Evaluating The Precocial-altricial Axis of Motor Skill at Birth in A Preterm Pig Model.

The pace of locomotor development is a critical component of lifetime evolutionary fitness. Developmental researchers often divide species into two broad categories based on functional competence at birth: precocial infants who can independently stand and locomote soon after birth versus altricial infants who are either incapable of independent movement or can only do so in a rudimentary manner. However, investigating the lower level neuromotor and biomechanical traits that account for perinatal variation in motor development is complicated by the lack of experimental control inherent to all comparative analyses.

Pump the brakes! The hindlimbs of three-toed sloths decelerate and support suspensory locomotion.

Modern tree sloths are one of few mammalian taxa for which quadrupedal suspension is obligatory. Sloth limb musculature is specialized for slow velocity, large force contractions that stabilize their body below branches and conserve energy during locomotion. However, it is unknown whether two- and three-toed sloths converge in their use of limb kinetics and if these patterns are comparable to how primates perform arboreal suspensory locomotion.

Developmental factors influencing bone strength in precocial mammals: An infant pig model.

Most vertebrates are precocial in locomotion, able to walk and run soon after birth. Precociality requires a bony skeleton of sufficient strength to resist mechanical loading during early locomotor efforts. The aim of this study was to use an animal model-the preterm infant pig-to investigate some of the proximate factors that might determine variation in bone strength in precocial animals.

Does a suspensory lifestyle result in increased tensile strength? Organ-level material properties of sloth limb bones.

The material composition of vertebrate connective tissue is highly conserved across taxa. Existing data suggest that the compressive and tensile strength of limb bones are very similar despite marked variation in limb posture and locomotor patterns. However, the material properties of limb bone tissue from suspensory taxa have not been formally evaluated.