Hindeodus parvus
- 演化之聲
- Mar 21
- 2 min read
Age
Triassic（Induan）
252.2–251.2 Ma
Taxonomy
Kingdom: Animalia
Phylum: Chordata
Class: Conodonta
Order: Ozarkodinida
Family: Anchignathodontidae
Genus: Hindeodus
Species: Hindeodus parvus
Morphological description
Hindeodus parvus is a conodont animal whose feeding apparatus is composed of multiple tooth-like elements. Fossil evidence reveals six element types, totaling approximately 15 elements arranged in bilateral symmetry, including positions P1, P2, M, S0, and S1–S4. All of these elements are less than 1 mm in size.
The P1 element bears a distinctly enlarged distal denticle, with one denticle approximately twice the height of the others. The P2 element possesses a long and robust cusp, a short anterior process, and an elongated posterior process bearing multiple denticles, with a slight distal twist. The M element has a slender cusp and asymmetrical lateral processes.
The S0 element is a symmetrical alate structure lacking a posterior process, with short and high lateral processes. The S1–S2 elements have robust cusps and both inner and outer lateral processes; the outer lateral process is twisted, causing its posterior surface to face upward. The S3–S4 elements are characterized by slender cusps, elongated posterior processes, and shorter anterior processes bearing a terminal denticle.
Etymology
The species Hindeodus parvus was originally described as Anchignathodus parvus, but was later reassigned to the genus Hindeodus following taxonomic revision.
The genus name Hindeodus honors the paleontologist George Jennings Hinde, known for his work on conodonts.
The species name parvus is derived from Latin, meaning "small".
Biological description
Hindeodus parvus lived in the earliest Triassic and belongs to the conodont animals. Its fossils are primarily found in siliceous claystones of the Hashikadani Formation within the Mino Terrane of Japan.
Many of the processes on its elements exhibit clear directionality: some extend anteriorly, while others project toward the posterior. This organization suggests that the feeding apparatus was adapted for grasping, securing, and guiding food during feeding.
The genus Hindeodus spans a long stratigraphic range and underwent rapid diversification from the late Permian to the early Triassic. Hindeodus parvus is one of the key representative species of this interval. Because of the diagnostic morphology of its P1 element, it plays an important role in biostratigraphy across the Permian–Triassic boundary and is commonly used as an index species for defining this geological boundary.
The prevailing interpretation of conodont ecology suggests that these animals functioned as micro-predators.
（Author: Shui-Ye You）
References
Agematsu S et al. (2017). Reconstruction of the multielement apparatus of the earliest Triassic conodont, Hindeodus parvus, using synchrotron radiation X-ray micro-tomography. Journal of Paleontology.
Zhang M et al. (2017). Testing hypotheses of element loss and instability in the apparatus composition of complex conodonts: articulated skeletons of Hindeodus. Paleontology.
35.47, 136.92
Comments