From Wikipedia, the free encyclopedia

Copy-and-paste of discussion of image from English Wikipedia article talk page

The following text has been copied and pasted here from the talk page of the English Wikipedia article on Nyasasaurus for the benefit of those wishing to understand the review process that the image went through and the changes made in accordance with suggestions from editors knowledgeable in the area of dinosaur morphology. At the time this talk page was created there were no other freely licensed images of this animal, and so a composite creature made up of basic circular/ oval shapes was generated to give readers the chance to "see" something of what the animal might have looked like, at least in terms of its proportions and posture.

Section: Which six vertebrae?

Can anyone tell me which six vertebrae are the ones referenced in the article? I have done a basic illustration of the animal for Wikipedia and have placed the described bones in the middle of the back but they could just as easily be tail bones or neck bones. I would like to place them correctly in the drawing, and none of the links I am finding seems to say where they are located in the body. The humerus does not connect directly to the spine anywhere, but my guess is that these verts are close to it (i.e., upper back). Ideas? KDS4444 Talk 06:14, 11 December 2012 (UTC)

There's a nice (and active) dinosaur image review at Wikipedia:WikiProject Dinosaurs/Image review. The editors there very often already have access to the papers in question (or soon will have, I think, in the case of Nyasasaurus). Firsfron of Ronchester 06:18, 11 December 2012 (UTC)
A very nice illustration! But, as you already feared, the vertebrae are at least partly not in the correct position. Three of them are sacrals and thus should be placed as a series of three in the hip. The other three are "posterior pre-sacrals", thus dorsals. Also it should be noted that you seem to have been influenced too much by a general derived theropod Gestalt. Although these elements have not be found, the more likely situation would be that there were five fingers and five toes, not three! Furthermore, in the left leg these toes are too long and the penultimate phalanges would not curve upwards. A last point of attention might be that the humerus has an enormous deltopectoral crest: its upper part should bulge out to the front a lot. A difficult issue is whether you also should include the elements of the second specimen which would add three neck vertebrae — the two posterior dorsal might be seen as overlapping.-- MWAK ( talk) 09:15, 11 December 2012 (UTC)
That answers almost all of my questions as well as a few I never even made and for which I am grateful. I have now made all of the suggested changes, but am sticking on a few points: the second set of three vertebrae— should they also be placed in a series or are they non-articulating? Also, you call them "pre-sacral thus dorsal": does this mean they are more or less in what in humans would be the lumbar region? Or are they further forwards/ up? (or further backwards/ down??). Next, you mention the second set of discovered vertebrae which would add three more to my drawing and make the two posterior dorsal as overlapping— does this mean that these "neck" vertebrae occur along the dorsum (are maybe thoracic)? Please clarify if you can. My familiarity with primate morphology is much greater than my familiarity with that of other animals, to say nothing of reptiles, to say nothing at all of archosaurs, but they all have vertebrae— I just need a little more coaching and it will be done. Thank you! KDS4444 Talk 06:42, 12 December 2012 (UTC)
I'll try to answer your questions. The three presacral vertebrae have not been found in an articulated series. They are also very fragmentary, which makes it very difficult to determine their position. The authors do not express very definite opinions on this but personally I think one of the vertebrae, having a ventral keel, is rather anterior and that the other two are not contiguous to it. Perhaps the best way to reflect this in a diagram would be to place one of them in the front of the dorsum and the other two evenly spaced behind it. The cervical vertebrae of the referred specimen consist of an isolated element and an articulated series of two with the anterior of these missing the front part. They are all indicated as "anterior cervicals" in the paper. Personally I think these may well be number four, five and six. They might be indicated by a series of three placed from the upper bend of the neck downwards. They are also rather elongated, three times longer than tall. I hope this helps.-- MWAK ( talk) 09:09, 12 December 2012 (UTC)
If I have understood everything you have said, then what you see now should be an accurate revision of my original drawing, including revised placement of vertebrae (all nine), size of humerus, size of feet, angles of toes, number of toes, and number of fingers, plus some 3D shading to top it all off. Please tell me I did all of this correctly (!). Also, please tell me if I did not. Would like to get it right. Image is now being used on the Spanish and Russian Wikipedias as well. KDS4444 Talk 13:20, 13 December 2012 (UTC)
I think you did an excellent job within the constraints that are inherent to your intention: to break down the animal body into simple shapes. As regards the general proportions, there still is a minor point: the hand in all basal dinosaurs we know of approaches or even surpasses the lower arm in length. So the manual digits (assuming they represent both fingers and metacarpals) should be about 60% longer.-- MWAK ( talk) 21:34, 13 December 2012 (UTC)
Consider it done. Ah, if time were no object... But I will spend another few moments on this, and then we shall let Nyassasaur run free in its imaginary-conceptual form, at least. Perhaps it can be the basis for some future individual to use as a springboard for a more complete rendition of such a thus-far incompletely known creature. You are most welcome. KDS4444 Talk 22:12, 13 December 2012 (UTC)
Thank you for your efforts! As you say, the species is very incompletely known and any detailed interpretation would be quite speculative, especially since its phylogenetic position is so uncertain. You seem to have found an elegant solution to this problem.-- MWAK ( talk) 07:29, 14 December 2012 (UTC)
I would like to echo MWAK's praise for your work here. -- Khajidha ( talk) 20:47, 14 December 2012 (UTC)
Thank you both! It is good to know that one's work is appreciated. KDS4444 Talk 06:42, 15 December 2012 (UTC)

KDS4444 Talk 23:36, 1 January 2013 (UTC) reply

From Wikipedia, the free encyclopedia

Copy-and-paste of discussion of image from English Wikipedia article talk page

The following text has been copied and pasted here from the talk page of the English Wikipedia article on Nyasasaurus for the benefit of those wishing to understand the review process that the image went through and the changes made in accordance with suggestions from editors knowledgeable in the area of dinosaur morphology. At the time this talk page was created there were no other freely licensed images of this animal, and so a composite creature made up of basic circular/ oval shapes was generated to give readers the chance to "see" something of what the animal might have looked like, at least in terms of its proportions and posture.

Section: Which six vertebrae?

Can anyone tell me which six vertebrae are the ones referenced in the article? I have done a basic illustration of the animal for Wikipedia and have placed the described bones in the middle of the back but they could just as easily be tail bones or neck bones. I would like to place them correctly in the drawing, and none of the links I am finding seems to say where they are located in the body. The humerus does not connect directly to the spine anywhere, but my guess is that these verts are close to it (i.e., upper back). Ideas? KDS4444 Talk 06:14, 11 December 2012 (UTC)

There's a nice (and active) dinosaur image review at Wikipedia:WikiProject Dinosaurs/Image review. The editors there very often already have access to the papers in question (or soon will have, I think, in the case of Nyasasaurus). Firsfron of Ronchester 06:18, 11 December 2012 (UTC)
A very nice illustration! But, as you already feared, the vertebrae are at least partly not in the correct position. Three of them are sacrals and thus should be placed as a series of three in the hip. The other three are "posterior pre-sacrals", thus dorsals. Also it should be noted that you seem to have been influenced too much by a general derived theropod Gestalt. Although these elements have not be found, the more likely situation would be that there were five fingers and five toes, not three! Furthermore, in the left leg these toes are too long and the penultimate phalanges would not curve upwards. A last point of attention might be that the humerus has an enormous deltopectoral crest: its upper part should bulge out to the front a lot. A difficult issue is whether you also should include the elements of the second specimen which would add three neck vertebrae — the two posterior dorsal might be seen as overlapping.-- MWAK ( talk) 09:15, 11 December 2012 (UTC)
That answers almost all of my questions as well as a few I never even made and for which I am grateful. I have now made all of the suggested changes, but am sticking on a few points: the second set of three vertebrae— should they also be placed in a series or are they non-articulating? Also, you call them "pre-sacral thus dorsal": does this mean they are more or less in what in humans would be the lumbar region? Or are they further forwards/ up? (or further backwards/ down??). Next, you mention the second set of discovered vertebrae which would add three more to my drawing and make the two posterior dorsal as overlapping— does this mean that these "neck" vertebrae occur along the dorsum (are maybe thoracic)? Please clarify if you can. My familiarity with primate morphology is much greater than my familiarity with that of other animals, to say nothing of reptiles, to say nothing at all of archosaurs, but they all have vertebrae— I just need a little more coaching and it will be done. Thank you! KDS4444 Talk 06:42, 12 December 2012 (UTC)
I'll try to answer your questions. The three presacral vertebrae have not been found in an articulated series. They are also very fragmentary, which makes it very difficult to determine their position. The authors do not express very definite opinions on this but personally I think one of the vertebrae, having a ventral keel, is rather anterior and that the other two are not contiguous to it. Perhaps the best way to reflect this in a diagram would be to place one of them in the front of the dorsum and the other two evenly spaced behind it. The cervical vertebrae of the referred specimen consist of an isolated element and an articulated series of two with the anterior of these missing the front part. They are all indicated as "anterior cervicals" in the paper. Personally I think these may well be number four, five and six. They might be indicated by a series of three placed from the upper bend of the neck downwards. They are also rather elongated, three times longer than tall. I hope this helps.-- MWAK ( talk) 09:09, 12 December 2012 (UTC)
If I have understood everything you have said, then what you see now should be an accurate revision of my original drawing, including revised placement of vertebrae (all nine), size of humerus, size of feet, angles of toes, number of toes, and number of fingers, plus some 3D shading to top it all off. Please tell me I did all of this correctly (!). Also, please tell me if I did not. Would like to get it right. Image is now being used on the Spanish and Russian Wikipedias as well. KDS4444 Talk 13:20, 13 December 2012 (UTC)
I think you did an excellent job within the constraints that are inherent to your intention: to break down the animal body into simple shapes. As regards the general proportions, there still is a minor point: the hand in all basal dinosaurs we know of approaches or even surpasses the lower arm in length. So the manual digits (assuming they represent both fingers and metacarpals) should be about 60% longer.-- MWAK ( talk) 21:34, 13 December 2012 (UTC)
Consider it done. Ah, if time were no object... But I will spend another few moments on this, and then we shall let Nyassasaur run free in its imaginary-conceptual form, at least. Perhaps it can be the basis for some future individual to use as a springboard for a more complete rendition of such a thus-far incompletely known creature. You are most welcome. KDS4444 Talk 22:12, 13 December 2012 (UTC)
Thank you for your efforts! As you say, the species is very incompletely known and any detailed interpretation would be quite speculative, especially since its phylogenetic position is so uncertain. You seem to have found an elegant solution to this problem.-- MWAK ( talk) 07:29, 14 December 2012 (UTC)
I would like to echo MWAK's praise for your work here. -- Khajidha ( talk) 20:47, 14 December 2012 (UTC)
Thank you both! It is good to know that one's work is appreciated. KDS4444 Talk 06:42, 15 December 2012 (UTC)

KDS4444 Talk 23:36, 1 January 2013 (UTC) reply


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