Digital dissection and three-dimensional interactive models of limb musculature in the Australian estuarine crocodile (Crocodylus porosus)

Abstract

Digital dissection is a relatively new technique that has enabled scientists to gain a better understanding of vertebrate anatomy. It can be used to rapidly disseminate detailed, threedimensional information in an easily accessible manner that reduces the need for destructive, traditional dissections. Here we present the results of a digital dissection on the appendicular musculature of the Australian estuarine crocodile (<i>Crocodylus porosus</i>). A better understanding of this until now poorly known system in <i>C. porosus</i> is important, not only because it will expand research into crocodilian locomotion, but because of its potential to inform muscle reconstructions in dinosaur taxa. Muscles of the forelimb and hindlimb are described and three-dimensional interactive models are included based on CT and MRI scans as well as fresh-tissue dissections. Differences in the arrangement of musculature between <i>C. porosus</i> and other groups within the Crocodylia were found. In the forelimb, differences are restricted to a single tendon of origin for <i>triceps longus medialis</i>. For the hindlimb, a reduction in the number of heads of <i>ambiens</i> was noted as well as changes to the location of origin and insertion for <i>iliofibularis</i> and <i>gastrocnemius externus</i>.