Thanks to Rob Taylor of the Theropod Archives who just posted on the Dinosaur Mailing List that Naturwissenschaften is freely available online through the end of the month. One of several Online First Titles that is of interest is this one...
Voight, S., Buchwitz, M., Fischer, J., Krause, D., and R. Georgi. Online First 2008. Feather-like development of Triassic diapsid skin appendages. Naturwissenschaften
Abstract - Of the recent sauropsid skin appendage types, only feathers develop from a cylindrical epidermal invagination, the follicle, and show hierarchical branching. Fossilized integuments of Mesozoic diapsids have been interpreted as follicular and potential feather homologues, an idea particularly controversially discussed for the elongate dorsal skin projections of the small diapsid Longisquama insignis from the Triassic of Kyrgyzstan. Based on new finds and their comparison with the type material, we show that Longisquama’s appendages consist of a single-branched internal frame enclosed by a flexible outer membrane. Not supporting a categorization either as feathers or as scales, our analysis demonstrates that the Longisquama appendages formed in a two-stage, feather-like developmental process, representing an unusual early example for the evolutionary plasticity of sauropsid integument.
The PDF and online supplemental material is also available from the same site.
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