Myological peculiarities in Rhinoderma darwinii (Anura: Rhinodermatidae)

Area of Science:

• Zoology
• Comparative Anatomy
• Herpetology

Background:

• Rhinoderma darwinii, a neotropical frog, belongs to the enigmatic and less diversified Rhinodermatidae family.
• Understanding the myology of R. darwinii is crucial for its taxonomic and evolutionary placement.

Purpose of the Study:

• To re-analyze the myology of Rhinoderma darwinii.
• To identify unique muscular structures and describe novel muscles within the species.
• To assess the utility of myological characters for future systematic and phylogenetic analyses of Rhinodermatidae.

Main Methods:

• Detailed anatomical dissection of Rhinoderma darwinii specimens.
• Comparative analysis of muscle structure, origin, and insertion points.
• Identification and description of previously unrecorded muscles.

Main Results:

• Fourteen muscles (m. deltoides scapularis, m. coracoradialis, m. coracobrachialis brevis, m. omohyoideus, m. cucularis, m. interhyoideus, m. levator mandibular posterior externus, m. levator mandibular posterior articularis, m. levator posterior longus, m. geniohyoideus lateralis, m. geniohyoideus medialis, m. intermaxillaris, m. iliofibularis and m. iliofemoralis) exhibit unique structural or attachment characteristics.
• An apical supplementary element of the m. intermandibularis is identified for the first time in R. darwinii.
• A novel muscle associated with the thigh skin is described for the first time in anurans.

Conclusions:

• The myology of Rhinoderma darwinii presents several unique and novel features.
• These myological characters hold significant potential for advancing systematic and phylogenetic studies within the Rhinodermatidae family.
• Further investigation into the myology of R. darwinii can illuminate the evolutionary history of this enigmatic group.