Origin of archosaurian integumentary appendages: The bristles of the wild turkey beard express feather-type ? keratins

✍ Scribed by Sawyer, Roger H. ;Washington, Lynette D. ;Salvatore, Brian A. ;Glenn, Travis C. ;Knapp, Loren W.

• Book ID: 102339492
• Publisher: John Wiley and Sons
• Year: 2003
• Tongue: English
• Weight: 153 KB
• Volume: 297B
• Category: Article
• ISSN: 0022-104X
• DOI: 10.1002/jez.b.17

✦ Synopsis

Abstract

The discovery that structurally unique “filamentous integumentary appendages” are associated with several different non‐avian dinosaurs continues to stimulate the development of models to explain the evolutionary origin of feathers. Taking the phylogenetic relationships of the non‐avian dinosaurs into consideration, some models propose that the “filamentous integumentary appendages” represent intermediate stages in the sequential evolution of feathers. Here we present observations on a unique integumentary structure, the bristle of the wild turkey beard, and suggest that this non‐feather appendage provides another explanation for some of the “filamentous integumentary appendages.” Unlike feathers, beard bristles grow continuously from finger‐like outgrows of the integument lacking follicles. We find that these beard bristles, which show simple branching, are hollow, distally, and express the feather‐type β keratins. The significance of these observations to explanations for the evolution of archosaurian integumentary appendages is discussed. J. Exp. Zool. (Mol. Dev. Evol.) 297B: 27–34, 2003. © 2003 Wiley‐Liss, Inc.