Comment on Koolasuchus and girl rework by dewlap
Just so long as you dont give them glandular frog skin, because that would make no sense.
I wasn't intentionally going for the granular frog skin (don't think there is any granules on my drawing...) but I was trying to have the skin for the Koolasuchus like the giant salamanders (kind of leathery). So basically what you are saying is that it is pretty much no change but adding some scutes... (although I'm not sure how big or the shape of them) I'll just have to wait and see if there are more materials (such as scutes) turn up before I make any changes...
I meant *glandular* as in slimy, with pores.
I made the suggestion because a recent illustration of Koolahsuchus by Peter Trusler gave it a full coat of reptillian scales. I saw this as logical given that similar amphibians gave rise to reptiles. But a leathery skin is equally logical, as some reptiles such as turtles are scaleless with leathery skin.
I made the suggestion because a recent illustration of Koolahsuchus by Peter Trusler gave it a full coat of reptillian scales. I saw this as logical given that similar amphibians gave rise to reptiles. But a leathery skin is equally logical, as some reptiles such as turtles are scaleless with leathery skin.
Ah... my bad (I've misread your post). Then again I didn't make it slimy, it was "just" out of water so it is kind of glossy (that was my intention, I'm sorry that you didn't see it that way...) just to indicate to the viewers that they are at least semi-aquatic and amphibian-like. You have reading into too much of my drawing, it wasn't suppose to be representing sliminess of the skin...
To be honest, I do doubt that they have a full coat of reptilian scales, the best that they would have developed are fish-like dermal scales (which are not homologous structures to the reptilian scales).
When you said "well known" (...that these animals had a covering of scales...) from your original message I thought you must have some kind of direct evidence to back your claim, however, on your last post you stated that you are basing this from a picture and your interpretation of this picture. Sorry from my ignorance and I'm sorry but only a picture (from your last post) doesn't make it a "well known" fact. It is just a theory.
This actually reminds me of the "biplane microraptor", I won't get into the details but basically you have one group of scientists saying that they (microraptors) sprayed their legs because it is more flight efficient and "logical", on the other hand you have another group of scientists saying that it would be structurally (hip socket and femur head joint) impossible for the microraptors to achieve such pose. I've seen some of the leg spraying illustrations of microraptor... so does it make it a irrefutable "well known" fact that they sprayed their legs during flight (because it is logical) or even have the ability to spread their legs to the side? It is a theory... yes but has it been proven as well known (proven fact), the answer is NO...
BTW when I said leathery skin, I was talking about perhaps something equivalent to some tree frog skin which has a waterproof layer (perhaps developed from keratin, similar to the keratin that you found on their hands and feet).
To be honest, I do doubt that they have a full coat of reptilian scales, the best that they would have developed are fish-like dermal scales (which are not homologous structures to the reptilian scales).
When you said "well known" (...that these animals had a covering of scales...) from your original message I thought you must have some kind of direct evidence to back your claim, however, on your last post you stated that you are basing this from a picture and your interpretation of this picture. Sorry from my ignorance and I'm sorry but only a picture (from your last post) doesn't make it a "well known" fact. It is just a theory.
This actually reminds me of the "biplane microraptor", I won't get into the details but basically you have one group of scientists saying that they (microraptors) sprayed their legs because it is more flight efficient and "logical", on the other hand you have another group of scientists saying that it would be structurally (hip socket and femur head joint) impossible for the microraptors to achieve such pose. I've seen some of the leg spraying illustrations of microraptor... so does it make it a irrefutable "well known" fact that they sprayed their legs during flight (because it is logical) or even have the ability to spread their legs to the side? It is a theory... yes but has it been proven as well known (proven fact), the answer is NO...
BTW when I said leathery skin, I was talking about perhaps something equivalent to some tree frog skin which has a waterproof layer (perhaps developed from keratin, similar to the keratin that you found on their hands and feet).
Truthfully, I came to my personal conclusion that they had a covering of scales well before I had seen that image, so I didnt base it on that.
It is my personal opinion, that if they had scutes and armor, which are basically a derivative of scales, then they would have had scales to start with.
It is my personal opinion, that if they had scutes and armor, which are basically a derivative of scales, then they would have had scales to start with.
I don't have problem with your conclusion but please read your original message. You are basically implying it is a FACT (...I object to this style of labyrinthodont portrayal. It is well known that these animals had a covering of scales...) since this is a scientific topic so I would assume that there was studies or some kind of proof that these scales were present. What you have sent me on your second message both links and reference are sound but inconclusive to say that they do definitely have body scales.
[NOTE: the "scales" of fish and amphibian-grade tetrapods and the "scales" of reptiles are not homologous structures by any means! The former are dermal elements, which in many early fish groups contained dentine and enamel (although many derived actinopterygian groups, and convergently the amphibian-grade tetrapods, lost dentine and enamel in their scales and instead had simply keratinous structures. The scales of reptiles are epidermal keratinous structures. It is the gastralia (belly ribs) of amniotes which are the direct homologues of the dermal scales of fish and amphibian-grade tetrapods (although it may be that osteoderms (bony armor) of tetrapods represent a deep homology with these structures).] [link]
Of course I don't mind that you have your opinion but to imply that it is a irrefutable fact (or as you say "Well Known" again referring to your original message) ... I don't know...
[NOTE: the "scales" of fish and amphibian-grade tetrapods and the "scales" of reptiles are not homologous structures by any means! The former are dermal elements, which in many early fish groups contained dentine and enamel (although many derived actinopterygian groups, and convergently the amphibian-grade tetrapods, lost dentine and enamel in their scales and instead had simply keratinous structures. The scales of reptiles are epidermal keratinous structures. It is the gastralia (belly ribs) of amniotes which are the direct homologues of the dermal scales of fish and amphibian-grade tetrapods (although it may be that osteoderms (bony armor) of tetrapods represent a deep homology with these structures).] [link]
Of course I don't mind that you have your opinion but to imply that it is a irrefutable fact (or as you say "Well Known" again referring to your original message) ... I don't know...
I'm sorry, I simply assumed that scutes would indicate scales, which is why I was so assertive. Sorry :/
That's alright never mind.
Just a short note in regard to the scutes that you might be referring to...
...that there is no reason to assume that the dermal armour of some of the early tetrapods would have prevented cutaneous gas exchange, although the large size of many of these animals would have resulted in a less than favourable surface area to volume ratio for cutaneous gas exchange...[link]
Just a short note in regard to the scutes that you might be referring to...
...that there is no reason to assume that the dermal armour of some of the early tetrapods would have prevented cutaneous gas exchange, although the large size of many of these animals would have resulted in a less than favourable surface area to volume ratio for cutaneous gas exchange...[link]
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In addition, while it is true that reptilian scales have to derive from its ancestor (likely the order Anthracosauria). However, Koolasuchus was a member of the order Temnospondyli (and probably relates to the modern amphibians) which means that it is not "necessary" for Koolasuchus to have any kind of scales/proto-scales. Maybe the Labyrinthodontia group has scale coverings early in their evolution before it splits into different orders like Ichthyostegalia, Anthracosauria, Temnospondyli and Lepospondyli. At this time, all I can say is it's not definite.
The bottom line is that to say something is well known (to me it means definite, absolute or the norm), there shouldn't be any uncertainties (...But a leathery skin is equally logical, as some reptiles such as turtles are scaleless with leathery skin...) but if you also think that is a possibility then how can you say your conclusion is well known... of course what you are saying is a possibility and I never doubt that. All I'm saying is that I can't agree on the absolute quantitation (well known) of your original statement which isn't based on irrefutable proofs.
The bottom line is that to say something is well known (to me it means definite, absolute or the norm), there shouldn't be any uncertainties (...But a leathery skin is equally logical, as some reptiles such as turtles are scaleless with leathery skin...) but if you also think that is a possibility then how can you say your conclusion is well known... of course what you are saying is a possibility and I never doubt that. All I'm saying is that I can't agree on the absolute quantitation (well known) of your original statement which isn't based on irrefutable proofs.