The first description of the limb-bones of palorchestids

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A new study has looked into the limb morphology of the extinct Australian mammal group known as the palorchestids, known for their tapir-like skulls and large claws, for the first time. The study analyzed 60 fossil specimens of palorchestids from different geological ages in order to determine their function and study their evolution. Using limb proportions as a proxy for body size, the study found that palorchestids could reach larger sizes than previously thought, with the largest known species possibly weighing over 1,000 kilograms. The study also finds that their forelimbs were very muscular and likely well-adapted for grabbing or shaking at leaves and branches when foraging for food. In addition, the study found that the elbow joints of the largest palorchestids were immobile and fixed at roughly an 100 degree angle, in a manner unique among all known mammals, suggesting that the arms served as permanently flexed food-gathering tools. The study also suggests that they may have stood up on their hind limbs on occasion in order to free up the arms for foraging purposes. Here is a link to the paper describing this study.

Paper (open access!): https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0221824