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Terrible new paper
Lingham-Soliar, 2003. Evolution of birds: ichthyosaur integumental fibers
conform to dromaeosaur protofeathers. Naturwissenschaften.
Abstract: Filamentous integumentary structures have been reported as
protofeathers in dromaeosaurs (non-avian dinosaurs). This hypothesis is
considered against data on the complex architecture of dermal and subdermal
collagenous fibers widely prevalent in living and extinct animals.
Ichthyosaur integumental fibers, as dromaeosaur "protofeathers", are the
most external structures preserved. Marked similarities are shown in
branching patterns of these fibers compared with those of the dromaeosaur
Sinornithosaurus; hence distinguishing between aberrant and primary features
is difficult. Analysis of a pterosaur specimen shows that bent and straight
fibers on the wings have functional implications. The fibers conform to the
twofold shape of collagen and contradict the notion that bent integumental
structures in the dinosaur Sinosauropteryx indicate softness and pliability.
A suggestion also concerning Sinosauropteryx is that integumental structures
with darker edges, compared with the middle, imply that they were hollow.
Investigation of a similar condition in an ichthyosaur shows that it is more
likely a consequence of mineralization. Dermal collagen fibers in, for
example, sharks, dolphins, snakes, and turtles are shown to be grouped in
bundles of varying sizes. Degradation of the dermis results in the breakdown
of the fiber bundles and formation of myriad patterns of the disrupted
fibers, as noted in decomposed dolphin skin. The overall findings of the
study are that the thesis of dinosaur "protofeathers" requires more
substantial support than exists at present.
This paper tries to equate stage I-III dromaeosaur and Sinosauropteryx
feathers with our friend the collagen fiber. I must say none of the
photographed collagen fibers look much like feathers, though figure 1d comes
closest. Let's critique some aspects-
"Titles of articles (Xu et al. 2001; Ji et al. 2001) that proclaim
"feathered dinosaurs" actually describe integumentary fibers or feather-like
structures, which are not the same as avian feathers, as some of these
authors recently noted (Norell et al. 2002)."
Alas, despite referencing Prum (1999), Lingham-Soliar apparently missed his
definition of feather, which includes filaments (stage 1) and tufts (stage
"The subject necessitates that the suggested presence of protofeathers in
dinosaurs must be proven or rejected based on incontrovertible evidence,
especially given the presence of similar filamentous structures in other
groups of fossilized archosaurian and non-archosaurian reptiles (Mayr et al.
2002; Wang et al. 2002; Lingham-Soliar 2001) and mammoths (Kukhareva and
But the presence of nearly identical structures in unambiguously feathered
dinosaurs (eg. Protarchaeopteryx, Caudipteryx) is never mentioned, despite
the time spent on dissimilar structures in marine animals. Indeed,
Protarchaeopteryx and Caudipteryx are never mentioned, nor are their
descriptions (eg. Padian et al., 2001) referenced. I love how it's always
assumed that feathered pterosaurs or psittacosaurs are so improbable that
the presence of apparent stage 1 feathers on either would make us doubt
their presence in coelurosaurs.
"The dromaeosaur tail is a relatively stiff organ, achieved by powerful
bands of ligaments that extend along the dorsolateral and ventrolateral
surfaces of the tail vertebrae."
Well, someone sure does understand dromaeosaur anatomy.
"Two possible scenarios are envisaged in Sinosauropteryx: either the bundles
of tightly strung ligaments broke contact with the vertebrae during
post-mortem decay and came to lie alongside the caudal vertebrae, or the
skin possessed masses of strengthening fibers or rays vertically orientated
to the long axis of the body."
Who knew Sinosauropteryx needed so many ligaments attached to its frontal.
And why are all the "strengthening fibers" oriented posteriorly at an angle
if they were vertically oriented in life? Also notice the feathers on other
areas (eg. ribcage, behind skull, arm) are ignored.
"It was not so long ago that pterosaurs covered in hair pervaded
reconstructions (e.g., see Wellnhofer 1991), an unfortunate interpretation
of Sharov's (1971) description of hair-like structures in Sordes pilosus.
More recently, however, the structures were shown to be fibers supporting
the wings (Unwin and Bakhurina 1994), straight, closely packed fibers on the
outer half of the wing and shorter, loosely packed fibers close to the
Apparently Lingham-Soliar suffers from Feducciitis- the inability to realize
Unwin and Bakhurina weren't talking about ALL the fibers in Sordes, and that
Unwin and most (all?) other pterosaur workers do believe pterofur is
"It is impossible to say that the famous Chinese dromaeosaurs did not
possess feathers, or that they
are not collagen fibers, which has been suggested as the biological material
preserved in these dinosaurs (Feduccia 1999)."
Recall when he referenced Norell et al.'s (2002) preliminary description of
Cryptovolans above? Well, that's the only time it's mentioned in the text.
A bit unscientific to say that Norell et al. noted previous reports of
dromaeosaur feathers were not unambiguously stage 3 or higher, but fail to
mention THAT VERY PUBLICATION'S purpose was to report advanced feathers in a
Anyway, it's clear that recent discoveries like Cryptovolans and Microraptor
gui prove dromaeosaurs were feathered. It's also clear the very fact no
non-dinosaurian, non-pterosaurian Yixian taxa preserve these filaments
indicates they are not collagen fibers. Thus, the paper's thesis is easily
disproved, making it useless.