modified animal. It is a vertebrate, yet carries its main skeletal structure on the outside. To protect this outside, exposed bone, another protective layer of keratin has developed over the bone. This is a unique adaptation as two hard surfaces normally do not come immediately in contact with each other in vertebrates. Bones are surrounded by cartilage and muscle - and even in more exposed areas, layers of hair and skin that cushion and provide ample blood flow. Keratin is also an interesting substance. Forming hair, nails, feathers, horns, it normally grows where the new keratin being formed is protected by living tissue from drying too quickly. Cuticles, hair follicles, feather sheaths, scalp around the base of horns, etc, etc. The tortoise, however, grows keratin that is exposed immediately to the external environment as it starts to spread and grow. No protective covering on the outside growth areas.

If you watch a tortoise grow and pyramid, you soon see that pyramiding is driven by the scutes, not by bone. For maximum strength, the scutes of a tortoise never align with the seams of an underlying bone. They all overlap - creating a very strong structure. Yet when a tortoise pyramids, the pyramiding ALWAYS follows the pattern of the scute. Where individual bones lay has no effect on the pattern of pyramiding. The scute remains a uniform thickness. It does not thicken in the center. The bone also retains a fairly uniform thickness, but deforms to match to shape of the pyramiding. Bone would not grow that way unless something was forcing it to deform. I also saw that pyramiding was the forming of valleys at the seams of scutes, not the raising of the centers. A perfectly smooth tortoise will have the higher, more domed look that matches the peaks of a pyramided tortoise, not the valleys.

From studies on keratin, we see that keratin is quite hydroscopic when new and forming. It is more pliable and absorbs water easily. As it matures, and “dries” it becomes much harder and stiffer and loses most of its hydroscopic properties and no longer absorbs water and swells. It becomes a much stiffer and stronger, protective substance. Tortoises add very little thickness to a scute as it grows. New keratin is formed at the seams of the spreading scutes as a tortoise grows. As the underlying bone grows, the seam spreads between the scutes. Keratin spreads outward to fill this seam and slowly adds thickness, swelling to match the “finished” thickness of the scute. Often, this new keratin will swell thicker than the older scute section and create a ridge in a faster growing “smooth” tortoise. This will dry and age over the next several months and smooth out to a more flush level, but leave a distinct ‘growth ring’. The thickness of the scute of a 30” sulcata is pretty much the same as a 15” sulcata. New keratin is not added to the underside of the central parts of scutes as a tortoise grows.

They have no protective layer over the new keratin growth, so the outside of the newly forming keratin is exposed to the environment. If while this new keratin is growing and spreading, it is exposed to conditions that allow it to dry too quickly, it will lose its ability to continue to swell and fill in thickness. The underside of the keratin, in direct contact to living tissue (the epithelial layer) still is pliable and swelling. This imbalance forces the new growth to swell downward as it cannot continue to fill in upward. This puts a small but constant pressure on that epithelial layer and puts it in compression as it is being pressed into the bone below. This is the beginning of pyramiding.

How does this slight pressure deform bone? As mentioned earlier, the tortoise shell is very uncommon in vertebrates in having bone next to a hard surface. There is a very thin layer of tissue that separated the bone from the scutes called the epithelial layer. This delivers blood supply and nutrients to the bone and new keratin growth and creates a barrier between the bone and the hard scute. Epithelial tissues are everywhere in a vertebrate. It covers the outside of your body (skin), lines organs, vessels, and cavities. But it also is defined by not covering a hard surface and in direct contact with bone. However, there is one place I found something most similar to this positioning of hard surfaces. Teeth and the jaw bone. There is a layer formed between the teeth and the jawbone that separates and somewhat cushions the jawbone from the teeth. It is called the periodontal ligament. It still retains pockets of epithelial cells throughout that effects some of its functions. AND, it was In studying examples of how bone can be deformed or reshaped, I again was lead to teeth.

When a slight but consistent pressure is applied to a tooth, it puts the periodontal ligament into compression on one side of the tooth in the direction of the pressure. That triggers the formation of an important type of cell in our bodies called osteoclasts. Osteoclasts are specialized cells that break down and dissolve bone. Bones are constantly restructuring and rebuilding. Another type cell, the osteoblast – builds new bone. This adds density to our bones and grows our bones when we are younger. Under stress, (exercise) it is triggered to build density and more strength. Osteoclasts, on the other hand, are called into play to remove older bone, and also to tap into the stores of calcium and phosphorus in our bones in times where our levels of calcium or phosphorus in our blood drops too low. Our bones are more than an inert structural item. They are living, constantly remodeling stores of tissue and minerals.

So how do they move teeth? Apply a slight but constant pressure on a tooth. That puts the periodontal ligament in compression on one side of the tooth. That triggers the formation of a bunch of extra osteoclasts that form at that site of the pressure and start dissolving bone to relieve that pressure. On the other side of the tooth, the periodontal ligament is then in tension. This triggers osteoblasts that are called into action and an abundance of osteoblasts go to work forming new bone to fill in the area that is putting the periodontal ligament in tension. So - the bone is not deformed. It is broken down and removed on one side and new bone is built on the other side.

In our tortoises, when the new keratin dries to quickly, it is putting that epithelial layer into compression as the new keratin growth can only swell and fill in downward. The epithelial layer call osteoclasts into action at the site to dissolve and remove bone and relieve the compression on that epithelial layer. This creates a groove in the bone directly under the new growth. Even in smooth, “normal growth” tortoises, you can often see grooves in the bone formed by the growth rings. However, if the dry conditions persist and the tortoise continues to grow in conditions that are too dry, the newly forming seam will also press down on the epithelial layer over the bone and deepen the groove forming into a valley. If this continues, the actual plane of the bone is changed to the pyramided shape. Bone does not grow from the seams, but instead grows from wide areas throughout the bone. So the tipped areas themselves (particularly along the vertebrals with more bones than scutes) will be growing bone in a direction that will simply add to the pyramiding. That will make it much harder to alter the pyramiding in a tortoise once it has progressed substantially. Yet a young tortoise, with just the start of pyramiding, can develop quite smooth future growth easily at an earlier stage that hasn’t progressed too far.

So - for me this answered all the questions. All the pieces fit and all the scenarios I actually see, anywhere, all fit. There are two things needed to pyramid a tortoise. Active growth and dry conditions. It is only by putting the epithelial layer into compression that osteoclasts will be formed to dissolve bone under the area in compression.

Diet will not matter. Pressure triggers osteoclast genesis. With poor diet you can have a tortoise with pyramiding PLUS metabolic bone disease. If anything, the pyramiding is releasing a bit more calcium into the bloodstream to help bone growth elsewhere! If diet is so poor that growth is stopped, of course there would be no pyramiding because there is no growth of new keratin.

Excess protein will not trigger osteoclast genesis. And certainly not only in specific areas under scute seams. Excess protein will create excess purines and possible stone formation problems. Smooth or pyramided!

Exercise does trigger osteoblasts genesis and better bone growth and density. It does not trigger osteoclast genesis and again would have no effect on localizing that under scute seams.

Fast growth does not affect pyramiding. You can have fast growing smooth tortoises and fast growing pyramided tortoises. Just as you can have slow growing smooth tortoises or slow growing pyramided tortoises. If they grow, fast or slow, when conditions are too dry – they will pyramid.

UVB exposure will not change pyramiding. It will certainly affect calcium uptake and utilization as D3 is necessary for that. So it will affect bone growth, but will not trigger bone dissolving in such a specific, localized area as only under the scute seams. In extreme cases, it will lead to metabolic bone disease as osteoclasts are triggered throughout the greater storage rich bone areas as it looks to release calcium back in to the blood stream. But that is also more concentrated in the hip and pelvic bones and plastral bones. Not at all calling osteoclasts into play under scute seams. Totally separate metabolic events.

Tortoises have ended up in the wild in “left over” habitats. They have been outcompeted and predated upon in any of the more favorable habitats. Their survival is because the have found way to survive in habitats that are much more hostile. Water is the key ingredient to survival. They are masters at maintaining it and finding microclimates that are less harsh. Nature gives them food and growth along with the moisture. In drier times, the food disappears, and the tortoise aestivates or brumates and does not grow. Their first few years, most tortoises spend their lives buried in the ground, or in leaf litter, always protecting themselves not only from predation, but from desiccation.

In so many areas their ‘natural range’ has been altered by man. With the advent of irrigation and reservoirs, the expansion of agriculture into their native ranges has even changed the food availability to drier times of the year and we see pyramided “wild” tortoises. Or so many now kept in compounds and fed through drier times and kept from digging and burrowing naturally – it is hard to tell what a “natural” tortoise looks like. We would have to look back 1000 years or so in many areas to really see a true wild tortoise in totally unchanged habitat. Certainly, in captivity, we have changed the way they live and the way they look.

Perhaps we are now learning enough to finally learn the conditions in which these amazing animals will do best. I am seeing more and more examples of tortoises that I believe look the way they were designed to grow. Maybe that will soon become the norm. Hopefully in the not too distant future we will see smooth tortoises again represented in the pictures and artwork depicting their species.

Excellent read. I'm just re-entering the tortoise husbandry research world. A lot has changed since I got my Egyptian tortoise 13 years ago. In retrospect, I wish I'd continued to read and stay on top of the latest ideas during the past few years. She has some moderate pyramiding that maybe I could have prevented.

Your ideas make sense, and with the apparent success that people are having with the more humid approach, I'm inclined to believe the riddle is solved. I'm definitely going to go with the enclosed approach for my new leopard tortoise.

I wonder if the same results could be achieved by recreating the tortoises' natural habitats, complete with micro climates. But, feasibly, this would be much more difficult to maintain on a captive-sized scale. We don't always know exactly what a tortoise may need, and don't have the space to create every option. That can lead to an animal spending most of its time in a space that's a little too dry because that is the only hiding spot that meets his temp needs, or vice versa. So, I do think this "new" idea of keeping the entire enclosure at what we're guessing is the optimal humidity is probably the best way to go.

Anyway, thanks for the write-up. This, along with Tom's post about humid enclosures makes sense. I'm glad I ventured back over here and found them. I thought I had a decent understanding of how to keep my new tortoise, but I think you guys over here have advanced tortoise husbandry quite a bit since I learned about tortoise tables 15 years ago.
 
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