Fossil find reveals just how big carnivorous dinosaur may have grown

[sauroid]

Abelisaurid theropods may have had feathers. first time ive read anything about that.
http://www3.imperial.ac.uk/newsandeventspggrp/imperialcollege/newssummary/news_29-2-2016-9-34-57

[DinoLord]

Interesting story; thanks for sharing. I guess this one was about Carnotaurus-sized. But I don't think the specimen provides any specific evidence for feathers. Presumably the feathers are just speculation based on their prevalence in other dinosaur groups.

[SBell]

Interesting story; thanks for sharing. I guess this one was about Carnotaurus-sized. But I don't think the specimen provides any specific evidence for feathers. Presumably the feathers are just speculation based on their prevalence in other dinosaur groups.

I got the same idea--it was more of a pargraph filling statement, rather than anything specific about new evidence. Likely written by someone not entirely familiar with paleontology.

[triceratops83]

Yeah, it doesn't say why they think it was feathered.

Aren't there skin impressions for Carnotaurus showing scales?

[MLMjp]

Yeah, it doesn't say why they think it was feathered.

Aren't there skin impressions for Carnotaurus showing scales?

Yes there are skin impressions. Althought that does not mean that it could not have feathers. It does mean that the animals is more likely to be scaly.

I'm not a fan of speculitative feathers and this article does not give me any reason or evidence to belive that abelisaurs had feather. I agree with most of you. The phrases that have feathers in this article feel like they are just there to fill some gaps on it

Anyway, abelisaurs trully got big!

[Patrx]

Whoah! Makes you wonder what else is locked away in museum collections, waiting to be studied.

Aren't there skin impressions for Carnotaurus showing scales?

Quite so, quite so, but that's the thing about fossilization - just because the filaments didn't show up doesn't mean they were never there. Anyway, my personal preference is to assume all theropods (at least) had fuzz of some kind, somewhere. Anyway, I think the illustrator just included them as part of the life reconstruction, it doesn't seem related to this specific study.

[HD-man]

Yes there are skin impressions. Althought that does not mean that it could not have feathers.

Quite so, quite so, but that's the thing about fossilization - just because the filaments didn't show up doesn't mean they were never there.

Don't forget that the only evidence we have of scales & feathers coexisting is on the feet of some owls & grouse.

[Sim]

I've been getting the impression that lately some people seem to be ignoring known scaly skin of dinosaurs when reconstructing them in favour of giving them a feather covering (over parts known to be scaly too), as if that would be more likely to be correct.  It feels like despite the variety in integument in birds today, there are people that think extinct theropods would have more or less the same body covering, despite fossils showing they had a greater variety in integument.  That's the impression I get from this article too, which has a life reconstruction of an abelisaur that completely ignores the very developed scales known from other ceratosaurs like Carnotaurus and Ceratosaurus, and twice mentions how they likely were covered in feathers, as if the enlarged scales of Carnotaurus and Ceratosaurus (which had osteoderms no less) didn't exist!

Mark Witton wrote a blog post about dinosaurs scales, where he mentioned noticing "some individuals understate just how good the records for scales in certain species are, this seemingly giving license to render a more speculative, but flamboyant body covering."  Here's the blog post, which also has photos of the Carnotaurus skin: http://markwitton-com.blogspot.co.uk/2015/12/dinosaur-scales-some-thoughts-for.html

It's true that feathers can grow between scales, but, it doesn't happen for no reason.  There are approximately ten thousand extant bird species, but how many of those have feathers growing between scales?  I know this occurs on owl feet.  Owls are farsighted, being unable to see anything within a few centimetres of their eyes clearly, the foot feathers allow them to feel caught prey.  Also, as far as I can see yo can still see the scales on owl feet with the fine feathers growing between them.  So the scales aren't completely hidden by feathers like in some dinosaur reconstructions.  I've heard feathers among scales also occurs on chickens which are bred by people to be like that, consequently that isn't an example of it naturally occurring.  It seems to me feathers among scales is something that happens extremely rarely and only with a very specific reason.

Something important to note is that scales aren't like bare skin, they are dermal structures like feathers and hair.

[Kovu]

I've been getting the impression that lately some people seem to be ignoring known scaly skin of dinosaurs when reconstructing them in favour of giving them a feather covering (over parts known to be scaly too), as if that would be more likely to be correct.  It feels like despite the variety in integument in birds today, there are people that think extinct theropods would have more or less the same body covering, despite fossils showing they had a greater variety in integument.  That's the impression I get from this article too, which has a life reconstruction of an abelisaur that completely ignores the very developed scales known from other ceratosaurs like Carnotaurus and Ceratosaurus, and twice mentions how they likely were covered in feathers, as if the enlarged scales of Carnotaurus and Ceratosaurus (which had osteoderms no less) didn't exist!

Mark Witton wrote a blog post about dinosaurs scales, where he mentioned noticing "some individuals understate just how good the records for scales in certain species are, this seemingly giving license to render a more speculative, but flamboyant body covering."  Here's the blog post, which also has photos of the Carnotaurus skin: http://markwitton-com.blogspot.co.uk/2015/12/dinosaur-scales-some-thoughts-for.html

It's true that feathers can grow between scales, but, it doesn't happen for no reason.  There are approximately ten thousand extant bird species, but how many of those have feathers growing between scales?  I know this occurs on owl feet.  Owls are farsighted, being unable to see anything within a few centimetres of their eyes clearly, the foot feathers allow them to feel caught prey.  Also, as far as I can see yo can still see the scales on owl feet with the fine feathers growing between them.  So the scales aren't completely hidden by feathers like in some dinosaur reconstructions.  I've heard feathers among scales also occurs on chickens which are bred by people to be like that, consequently that isn't an example of it naturally occurring.  It seems to me feathers among scales is something that happens extremely rarely and only with a very specific reason.

Something important to note is that scales aren't like bare skin, they are dermal structures like feathers and hair.

I'm really sad we don't have a "like" button because I'd give this post all the likes. All of them.

[stargatedalek]

While speculative, I wouldn't go so far as to say feathering a Ceratosaur is objectively incorrect. We have extensive impressions showing that many members of Neoceratosauria were extensively covered by scales, this of course includes Abelisaurs. This group of theropod is the only group where we can safely say for absolute certain that scales are the conservative reconstruction, but they are not obligatory on every member, just the conservative.

And given the recent evaluation of Concavenator's quill knobs soft integument is gradually becoming the norm among theropods in general. That's not to say everything should be covered head to toe in feathers, for example sparse feathering is for the moment the conservative among Carnosauria given the combination of Concavenator quill knobs and scale impressions from the underside of Allosaurus.

Feathers between scales is a fools errand. Yes many birds do display this, but it is limited to those that use them for very specialized purposes or bred specifically to display them. Feathers and scales are perfectly capable of coexisting on the same animal, but on different parts of the body.

[Sim]

I'm really sad we don't have a "like" button because I'd give this post all the likes. All of them.

Hehe, thanks!

And given the recent evaluation of Concavenator's quill knobs soft integument is gradually becoming the norm among theropods in general. That's not to say everything should be covered head to toe in feathers, for example sparse feathering is for the moment the conservative among Carnosauria given the combination of Concavenator quill knobs and scale impressions from the underside of Allosaurus.

From what I've seen there still isn't a consensus on Concavenator having quill knobs and there is still uncertainty about it among palaeontologists.  It is possible it did have them.  I must admit I'm still not convinced it had quill knobs though.  Concavenator preserves extensive scaly skin impressions too.  I've read about scaly skin from Allosaurus, but I think it said it was from the flank.  Unfortunately I can't find where I read about it at the moment.  Is there scaly skin known from the underside of Allosaurus?

[stargatedalek]

I was including flank as "underside", unless you're talking about skates or rays it can be hard not to have overlap in such descriptions

Unfortuneately I can't find the actual abstract, so it seems this Wikipedia summary must suffice:

https://en.wikipedia.org/wiki/Concavenator#cite_ref-concavenatorSVP2015_6-0

The hypothesis that the bumps along the ulna represented muscular insertion points or ridges was subsequently examined, and the results presented, at the 2015 meeting of the Society of Vertebrate Paleontology. Elana Cuesta, along with two of the researchers who initially described Concavenator (Ortega and Sanz), attempted to reconstruct its forearm musculature to determine if the ulnar bumps would be explained as an inter-muscular ridge. They identified the insertion point for the major arm muscles, and determined that the row of bumps could not have been located between any of them. They found that the only possibility was that the bumps could be an attachment scar for the M. anconeus muscle, which is unlikely, because this muscle normally attaches to a smooth surface without provenances on the underlying bone, and argued that the most likely explanation for the bumps was their initial interpretation as feather quill knobs. The authors admitted that it was unusual for quill knobs to form along the top surface of the bone, but also noted that the same arrangement is found in some modern birds, like the Moorhen.

Cuesta, E., Ortega, F., Sanz, J. (2015). Ulnar bumps of Concavenator: Quill Knobs or Muscular scar? Myological Reconstruction of the forelimb of Concavenator corcovatus (Lower Cretaceous, Las Hoyas, Spain). Abstracts of papers of the 75th Anuual Meeting of the Society of Vertebrate Paleontology: 111-112.

[Sim]

By "flank" I meant the side.  I found where I read about the Allosaurus skin, and it says the skin is from the left side of the body: http://dml.cmnh.org/2004Aug/msg00136.html

I saw that re the Concavenator ulnar bumps, but since then I've seen uncertainty expressed about those results by different palaeontologists, here's one example: http://theropoddatabase.blogspot.co.uk/2015/10/svp-2015-day-4.html

[stargatedalek]

I personally don't quite follow the reasoning, but it seems the author is arguing against the use of Corvus as a muscle reference in favor of crocodiles? They claim error on the part of Cuesta et al in regards to a seemingly arbitrary element of the interpretation. The author themselves even acknowledges that the structure is likely not analogues to muscle attachment and yet they also claim it doesn't represent quill knobs. Arguing against an interpretation without presenting an alternative is hardly a counter argument.

But I won't profess to understand muscle anatomy myself, so I may well have misinterpreted.

[HD-man]

I'm really sad we don't have a "like" button because I'd give this post all the likes. All of them.

Ditto.

[Dinoguy2]

Andrea Cau, who described this find and advised the artist directly, explains.
http://theropoda.blogspot.it/2016/03/miti-e-leggende-post-moderne-sui.html?m=1

Not sure why everybody thinks a few small patches from the belly and tail of Carnotaurus is evidence for a 100% scaly covering. Plenty of room for plausible speculation.

As Cau points out, there's zero evidence these are even scales. They're so poorly described they could just as easily be bumpy textured naked skin, or even like the skin of a plucked chicken. Nobody ever asked these questions when it was described because back then scales were the assumed default.

I'm not saying I think Carnotaurus had feathers, I'm saying we know basically nothing about its integument. "Basically nothing" being far better than we have for the vast majority of theropods, which we know exactly nothing about

[Patrx]

Andrea Cau, who described this find and advised the artist directly, explains.
http://theropoda.blogspot.it/2016/03/miti-e-leggende-post-moderne-sui.html?m=1

Not sure why everybody thinks a few small patches from the belly and tail of Carnotaurus is evidence for a 100% scaly covering. Plenty of room for plausible speculation.

Thanks for sharing that, Dinoguy! I just spotted it on Facebook and was on my way here to post about it myself.

[HD-man]

Andrea Cau, who described this find and advised the artist directly, explains.
http://theropoda.blogspot.it/2016/03/miti-e-leggende-post-moderne-sui.html?m=1

Is it just me, or does Cau's 1st paragraph come off as a bit hypocritical/elitist (not that I'm surprised, but still)? I couldn't help but be reminded of Engh's Youtube comment ("Specific to paleo, there are a lot of paleontologists who are great diggers, phylo trait mappers, geologists and fossil hunters, but simply don't have a good basis in the biology and ecology of living plants and animals, and therefor don't even realize when a life restoration of a given animal is awkward or completely implausible": https://www.youtube.com/watch?v=aQfBdBkmv94 ).

Not sure why everybody thinks a few small patches from the belly and tail of Carnotaurus is evidence for a 100% scaly covering.

Don't forget about the neck & shoulder.

[Patrx]

Is it just me, or does the 1st paragraph come off as a bit hypocritical/elitist (not that I'm surprised, but still)? I couldn't help but be reminded of Engh's Youtube comment ("Specific to paleo, there are a lot of paleontologists who are great diggers, phylo trait mappers, geologists and fossil hunters, but simply don't have a good basis in the biology and ecology of living plants and animals, and therefor don't even realize when a life restoration of a given animal is awkward or completely implausible.")

But Engh is spot-on correct in this regard - it's a major problem with palaeoart that has been noted by lots of other folks in the field, like Darren Naish, John Conway, and Matt Martyniuk. Some palaeontologists make lousy consultants regarding life reconstructions simply because that's not their area of expertise or even interest. Surely there's nothing "elitist" involved:

[HD-man]

But Engh is spot-on correct in this regard - it's a major problem with palaeoart that has been noted by lots of other folks in the field, like Darren Naish, John Conway, and Matt Martyniuk. Some palaeontologists make lousy consultants regarding life reconstructions simply because that's not their area of expertise or even interest.

That's basically what I said in my last post. If I may ask, what did you think I said?