Birds feature a complex soft-tissue structure in the lumbosacral region of the spinal cord. Tissue with potential mechanoreceptive function points at an intra-spinal mechanoreceptor that would be unique in higher vertebrates.
Evidence suggests that birds possess a novel sensing organ in the spinal canal; the `lumbosacral organ' (LSO), which may contribute to their locomotor agility and wide evolutionary success. Parts of the LSO soft tissue structure are visible with the naked eye, and already researchers in the19th century speculated about its function. We map the LSO morphology with traditional and new scientific methods; we hypothesize that intra-spinal mechanoreception could enable almost instantaneous acceleration sensing in locomoting birds.
