Planoinnilla

Planoinnilla is a genus of extinct cartilaginous fish that lived during the Carboniferous period. Fossils of Planoinnilla have been found primarily in Europe and North America. This genus is characterized by its flattened body shape and relatively large pectoral fins, which likely aided in maneuvering close to the seafloor.

The diet of Planoinnilla is believed to have consisted of small invertebrates, such as crustaceans and mollusks. Its teeth were adapted for crushing rather than slicing, suggesting it preyed on hard-shelled organisms. The available fossil evidence indicates that Planoinnilla inhabited shallow marine environments.

Distinguishing features of Planoinnilla include the arrangement of its teeth and certain aspects of its cranial structure, though much remains to be understood about its precise taxonomic relationships. It is often grouped with other extinct sharks and rays, forming part of the diverse elasmobranch fauna of the Paleozoic era. Further research on newly discovered fossil material is crucial for a more complete understanding of Planoinnilla's biology and evolutionary history. The genus is considered significant for illustrating the diversity of early cartilaginous fishes.