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Lingham-Soliar's Review of Chinese Fossil Preservation

...or, an article that can be summed up by the following rhetoric:

  "On this 200th anniversary of the birth of Charles Darwin, perhaps the 
greatest evolutionary biologist of all time, I ask, has the care and caution 
that characterized Darwin’s work taken a downward spiral in many of the 
evolutionary interpretations associated with the fossils from China today? Good 
fossils or bad science?" -- Theagarten Lingham-Soliar, 2009 (J. Ornith, in 

  It is not enough, perhaps, to perform the work, or even make the comparisons, 
but to also have the framework established on which your theory is based. 
Lingham-Soliar begins his paper with a quote:

  "'Assuming an answer before the investigation has begun is an all-too-common 
human failing…an abandonment of the intellectual process.' - Ralph Ellis 2002 

  In the past decade, TLS (for short) has done some pretty decent (downright 
good) exploratory work on the structure of the dermal tissues of fossils. This 
began with many marine reptiles (ichthyosaurs, mosasaurs) and provided data 
that supported the lattice-like structure of the skin collagen, as seen in 
dolphins (among other animals). He then turned his attention to our tiny 
"fluffy" friends from China who, among other things, suffer the fault of being 
preserved in an anoxic dump at the bottom of a ash-layered lake, unlike the 
more expedient and perhaps pleasant preservation at the bottom of a simply 
anoxic, limestone-layered lagoon, such as the Solnhofen Formation. As if their 
life wasn't already hard.

  Fossils from the Jehol Biota (predominately the non-basal Yixian and the 
Jiufotang Formations) preserve almost unerringly with "haloes" of degraded 
integumentary tissues, assumed to be decomposition from the skin, muscles, 
ligaments, and even extradermal tissues like "hair" and "pycnofibers" and 
"dinofuzz" and yeah, even "feathers." (note: the basal Yixian does not 
preserved "haloes.") This preservation is uncanny, and resembles that seen in 
the Messel Formation of Germany, the Quercy of France, portions of the Eocene 
Green River Formation, and others. Dermal structures are so ubiquitous in 
Messel that the associations of shape and structure are uncontested with their 
identification as "hair" or "feathers." The real question not asked in the 
opening paragraph of TLS's latest paper, should have been "What other animals 
preserved like this?" 

  A quick check would have produced quite a variety of birds and mammals. It 
would not preserve lizards, snakes, frogs, or turtles, or even crocodilians, 
with frayed, ragged margins of their "haloes" seeming like tufts of "hair" or 
"feathers." Solnhofen, for example, preserves crocodilians, pterosaurs, and 
even lizards with clean, smooth margins for their haloes. The Yixian preserves 
pterosaurs, mammals, birds, etc., all with "haloes" and all, to this date, 
uncontested as to their integumentary preservation. This is, however, not the 
case for the (obligatorily, "non-avian") dinosaurs preserved here.

  Most recently, TLS has turned his attention to two "cornerstone" fossils in 
the "feathered" dinosaur debate: *Sinosauropteryx*, which practically started 
this whole thing and led to such euphemisms as BAND (Birds are Not Dinosaurs, 
who look for any reason to determine this); and *Psittacosaurus*, which is 
known to include specimens with particularly fascinating "quills" sticking out 
over the hips and tail. In the former, debate has focused on one of two things: 
branching of the fibers present, and continuity and placement of the fibers; in 
the latter, the idea that these "quills" are collagen has never been raised, 
and thus, it has never been tested ... by anyone. The latest paper is a review 
of this work, and it is thus necessary to refer to this as we discuss the 

  In the latter, TLS has examined material (MV53; TLS, 2008, _Proceedings of 
the Royal Society, London B_ 275:775–780) that differentiates sections of 
"skin" apart from the "quills" which show a lattice structure that has been 
noted in ichthyosaurs. This is distinct from that of the tail structures, and 
there is an accompanying "halo" around the animal that is regular, 
smooth-margined, and does not seem at all like it's "hairy." This paper is 
probably one of the more important pieces of this puzzle, and why TLS is 
(rightly) accreditable for doing primary work on determining the structure of 
the skin in many fossil organisms. The reason, however, is that he is capable 
of showing the structure of the skin fibres in an animal that does not, in any 
case, seem "feathered" or "hairy." When TLS turned his attention to 
*Sinosauropteryx* (TLS, Feduccia and Wang, 2007, _Proceedings of the Royal 
Society, London B_ 274:1823–1829), reapproaching the work done by Currie and 
Chen (2001, Canadian Journal of Earth Sciences 38:1705–1727), this 
investigative finding, which had previously yielded results from sharks and 
ichthyosaurs, was missing. 

  One should note here that the "lattice" of collagen is noticeable: There is a 
system of primary and wholly parallel fibers, and a contrary, almost 
perpendicular system that appears as a weave of black lines (or colored, 
depending on the preservational medium, and in the Yixian, it's colored). When 
we find this absent, we do not assume therefore that this system is 
representative of a collagen lattice, as appears in skin. Instead, we assume 
there are other things present. For example, when TLS et al. looked at 
*Siunosauropteryx*, they found two sets of structures, including bundles of 
tightly parallel fibres between the chevrons, and the remainder as looser, 
apparently "branched" fibers as part of the "halo." Of course, some of the 
fibres in the "halo" are not branched, and at a resolution that is much broader 
and therefore not as close as seen in *Psittacosaurus* or in the work done 
earlier on ichthyosaurs when the scale was in the micron, not the centimeter 
(although I am being slightly disingenuous as some of this work has the 
scalebars in the _millimeters_, but that's hardly close to the resolution using 
SEM for *Psittacosaurus* in the study one year later and several years earlier 
for other taxa), they do _seem_ similar. The regular spacing of the fibers in 
TLS et al. (fig. 3a) really does seem very neat and tidy, and as it comes from 
the tip of the tail, we can assume this is part of the "halo" and not material 
like the deep skin structures shown in fig. 4.

  In an act of shortsightedness, perhaps, TLS describes for one taxon at a 
higher resolution than another, perhaps more problematic one, and does so one 
year later. Lacking the SEM study, we are left with personal, manual 
microscopic analysis, and in this, TLS does not disappoint. Almost amazingly, 
Currie and Chen described for *Sinosauropteryx* "hollow" fibers, with a 
distinct reference to a collapsed tubular morphology as shown by single strands 
having a light, inner core surrounded on each side by a darker, denser rim. 
This is characteristic in collapsed tubes, as TLS affirms this when referring 
to the "EBFF"s of Xu et al in his latest paper. It is significant that when 
Currie and Chen described this, TLS does not when he describes a "beaded" 
aspect with sinuousness to the *Sinosauropteryx* fibers. The omission is 
telling as in TLS et al., the word "hollow" appears but once, in connection to 
the *Sinosauropteryx* fiber descriptive paper (Chen, Dong, Zheng, 1998, 
_Nature_ 391:147–152) (to which Currie and Chen is a follow up), and because 
TLS describes the hollowness of the *Psittacosaurus* fibers in the latest paper.

  Stepping beyond the framework that TLS himself established, however, he 
begins to argue that others have not performed adequate descriptive work to 
determine the structure of the "haloes" and other preserved fibers in (again, 
obligatorily, "nonavian") dinosaur fossils from China. This results in most of 
the paper's body, which is a detailed (and rhetorical) review of various 
short-form/long-abstract papers from _Nature_ and _Science_ (for the most 
part). He details herein many perceived faults, primarily that the workers 
begin using the term "feathers" instead of a more generic phrase.

  I stress, now, that my argument of "nonavian" dinosaurs is important: TLS 
himself has done work to determine the microstructure of fossil marine reptile 
skin, comparison to sharks, etc., and then transfered this direct attention to 
the Liaoning fossils. I argue that TLS has faltered in the framework he argues 
others did not follow; this is apparent also in the review works of Feduccia 
and others who have written extensively as counterarguments to the "birds are 
dinosaurs" theory that is so contentious here. The basis for this faltering is 
thus: TLS has not examined the structure (and comparability) of the fibers to 
those found in birds and mammals, and done so also outside of Liaoning. It 
should be important, as some fossils (such as *Confuciusornis*) have been 
described which seemingly sport non-pennaceous feathers, while at the same 
time, many, many mammals are know with extensive "haloes" that go 
uncontentested as to their identity. 

  I hesitate to offer an hypothesis as to this faltering, but given that TLS 
has written twice (both methodological) with Feduccia, who is an outstanding 
critic and opponent of the theory of avian descent from within theropod 
dinosaurs (or really, dinosaurs and potentially the dinosaur/bird--crocodilian 
group of reptiles, and even archosaurs in general), it becomes apparent that 
the framework is not only at fault (not for being faulty itself, but for being 
insufficient), it is also its perspective that is in error. Were we to argue 
that we could only use one group of animals to establish a perspective from 
which to view fiber arrangements, and this group bore no integumentary 
structures beyond the surface of its skin; stepping out of this box, we can 
look at animals that have both several types of integumental structures, and 
those that do not, and form a spectrum of comparison. TLS did not only refrain 
from doing this, he has done so repeatedly with coauthors whom appear to have a 
"hidden" agenda. Without a sharp focus on the perspective in which a framework 
is made, the framework fails, and for TLS, I fear it has done so terribly.


Jaime A. Headden

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)

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