''Eothyrsites'' ("dawn ''

Thyrsites ''Thyrsites atun'' ( Euphrasén, 1791), known as the snoek in South Africa and as the barracouta in Australasia, is a long, thin species of snake mackerel found in the seas of the Southern Hemisphere, and a popular food fish in South Africa, pa ...

''") is an extinct genus of prehistoric snake mackerel from the

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 contains a single species, ''E. holosquamatus'' from the mid-late Eocene (late

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 ...

or early

Priabonian The Priabonian is, in the ICS's geologic timescale, the latest age or the upper stage of the Eocene Epoch or Series. It spans the time between . The Priabonian is preceded by the Bartonian and is followed by the Rupelian, the lowest stage ...

)-aged Burside Mudstone Formation of the

South Island The South Island ( , 'the waters of Pounamu, Greenstone') is the largest of the three major islands of New Zealand by surface area, the others being the smaller but more populous North Island and Stewart Island. It is bordered to the north by ...

, New Zealand. It is one of the few Eocene-aged marine fishes from New Zealand known from a relatively complete skeleton. It was described by Frederick Chapman on the basis of a partial skeleton, but other fragments have also been recovered from the same site, all of which likely belong to the same individual as the

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

. Analysis of the skeleton suggests that it is most closely related to the "gemfish"-type gempylids such as '' Rexea'' and '' Promethichthys''. ''Eothyrsites'' was likely an

epipelagic The photic zone (or euphotic zone, epipelagic zone, or sunlight zone) is the uppermost layer of a body of water that receives sunlight, allowing phytoplankton to perform photosynthesis. It undergoes a series of physical, chemical, and biological ...

predatory genus, similar to modern members of the group. Its presence in New Zealand during the Late Eocene suggests that the gempylids must have colonized the southern Pacific from their region of origin in the northern

Tethys Ocean The Tethys Ocean ( ; ), also called the Tethys Sea or the Neo-Tethys, was a prehistoric ocean during much of the Mesozoic Era and early-mid Cenozoic Era. It was the predecessor to the modern Indian Ocean, the Mediterranean Sea, and the Eurasia ...

by this point.

References

Prehistoric percomorph genera Monotypic prehistoric ray-finned fish genera {{paleo-perciformes-stub

† A dagger, obelisk, or obelus is a typographical mark that usually indicates a footnote if an asterisk has already been used. The symbol is also used to indicate death (of people) or extinction (of species or languages). It is one of the mo ...

Bartonian genera Priabonian genus extinctions Cenozoic fish of Oceania Fossils of New Zealand Eocene fish Fossil taxa described in 1934

See also

References