''Protobalistum imperiale'' is an extinct prehistoric
tetraodontid bony fish
Osteichthyes ( ; ), also known as osteichthyans or commonly referred to as the bony fish, is a Biodiversity, diverse clade of vertebrate animals that have endoskeletons primarily composed of bone tissue. They can be contrasted with the Chondricht ...
that lived from the
Lutetian
The Lutetian is, in the geologic timescale, a stage (stratigraphy), stage or age (geology), age in the Eocene. It spans the time between . The Lutetian is preceded by the Ypresian and is followed by the Bartonian. Together with the Bartonian it ...
epoch
In chronology and periodization, an epoch or reference epoch is an instant in time chosen as the origin of a particular calendar era. The "epoch" serves as a reference point from which time is measured.
The moment of epoch is usually decided b ...
of
Eocene
The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...
Monte Bolca
Monte Bolca is an Ypresian, Early Eocene-aged geologic site located near Verona, Italy, Verona, Italy. A ''Konservat-Lagerstätte'', it contains an extremely well-preserved and diverse marine biota, including the most diverse fish fauna of any Ce ...
.
In life, it would have resembled a compressed boxfish with five massive 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 closely related species or populations are considered sympatric when they exist in the same geographic area and thus frequently encounter each other. An initially interbreeding population that splits into two or more distinct spe ...
relative, ''
Spinacanthus
''Spinacanthus cuneiformis'' is an extinct prehistoric tetraodontid bony fish that lived from the Lutetian epoch of Eocene Monte Bolca.
In life, it would have resembled a somewhat-flattened boxfish with five long spines along the anterior-dorsa ...
'', in that its scales are large, and form a sort of armor. (In ''S. cuneiformis'', the individual scales are relatively small, and do not touch each other).
''Protobalistum imperiale'' and ''Spinacanthus'' were a part of the ecosystem of the lagoon that would become Monte Bolca. It has been suggested that, because of their similarity to
boxfish
Ostraciidae or Ostraciontidae is a family of squared, Actinopterygii, bony fish belonging to the order Tetraodontiformes, closely related to the pufferfishes and filefishes. Fish in the family are known variously as boxfishes, cofferfishes, cowfi ...
, and due to their close relation to modern-day
triggerfish
Triggerfish are about 40 species of often brightly colored marine ray-finned fishes belonging to the family Balistidae. Often marked by lines and spots, they inhabit tropical and subtropical oceans throughout the world, with the greatest speci ...
, spinacanthids may have preyed on shellfish and small fish.
See also
* ''
Spinacanthus
''Spinacanthus cuneiformis'' is an extinct prehistoric tetraodontid bony fish that lived from the Lutetian epoch of Eocene Monte Bolca.
In life, it would have resembled a somewhat-flattened boxfish with five long spines along the anterior-dorsa ...
'', its closest relative, lived
sympatrically with ''Protobalistum''
* ''
Eospinus
''Eospinus'' ("dawn spine") is an extinct genus of bizarre marine tetraodontiform fish from the Eocene. It is known from the earliest Ypresian-aged Danata Formation lagerstatten of Turkmenistan. The species name honors paleoichthyologist Pavel ...
'', another close relative from the Earliest Eocene of
Turkmenistan
Turkmenistan is a landlocked country in Central Asia bordered by Kazakhstan to the northwest, Uzbekistan to the north, east and northeast, Afghanistan to the southeast, Iran to the south and southwest and the Caspian Sea to the west. Ash ...
* ''
Eolactoria
''Eolactoria'' ("dawn '' Lactoria''") is an extinct genus of highly unusual prehistoric boxfish from the Eocene. It contains a single species, ''E. sorbinii'' from the Ypresian-aged Monte Bolca site in Italy.
It had two pairs of long spines, ...
'', another extinct tetraodontid from Monte Bolca
* ''
Proaracana
''Proaracana dubia'' is an extinct, prehistoric aracanid boxfish that lived during the Lutetian of middle Eocene Monte Bolca.
See also
* ''Eolactoria''
* Prehistoric fish
* List of prehistoric bony fish
This list of prehistoric bony fish is ...
'', another extinct tetraodontid from Monte Bolca
*
Prehistoric fish
__NOTOC__
Prehistoric fish are early fish that are known only from fossil records. They are the earliest known vertebrates, and include the first and extinct fish that lived through the Cambrian to the Quaternary. The study of prehistoric fish is ...
*
List of prehistoric bony fish
This list of prehistoric bony fish is an attempt to create a comprehensive listing of all Genus, genera from the fossil record that have ever been considered to be bony fish (class Osteichthyes), excluding purely vernacular terms. The list includ ...
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
{{paleo-tetraodontiformes-stub