Abstract - The middle Miocene Rubielos de Mora Konservat-Lagerstätte of northeast Spain is
hosted within profundal, finely laminated, lacustrine mudstones. The diverse biota
includes abundant salamanders. Most individuals died during separate episodes and
sank rapidly postmortem. Specimens are typically preserved in dorso-ventral aspect, the
most hydrodynamically stable orientation. The near-cylindrical morphology of the
body, however, allowed some carcasses to settle in or subsequently re-orientate into, lateral
orientations. Loss of skeletal elements (i.e. reduced completeness) reflects their location
within the body and followed a distal to proximal trend. Two stages are identified:
initial loss of a small number of phalanges, followed by loss of more proximal limb
bones plus additional phalanges. Disarticulation is more complex: it occurred via several
mechanisms (notably, abdominal rupture and re-orientation of part of the body and
limbs during decay) and shows no consistent pattern among specimens. The physical
taphonomy of the salamanders is controlled predominantly by intrinsic biological factors,
i.e. the geometry of the body and of individual skeletal elements, the orientation,
inherent strength and location of specific joints and the extent to which soft tissues,
particularly the skin, persist during decay. These biological factors probably control
patterns of physical taphonomy of other fossil tetrapods with a similar skeletal
configuration.
Lethaia, 45, 210-226, 2012.