Feathered carnosaurs?

[gigadino96]

Were carnosaurs feathered? Why/why not? On the web, I found some feathered carnosaurs, such as this:

[theropod]

They probably were feathered in the wider sense, even megalosauroids may have been (and so where heterodontosaurs, pterosaurs and neoornitischians).
Whether their feathering would be as prominent as portrayed or rather comparable to the sparse fur of a rhino or elephant (I usually bring that up because then I don’t have to change every single one of my drawings lol) is another matter and was likely subject to considerable variability (depending on the climate among other things), but I personally really like the Allosaurus you posted.

[Derdadort]

I know it's very speculative, but I would say that most ornithodirans had at least a small amount of filaments. As for carnosaurs respectively Allosauroidea Concavenator is probably the only genus with supposed protofeathers. However, there are still some uncertanities: scienceblogs.com/tetrapodzoology/2010/09/09/concavenator-incredible-allosauroid/

[Deleted]

Feathered carnosaurs? Nope, at least not in the way depicted in the picture above.

The only carnosaurian skin impressions ever found(skin impressions of Allosaurus) show scales.

Don't believe me? Then here: dml.cmnh.org/2004Aug/msg00136.html

The art above is good, but it makes Allosaurus look like a basal tyrannosauroid(to me, at least) and is not really based on actual evidence(link above).


theropod: I'm using the more strict definition here.

Filaments on carnosaurs? Sure thing. Just not too extensive.

[theropod]

Not that again. When scientists say feathers, they are not just referring to avian compound feathers, but to all filaments homologous to those. Feathers are thus a diverse kind of integument ranging from simple monofilaments (hence "stage one feathers") to the avialan flight feather.

If you consider skin impressions (which I do think indicates a limit on the size and concentration of the filaments, but by no means that there were none present) as evidence against feathers, then you also have to consider it evidence against other types of filaments. Taphonomy doesn’t care about sematics.

And there is indication of feathers in Carnosaurs. Ortega et al. 2010 describe an ulna of Concavenator with a row of small tubercles resembling quill-knobs, and the structures on the bone figured in Fig. 4a and 4b are very similar to those seen on the ulna of the turkey vulture included in 4c for comparison.
You may favour an alternate explanation, but you cannot deny that these being evidence of feathers is a good possibility.

---

Reference:
Ortega, Francisco; Escaso, Fernando; Sanz, José L.: A bizarre, humped Carcharodontosauria (Theropoda) from the Lower Cretaceous of Spain. Nature, vol. 467 (2010); pp. 203-206

[Derdadort]

A bit OT, but: is Carnosauria still used? I thought it is more or less synonymous with Allosauroidea

[creature386]

Typing Carnosauria in Google Scholar and only allowing papers that came in 2014 says yes.
They are not even synonyms, Allosauroidea is a clade within Carnosauria. Carnosauria includes allosauroids plus taxa such as Fukiraptor, Lourinhanosaurus and Siamotyrannus.

[Derdadort]

But Fukuiraptor and Siamotyrannus are considerded to be allosauroids in recent papers (Neovenatoridae and Metriacanthosauridae), Lourinhanosaurus is after Carrano (2012) even a coelurosaur. If Google Scholar shows the same papers from 2014 for me as for you, the most papers are either in fact older than 2014 or the term only appears in the references.
I know that Carnosauria was considerded to be the parent taxon of Allosauroidea, but I imagined the definition for Carnosauria and Allosauroidea were very similar like in Dromaeosauridae and Deinonychosauria, so they would be de facto the same. As for Carnosauria the only definition I found is "everything more related to Allosaurus than to modern birds".

[theropod]

Fukuiraptor is actually a megaraptoran. Some nest them deeply within carcharodontosauria, others within coelurosauria.

It depends on whose definition you use. There have been uses of a stem-based Allosauroidea that are basically synonymous with Carnosauria.
However they have also been defined as a node-based taxon compromising Allosaurus+Sinraptor+Carcharodontosaurus, and this is the most commonly used meaning of the word, while Carnosauria (I know, this term sounds so old-fashioned, doesn’t it? For decades it was basically applied to all large theropods) remain the stem-based sister-taxon to Coelurosauria (all neotetanurans/avetheropods closer to Allosaurus fragilis than to Passer domesticus).

[Deleted]

Sept 28, 2014 20:56:38 GMT 5 theropod said:

If you consider skin impressions (which I do think indicates a limit on the size and concentration of the filaments, but by no means that there were none present) as evidence against feathers, then you also have to consider it evidence against other types of filaments. Taphonomy doesn’t care about sematics.

And there is indication of feathers in Carnosaurs. Ortega et al. 2010 describe an ulna of Concavenator with a row of small tubercles resembling quill-knobs, and the structures on the bone figured in Fig. 4a and 4b are very similar to those seen on the ulna of the turkey vulture included in 4c for comparison.
You may favour an alternate explanation, but you cannot deny that these being evidence of feathers is a good possibility.

---

Reference:
Ortega, Francisco; Escaso, Fernando; Sanz, José L.: A bizarre, humped Carcharodontosauria (Theropoda) from the Lower Cretaceous of Spain. Nature, vol. 467 (2010); pp. 203-206

Oops, should have specified what I meant, my bad.

I don't doubt that Concavenator could have display quills in it's arms, but Darren Naish apparently thinks those could simply be ossified attachment sites for tendon sheets.

[theropod]

"Could" is the key point.
My main concern that makes me think the interpretation as quill-knobs is more likely is that all animals have tendons and muscles, and that there’s nothing that makes me think the forelimbs of Concavenator were greatly different from those of other theropods.
So if these structures were linked to those, we’d find them with some consistency in various theropod bones–but we don’t, implying the reason for them is a more variable factor, like integument.

[Cross]

The 2003 SVP Abstracts includes an abstract on page 87a by Pinegar et al. describing a juvenile Allosaurus with a preserved skin patch measuring 30^2 centimeters wide with 2-3mm wide scales along it. The specimen was around 4 meters long, so Allosaurids were scaly. Carcharodontosaurids may have had protofeathery filaments combined with scales as indicated by Concavenator (Ortega et al. 2010). Though since the holotype Concavenator has a decent amount of scales along with the supposed ulnar quill knobs (which have been suggested to be ligament scars instead), I personally believe based on this that carnosaurs were dominantly scaly and probably had keratinous quills/filaments only on minor areas such as the forearm, cervicodorsal area, and perhaps the tail. A carnosaur covered in protofeathers or pennaceous feathers is out of the question IMO.

"A JUVENILE ALLOSAUR WITH PRESERVED INTEGUMENT FROM THE
BASAL MORRISON FORMATION OF CENTRAL WYOMING
PINEGAR, Richard Tyler, Provo, UT; LOEWEN, Mark A., Utah Museum of Natural History,
Salt Lake City, UT; CLOWARD, Karen C., HUNTER, Rick J. Western Paleo Laboratories,
Lehi, UT; and WEEGE, Christopher J., EnCana Oil and Gas (USA) Inc., Denver, CO.

"Recent excavations at the Meilyn Quarry near Medicine Bow, Wyoming have produced
a large adult allosaur and a new specimen interpreted as a juvenile of the same species. They were recovered 11 meters above the base of the Morrison Formation within a fine-grained
sandstone with depositional features indicating an ephemeral fluvial system. Taphonomic
indicators, including a high degree of articulation and skin impressions, argue for little to no
fluvial transport and the presence of soft tissues at the time of burial.
Disarticulated cranial material includes both dentaries, surangulars, prearticulars, splenials,
hyoids, jugals, quadratojugals, quadrates, squamosals and pterygoids, right articular,
maxilla, palatine and vomer, left postorbital and prefrontal, and a partial braincase. Most of
the vertebral column, ribs and gastralia are represented, except the atlas, axis and some midcaudals.
Limb materials include shoulder girdles, forelimbs and the right hindlimb. The left
side of the body preserves a 30 cm2 skin impression consisting of small scales 2-3 mm in
diameter. This suggests that juvenile allosaurs possessed scaly integument. This represents the
most derived tetanuran to retain this character, otherwise present in more basal theropods such
as Carnotaurus.
Overall length of the specimen is estimated at 4 m with a hip height of 1 m and skull
length of 36 cm, suggesting that this animal is a juvenile. Furthermore, size-independent morphological
characteristicsóincluding open cranial and postcranial sutures, forelimb and
hindlimb proportions, and juvenile bone surface textureóare also indicative of a juvenile
specimen.
Comparisons with juvenile and adult allosaur material from the Cleveland-Lloyd
Quarry, and material of a new allosaur (DINO 11541), suggest that this new specimen is not
Allosaurus fragilis, based primarily on a relatively flat ventral jugal margin, and the shape of
the caudal neural spines. These characters together with a wide obturator notch on the pubis
of the adult specimen are consistent with characters present on DINO 11541, suggesting that
these two animals belong to a distinct species of Allosaurus."

Source : www.miketaylor.org.uk/tmp/svp-abstracts/SVP%202003%20abstracts.pdf (page 87a).

[theropod]

IMO someone should document the modes of decomposition of scales and feathers experimentally, using pieces of feathered and scaly bird skin and scaly crocodilian or squamate skin, and maybe some artificial mixture of both feathers and scales to simulate a patch of skin on which both were present simultaneously.
I find it very unlikely that compact scales decompose at the same rate as delicate filaments, so by inference scales should have a higher chance of preservation under the same taphonomic circumstances.

[Cross]

Jan 21, 2016 20:05:19 GMT 5 theropod said:

IMO someone should document the modes of decomposition of scales and feathers experimentally, using pieces of feathered and scaly bird skin and scaly crocodilian or squamate skin, and maybe some artificial mixture of both feathers and scales to simulate a patch of skin on which both were present simultaneously.
I find it very unlikely that compact scales decompose at the same rate as delicate filaments, so by inference scales should have a higher chance of preservation under the same taphonomic circumstances.

Are you suggesting that the said specimens of Concavenator and Allosaurus protofeathers which were decomposed upon preservation? 
Because the scales present on both specimens does not resemble the same integument that has room for feathers to grow on other ornithodirans. I.E There don't seem to be any bases for filaments to grow on. The scales appear really compact and resemble those of other dinosaur clades that are known to be scaly, such as hadrosaurids and sauropods (Chiappe et al. 1998; Bell 2013). 



I also found a publication relevant to your statement about taphonomic factors and conditions on feathered and scaly ornithodirans, but this paper only touches the sediments and possible mode of decomposition : www.researchgate.net/profile/Elena_Cuesta/publication/273127149_Taphonomic_study_of_Concavenator_Corcovatus_(Theropoda_Carcharodontosauria)_from_Las_Hoyas_fossil_site_(Lower_Cretaceous_Serrana_de_Cuenca_Spain)/links/54f82d2c0cf2ccffe9dd172a.pdf 

[theropod]

Jan 27, 2016 11:23:34 GMT 5 Cross said:

Jan 21, 2016 20:05:19 GMT 5 theropod said:

IMO someone should document the modes of decomposition of scales and feathers experimentally, using pieces of feathered and scaly bird skin and scaly crocodilian or squamate skin, and maybe some artificial mixture of both feathers and scales to simulate a patch of skin on which both were present simultaneously.
I find it very unlikely that compact scales decompose at the same rate as delicate filaments, so by inference scales should have a higher chance of preservation under the same taphonomic circumstances.

Are you suggesting that the said specimens of Concavenator and Allosaurus protofeathers which were decomposed upon preservation? 
Because the scales present on both specimens does not resemble the same integument that has room for feathers to grow on other ornithodirans. I.E There don't seem to be any bases for filaments to grow on. The scales appear really compact and resemble those of other dinosaur clades that are known to be scaly, such as hadrosaurids and sauropods (Chiappe et al. 1998; Bell 2013). 



I also found a publication relevant to your statement about taphonomic factors and conditions on feathered and scaly ornithodirans, but this paper only touches the sediments and possible mode of decomposition : www.researchgate.net/profile/Elena_Cuesta/publication/273127149_Taphonomic_study_of_Concavenator_Corcovatus_(Theropoda_Carcharodontosauria)_from_Las_Hoyas_fossil_site_(Lower_Cretaceous_Serrana_de_Cuenca_Spain)/links/54f82d2c0cf2ccffe9dd172a.pdf 

Before preservation, yes. Obviously speed of decomposition is related to surface/volume ratios.

I don't think there are any photographs of the Allosaurus specimen in question. As for Concavenator, we've got evidence of both feathers and scales, yet only the scales were preserved, which I think sort of proves my point.

How do you know hadrosaurs and sauropods didn't have feathers too? Its basically the same situation as with theropods.