Dimetrodon and Other Pelycosaurs May Have Lacked Sails

[Halichoeres]

The lateral struts might not have supported a sail, but I don't think they would necessarily have to. I can imagine an herbivore that doesn't move very fast but has a sail for thermoregulation or for display or for whatever. In most cases if it does have a sail, the associated tissue would need to be highly vascular, and therefore vulnerable to damage. The small struts could be enough to minimize damage done to the sail in the event of a conflict. I don't know much about early synapsids so I don't know if there's any support for a function like that, but I don't think it's special pleading to suggest that such a function for secondary struts is plausible.

[Plasticbeast95]

That's exactly what I mean, looking at those branch-lets I can't see how they would have supported a sail.

Eddy's sail (if it existed) was most likely thicker than Dimetrodon's. how else do you explain the spinelets?

also, who are the girls in your sig? Ive seen them all over the place.

[stargatedalek]

They would the Futami's from iDOLM@STER, I've been meaning to get a new sig more suited to the forum but I've yet to get around to making one

I guess that makes sense, pelycosaurs aren't something I know an awful lot about so its nice to get some discussion. Is there anything to suggest a possible inflating (frigate bird like) display structure? Perhaps that could have been another possible function of the branch-lets.

[Plasticbeast95]

They would the Futami's from iDOLM@STER, I've been meaning to get a new sig more suited to the forum but I've yet to get around to making one

I guess that makes sense, pelycosaurs aren't something I know an awful lot about so its nice to get some discussion. Is there anything to suggest a possible inflating (frigate bird like) display structure? Perhaps that could have been another possible function of the branch-lets.

ok, I just didn't know, ive seen them all over the place and didn't know who they were.

the main issue with an inflatasail is how you could rig the respiratory system to get air to the sail.

[Dinoguy2]

That's exactly what I mean, looking at those branch-lets I can't see how they would have supported a sail.

Funnily enough, Cope thought those cross bars each supported a series of lateral sails. That's why he called them sails in the first place, instead of ridges or crests or something. He thought those cross bars were much longer in life and they literally helped the animal sail along the water. Picture a living pirate ship!

Some artists later misunderstood what he said, thinking it also applied to Dimetrodon, causing them to call Dimetrodon's crest a "sail" too and showing it getting blown "sideways" along the water, which is ridiculous.

I agree though that based on this study, those cross bars probably supported a thick collagen layer and the whole "sail" was more of a thick ridge like Acrocanthosaurus with no spines visible in life.

[Derek.McManus]

Werid...that illustration looks like something from the natural history of Skull Island

[SpartanSquat]

Sorry to be late at the party...but I think we should take thing with caution. From what I read the study of Dimetrodon was made in 2012. And not new the last year. I highly recommend you read this blog post about Dimetrodon and parents.
http://palaeos-blog.blogspot.com.es/2015/08/tiene-el-dimetrodon-una-nueva-imagen.html
If you could translate it I highly recommend you to read it. For what I read, the study used patologic specimen. And one specie not all the 12 Dimetrodon species. And think one question: If its related with mammals, why expose the spines? Its very risky considering an animal that could battle with other Dimetrodons.

[MLMjp]

Good that I´m Spanish.

Thanks for the link Roland.

Misinterpretation guys. Just what happens every time in the world of paleontology and prehistoric knowledge. Things like this makes my hobby very confusing a lot of times.....

Also, this means that I can still purchase a Dimetrodon figure, since I don't have one

[stargatedalek]

It's certainly true that this doesn't apply to every species of Dimetrodon, but I'm still putting my money on the paper where it applies.

[Mamasaurus]

Perhaps I'm misunderstanding what I've read, but it seems that the healed fractures in the spines would indicate that at least some form of soft tissue was covering them. The fact that specimens with intact spines, yet with multiple healed fractures, makes me think that exposed spines are very unlikely. Wouldn't they just snap off?  If anything, I would think that a thicker ridge like acrocanthosaurus is more likely. The fragile bones could break, but not a lot of serious, lasting damage because all that tissue was holding it together. 

If the environment was very hot, then a fleshy ridge would function a lot like a jackrabbit's ears in the desert. Hot blood circulates through the tall, fleshy ridge, which gets exposed to any breeze available (and sheds heat if there is no breeze). Either way, the blood cools down, which keeps the animal from overheating. 

I'm not a scientist, but it seems more plausible to have a thicker layer of flesh over such delicate spines, rather than a thin membrane that is easily torn, or exposed bone that is easily snapped off.