Gross Anatomy of the Skeleton of Neonates of the Orinoco Matamata Turtle

01 Apr 20264 min read0 viewsJournal Feed

GIST

by Liliana Andrea Valencia-Flórez, Luz Natalia Franco-Montoya, Lynda J. Tamayo-Arango, Claudia P.

Ceballos The Orinoco Matamata turtle ( Chelus orinocensis ) was described in 2020, representing the second evolutionary lineage within the genus Chelus . The anatomy of this species has not been described, and such information is essential for understanding its biology, ecology, and for its potential relevance in clinical diagnosis.

This research provides the first description of the macroscopic morphology of the skeletal system in neonates of the Orinoco Matamata turtle. A group of confiscated turtles was donated from the Alexander von Humboldt institute to our university for academic purposes.

From this group, we obtained the skeleton of ten individuals, which measured between 51–80 mm of straight carapace length. Then, the skeletons of the two largest individuals were disarticulated to describe each bone in detail based on anatomical atlases and turtle osteological guides.

Bones from the cranium, mandible, hyoid apparatus, and the axial and appendicular skeletons were identified and photographed.

Clinical Editorial

Phylogenetic context and study aim

The study targets the macroscopic skeletal morphology of neonates, filling a gap in anatomical knowledge relevant to biology, ecology, and potential clinical relevance.

The Orinoco Matamata turtle (Chelus orinocensis) is identified as a distinct evolutionary lineage within Chelus, described in 2020.

Study design and specimen resources

Ten juvenile skeletons, ranging 51–80 mm in straight carapace length, were obtained from a confiscation and donated to the institution for academic study.
The two largest specimens were dissected to provide detailed, bone-by-bone descriptions using anatomical atlases and turtle osteology references.

Anatomical focus and methodology

The description encompasses bones of the cranium, mandible, hyoid apparatus, and both axial and appendicular skeletal components.
Bones were identified and photographed to document macroscopic morphology at this neonate stage.

Key findings and comparative context

orinocensis neonates were absent, incompletely ossified, or unusually well developed for this life stage.

When contrasted with other turtle species, certain bones in C.
These patterns are interpreted as potentially reflective of ecological adaptations specific to this species’ early ontogeny.

Limitations and future directions

The authors note that additional ontogenetic studies on skeletal ossification are necessary to clarify evolutionary history and functional adaptations in Chelus orinocensis.

Practical relevance and uncertainties

The work provides foundational anatomical data for a recently described lineage, with acknowledged uncertainty regarding broader developmental trajectories and comparative ontogeny across related taxa.