''Spinacanthus cuneiformis'' is an extinct prehistoric tetraodontid

bony fish Osteichthyes (), popularly referred to as the bony fish, is a diverse superclass of fish that have skeletons primarily composed of bone tissue. They can be contrasted with the Chondrichthyes, which have skeletons primarily composed of cartilag ...

that lived from the Lutetian epoch of Eocene

Monte Bolca Monte Bolca is a lagerstätte near Verona, Italy that was one of the first fossil sites with high quality preservation known to Europeans, and is still an important source of fossils from the Eocene. Geology Monte Bolca was uplifted from the T ...

. In life, it would have resembled a somewhat-flattened boxfish with five long spines along the anterior-dorsal side, with the longest spine directly above the forehead, and the shortest spine directly in front of the dorsal fin. It is distinguished from its close,

sympatric In biology, two related species or populations are considered sympatric when they exist in the same geographic area and thus frequently encounter one another. An initially interbreeding population that splits into two or more distinct species sh ...

relative, '' Protobalistum'', in that its individual scales are relatively small, and do not touch each other. (In ''Protobalistum'', the scales are large, and form a sort of armor). ''S. cuneiformis'' and ''Protobalistum'' were a part of the ecosystem of the lagoon that became Monte Bolca. Because of their similarity to boxfish, and due to their close relation to modern-day triggerfish, spinacanthids may have preyed on shellfish and small fish.

References

A remarkable new genus of Tetraodontiform fish with features of both Balistids and Ostraciids from the Eocene of Turkmenistan
(contains a brief discussion and description of Spinacanthidae) Spinacanthidae Fossils of Italy Fossil taxa described in 1835 {{paleo-rayfinned-fish-stub

See also

References