Evidence suggests that birds possess an enigmatic balance sensing organ in the lumbosacral spinal canal, called the ‘lumbosacral organ’ (LSO).  We develop a 3D anatomical model of the quail LSO that includes bony and soft-tissue structures. Based on anatomical features, we propose that the LSO functions as a fluid-submerged mass-spring-damper system that could sense accelerations based on strain in the ligamentous network supporting the spinal cord.

Viktoriia Kamska, Monica A Daley, Alexander Badri-Spröwitz, 3D anatomy of the quail lumbosacral spinal canal—implications for putative mechanosensory function, Integrative Organismal Biology, obaa037, https://doi.org/10.1093/iob/obaa037