citation#1 wrote:

Eleven feather or protofeather specimens...These fossils have disparate morphologies that span four evolutionary stages for feathers.

citation#1 wrote:
Specimens include filamentous structures similar to the protofeathers of nonavian dinosaurs that are unknown in modern birds, as well as derived bird feathers displaying pigmentation and adaptations for flight and diving.

citation#1 wrote:
...stage I morphology characterized by a single filament:

This is particularly important in the study of amber-entombed feathers because preservation is biased toward feather subcomponents, which provide the basis for our morphological comparisons.

Stage I is represented by UALVP 52821, which contains a dense forest of regularly spaced, flexible filaments with a mean diameter of 16.4 T 4.2 mm (Fig. 1B and figs. S1 to S4).

Their closest morphological match is the filamentous covering found of nonavian dinosaurs such as the compsognathid Sinosauropteryx prima (18). The amber-entombed specimens are slightly finer than those of Sinosauropteryx, which may have been distorted by compression and permineralization.

IMAGE SOURCE

... Dave's feathers also come in three types: simple hair-like fibers (primarily on the head and tail), sprays of fibers (apparent on the hind limbs and shoulders), and asymmetrical feathers like those of a modern bird (on the trailing edge of the arm).

IMAGE SOURCE

For example, the presence of dense filamentous feathers on Sinosauropteryx suggests these theropods were endothermic, and that heat retention was the primary function of the feathers.

citation#1 wrote:
The stage II morphotype (Figs. 1, C and D, and fig. S5) consists of tightly adpressed clusters approximately 0.2 mm in width and composed of filaments that are otherwise similar to those already discussed.

citation#1 wrote:The most morphologically comparable compression fossils are protofeathers associated with the dromaeosaurid Sinornithosaurus millenii

Specimens include filamentous structures similar to the protofeathers of nonavian dinosaurs that are unknown in modern birds, as well as derived bird feathers displaying pigmentation and adaptations for flight and diving.

Their closest morphological match is the filamentous covering found of nonavian dinosaurs such as the compsognathid Sinosauropteryx prima.

citation#1 wrote:
...additional specimens from Canadian amber have barbules specialized for discrete functions. In TMP 96.9.334 (Figs 2, A to C, and figs. S6 and S7) (10), a thickened rachis is surrounded by numerous barbules with tightly coiled bases.


Modern seedsnipes and sandgrouse possess belly feathers with similar basal barbule coiling, which allows water to be retained for transport to the nest for distribution to nestlings or for cooling incubating eggs. Grebes also have coiled barbules that absorb water into plumage, facilitating diving by modifying buoyancy, reducing hydrodynamic turbulence, and improving insulation .

On the basis of the presence of a rachis in TMP 96.9.334 and differentiated barbules in UALVP 52820, these specimens can be assigned conservatively to stages IV and V and are attributed to Late Cretaceous birds.

citation#1 wrote:
However, the discovery of endmembers of the evolutionary-developmental spectrum in this time interval, and the overlap with structures found only in nonavian dinosaur compression fossils, strongly suggests that the protofeathers described here are from dinosaurs and not birds.

citation#2 wrote:
Supporting Online Material for
A Diverse Assemblage of Late Cretaceous Dinosaur and Bird Feathers from Canadian Amber

Ryan C. McKellar, Brian D. E. Chatterton, Alexander P. Wolfe, Philip J. Currie

Published 16 September 2011, Science 333, 1619 (2010)
DOI: 10.1126/science.1203344

A suite of modern bird feathers and hair samples were directly compared to the amber-entombed specimens, as were morphological atlases on the microscopic structure of mammalian hairs (30, 31) and feathers (24, 25).

Sinosauropteryx prima comparison In terms of compression fossils, the Stage I morphotype filaments observed in Canadian amber are most comparable to protofeathers from Sinosauropteryx prima. The integumentary structures of S. prima display a range of lengths, from ~4 mm to at least 4.0 cm, depending on the specimen and their body position . These independent filaments range in thickness from easily observed 0.2 mm filaments to those that are considerably smaller than 0.1 mm. The filaments are hollow and round in crosssection and may have been secondary branches of larger structures or isolated filaments. Although the UALVP 52821 specimen does not display filaments with diameters as large as the maximum reported from S. prima, they are consistent with the finer filaments found in this specimen, and fall within the range of observed lengths.

The UALVP 52822 clustered filaments described as a Stage II morphotype are most similar to compression fossils surrounding Sinornithosaurus millenii. In S. millenii, although there is no direct evidence of a rachis (as with the amber specimens), barbules are clearly clustered into independent tufts with compressed widths of 1–3 mm and lengths of up to 4.5 cm (12, 20). These clustered filaments appear to have been attached basally, or in one example, inferred to have arisen from a central rachis (12, 20). Although no direct measurements of the filaments that comprise each cluster have been presented by Xu et al (20) they appear to be of sub-millimeter diameter similar to the filaments observed in amber. As in the Sinosauropteryx prima protofeathers, the clusters found with Sinornithosaurus millenii are likely to have expanded diameters as a result of filament splaying during compression.

link

"Spectacular fossils from the Early Cretaceous Jehol Group1, 2 of northeastern China have greatly expanded our knowledge of the diversity and palaeobiology of dinosaurs and early birds, and contributed to our understanding of the origin of birds, of flight, and of feathers. Pennaceous (vaned) feathers and integumentary filaments are preserved in birds, and non-avian theropod dinosaurs, but little is known of their microstructure. Here we report that melanosomes (colour-bearing organelles) are not only preserved in the pennaceous feathers of early birds, but also in an identical manner in integumentary filaments of non-avian dinosaurs, thus refuting recent claims, that the filaments are partially decayed dermal collagen fibres. Examples of both eumelanosomes and phaeomelanosomes have been identified, and they are often preserved in life position within the structure of partially degraded feathers and filaments. Furthermore, the data here provide empirical evidence for reconstructing the colours and colour patterning of these extinct birds and theropod dinosaurs: for example, the dark-coloured stripes on the tail of the theropod dinosaur Sinosauropteryx can reasonably be inferred to have exhibited chestnut to reddish-brown tones".
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Our results demonstrate conclusively that the integumentary filaments of non-avian theropod dinosaurs are epidermal structures. In birds, melanin is synthesized endogenously in specialized pigment-producing cells, melanocytes, that occur primarily in the dermis; the melanocytes migrate into the dermal pulp of the developing feather germ, where the melanin is packaged into melanosomes and then those melanosomes are transferred to keratinocytes for deposition into developing feathers. In various avian species melanin granules also form, and are apparently retained, in dermal melanocytes; melanin granules can form a discrete layer in the dermis, but below, and not as part of, the collagen layer. The occurrence of melanosomes embedded inside the filaments of Jehol non-avian dinosaurs thus confirms that these structures are unequivocally epidermal structures, not the degraded remains of dermal collagen fibres, as has been argued recently. Our work confirms that these filaments are probably the evolutionary precursors of true feathers, and it will be interesting to determine whether any fossil filaments might relate to other kinds of epidermal outgrowths in modern birds.
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In Sinornithosaurus the filaments are locally dominated either by eumelanosomes or phaeomelanosomes, indicating significantly different colour tones. In Confuciusornis, variation in colour within a single feather is indicated by changes in the relative abundance of phaeomelanosomes and eumelanosomes over short distances. Only phaeomelanosomes have been identified so far in filaments from the tail of Sinosauropteryx, and this suggests that the dark-coloured stripes along the tail in the fossil, and possibly also the filamentous crest along the back, exhibited chestnut to rufous (reddish-brown) tones.

The idea of feathered dinosaurs and the theropod origin of birds is being actively promulgated by a cadre of zealous scientists acting in concert with certain editors at Nature and National Geographic who themselves have become outspoken and highly biased proselytizers of the faith. Truth and careful scientific weighing of evidence have been among the first casualties in their program, which is now fast becoming one of the grander scientific hoaxes of our age---the paleontological equivalent of cold fusion.

Blood wrote:This reminds me of something I've been wanting to ask your guys for a long time.
snip...

I read some other stuff from Olson, independent of the Archaeoraptor, where he denigrates the dinosaurs-to-birds evolutionary paradigm. I thought this was essentially accepted by everyone in the natural sciences now? Is it actually "controversial"?

Shrunk wrote:

ughaibu wrote:

quisquose wrote:Then I felt an enormous sadness at the thought that, whilst I was thrilled at the news, a significant percentage of the population was likely to be shaking their heads and muttering "it's all lies".

I dont think I've ever met an evolution denier in the UK. Is there a documented significant percentage?

This poll suggests the prevalence is not much different than that of the US:

http://www.telegraph.co.uk/news/religio ... ution.html

hackenslash wrote:Incidentally, theropod, keep an eye out for a new show called Planet Dinosaur, which should be hitting a youtube near you very soon (already available on i-player, I think). This week's episode was about theropods to aves, and was excellent (lots of CGI and detail about how they discern the colours of the feathers, etc.)

Also, this week's Horizon was a guide to dinosaurs, compiled from several decades of episodes on just that. Truly excellent, both.

hackenslash wrote:Incidentally, theropod, keep an eye out for a new show called Planet Dinosaur, which should be hitting a youtube near you very soon (already available on i-player, I think). This week's episode was about theropods to aves, and was excellent (lots of CGI and detail about how they discern the colours of the feathers, etc.)

Also, this week's Horizon was a guide to dinosaurs, compiled from several decades of episodes on just that. Truly excellent, both.

JoeB wrote:Speaking of building a dinosaur, the fun that can be had with this suit is awesome! (although now they have to rebuild it with feathers apparently.

ughaibu wrote:

quisquose wrote:Then I felt an enormous sadness at the thought that, whilst I was thrilled at the news, a significant percentage of the population was likely to be shaking their heads and muttering "it's all lies".

I dont think I've ever met an evolution denier in the UK. Is there a documented significant percentage?

Horwood Beer-Master wrote:

hackenslash wrote:Incidentally, theropod, keep an eye out for a new show called Planet Dinosaur, which should be hitting a youtube near you very soon (already available on i-player, I think). This week's episode was about theropods to aves, and was excellent (lots of CGI and detail about how they discern the colours of the feathers, etc.)

Also, this week's Horizon was a guide to dinosaurs, compiled from several decades of episodes on just that. Truly excellent, both.

There's also "How to Build a Dinosaur" presented by Dr Alice Roberts - which featured a small segment with Darren "Tet Zoo" Naish.

hackenslash wrote:

Horwood Beer-Master wrote:

hackenslash wrote:Incidentally, theropod, keep an eye out for a new show called Planet Dinosaur, which should be hitting a youtube near you very soon (already available on i-player, I think). This week's episode was about theropods to aves, and was excellent (lots of CGI and detail about how they discern the colours of the feathers, etc.)

Also, this week's Horizon was a guide to dinosaurs, compiled from several decades of episodes on just that. Truly excellent, both.

There's also "How to Build a Dinosaur" presented by Dr Alice Roberts - which featured a small segment with Darren "Tet Zoo" Naish.

The problem with anything presented by ALice Roberts is that it's difficult to focus on the material, IYKWIMAITYD.