''Eotetraodon'' ("dawn ''

Tetraodon ''Tetraodon'' is a genus in the pufferfish family (Tetraodontidae) found in freshwater in Africa. It is the type genus of the family and historically included numerous other species; several Asian species were moved to the genera '' Dichotomycter ...

''") is an extinct genus of miniature prehistoric

pufferfish Tetraodontidae is a family of marine and freshwater fish in the order Tetraodontiformes. The family includes many familiar species variously called pufferfish, puffers, balloonfish, blowfish, blowers, blowies, bubblefish, globefish, swellfis ...

that lived in Europe from the early to mid-late

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 ...

. It is the earliest pufferfish known from fossil remains. The following species are known: * †''E. gornylutshensis'' Bannikov & Tyler, 2008 - mid-late Eocene (

Bartonian The Bartonian is, in the International Commission on Stratigraphy's (ICS) geologic time scale, a stage or age in the middle of the Eocene Epoch or Series. The Bartonian Age spans the time between . It is preceded by the Lutetian and is follow ...

) of the

North Caucasus The North Caucasus, or Ciscaucasia, is a subregion in Eastern Europe governed by Russia. It constitutes the northern part of the wider Caucasus region, which separates Europe and Asia. The North Caucasus is bordered by the Sea of Azov and the B ...

, Russia ( Kuma Formation) * †''E. pygmaeus'' (de Zigno, 1887) (

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

) -

early Eocene In the geologic timescale the Ypresian is the oldest age (geology), age or lowest stage (stratigraphy), stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by th ...

of Italy (

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 ...

lagerstatten) * †''E. tavernei'' Tyler & Bannikov, 2012 - early Eocene of Italy (Monte Bolca lagerstatten) As the name of the type species suggests, ''Eotetraodon'' was a very small fish that (depending on the species) reached only . Despite this very small size, fossil specimens are fully ossified, suggesting that they are of adult individuals. Although generally considered an early pufferfish, some recent studies have placed it as part of an

evolutionary grade A grade is a taxon united by a level of morphological or physiological complexity. The term was coined by British biologist Julian Huxley, to contrast with clade, a strictly phylogenetic unit. Phylogenetics The concept of evolutionary grades ...

, containing several other Bolca tetraodontiforms, leading to the threetooth puffer (''Triodon''), a different tetraodontiform fish.

References

Tetraodontidae Prehistoric percomorph genera Ypresian genus first appearances Bartonian genus extinctions Eocene fish of Europe Fossils of Italy Fossils of Russia Taxa named by James C. Tyler Fossil taxa described in 1980 {{paleo-tetraodontiformes-stub