marginal cusps. Skeleton Both the scapula and humerus are slender in appearance. The scapula has a narrow scapular base and a scapular spine that may have been directed towards the glenoid. The humerus has a deltopectoral crest that extends less than half the length of the shaft. The radial condyle of the humerus is poorly developed, while the olecranon process of the ulna is moderately developed. The manus is short. Xu et al. (2001) originally recorded the manual phalangeal formula as 2-3-3-2. However, Ji et al. (2016) noted the presence of five digits (fingers) rather than four in one specimen of Liaoningosaurus. The femur has an indistinct femoral head and a crest-shaped trochanter present on the mid-length of the shaft. The tibia is as long as the femur. The pes (foot) is about 230% as long as the manus. Metatarsals II–IV are elongate, while metatarsals I and V are splint-like. The pedal phalangeal formula is 0-3-4-5-0. Both the pedal and manual unguals are triangular in dorsal view, a condition also seen in Dyoplosaurus. Xu et al. (2001) noted that the sternum has a sub-trapezoidal body, a very slender posterolateral process and a straight medial margin. However, Arbour & Currie (2015) questioned whether or not the sternum was preserved. The bone, tentatively identified as the left sternum, was found adjacent to various other elements and its boundaries remain unclear. The sternum could have possibly been displaced post-mortem, resulting in the anteriorly pointing posterolateral process. The sternum is dissimilar to those of other ankylosaurs, as it is not paddle-like with ovoid medial ends that narrow posterolaterally like that of nodosaurids, or fused at the midline to form a diamond shape, with narrower posterolaterally directed processes like that of ankylosaurids. The preacetabular process of the ilium deflects laterally and is enlarged. A crest is present on the acetabulum, which connects the ischial and pubic peduncles. The ischium is straight with a convex acetabular margin, while the pubis is strongly reduced in size. Liaoningosaurus represents the oldest ankylosaurid known to have had a tail club. Although it possessed a tail club handle, it does not appear that a tail club knob was present. The tail club in ankylosaurids refers to the entire distal structure of the ankylosaurid tail, rather than just the large terminal osteoderms. The handle consists of interlocking neural arches on the distal caudal vertebrae, and prezygapophyses that overlap with the adjacent