Hemitrichas

from Wikipedia, the free encyclopedia
Hemitrichas
Temporal occurrence
Upper Eocene to Lower Miocene
38 to 15.97 million years
Locations
  • Europe (Germany, France)
Systematics
Perch relatives (Percomorphaceae)
Ovalentaria
Superordinate : Earfish relatives (Atherinomorphae)
Order : Earfish (Atheriniformes)
Family : Old world earfish (Atherinidae)
Genre : Hemitrichas
Scientific name
Hemitrichas
Peters , 1877

Hemitrichas is an extinct genus of smaller, slender earfish from the recent family of Atherinidae . The species of the genus Hemitrichas found so farwere distributed from the Eocene to the Miocene and are therefore the oldest documented fossils of this fish family.

Some of the individual species of the genus are fossilized, some are only otoliths (“stones” of a sensory organ located in the inner ear of the fish), and some are both. All fish were found in brackish or freshwater sediments, with the exception of H. stapfi , which came from a seawater environment (from a 190 cm thick clay-marl sequence at the base of the upper cerithia layers in a quarry near Oppenheim in the Mainz basin) .

Several species are found in the Mainz Basin and Hanau Basin , other species come from France. In the Mainz and Hanau basins, the species of the genus Hemitrichas are widespread in the euryhaline sediments of the late Oligocene and early Miocene. They are usually the only fish species, but there are numerous specimens. There are other sites in Switzerland and Iran.

Systematics and types

Because otoliths are often only present, some species of the genus Hemitrichas from western Paratethys , a geological marginal sea of ​​Eurasia, were initially described as Palaeoatherina Gaudant, 1976 or Atherina Linnaeus, 1758 .

The following species are classified in the genus:

  • Hemitrichas bartensteini (Malz, 1978) from the lower Miocene
  • Hemitrichas bergeri Reichenbacher, 1992 from the late Oligocene
  • Hemitrichas britannica Gaudant, 1989 from the Oligocene
  • Hemitrichas denisae Reichenbacher, 2004 from the early Miocene
  • Hemitrichas dentifera Stinton & Kissling, 1968 from the late Oligocene
  • Hemitrichas formosa Gaudant from the late Eocene
  • Hemitrichas giraudi (Piton, 1936) from the Upper Oligocene or Lower Miocene
  • Hemitrichas martinii Reichenbacher, 1993 from the late Ottnangian or early Carpathian
  • Hemitrichas miocenica (Hamlet, 1942) from the Lower Miocene
  • Hemitrichas molassica Reichenbacher, 1993 from the late Ottnangian
  • Hemitrichas rotunda (hamlet, 1963) from the lower Miocene
  • Hemitrichas schaeferi Reichenbacher, 2000 from the late Oligocene
  • Hemitrichas schisticola Peters, 1877 ( type specimen )
  • Hemitrichas stapfi Gaudant & Reichenbacher, 2005 from the Upper Oligocene
  • Hemitrichas schwarzhansi Reichenbacher, 1993 from the late Ottnangian
  • Hemitrichas vardinis Sauvage 1883 from the Upper Eocene / earliest Oligocene

literature

  • Bettina Reichenbacher : A partly endemic euryhaline fish fauna (otoliths, teeth) from the Early Miocene of the Aix-Basin (Provence, southern France) . In: Cour. Research Inst. Senckenberg . tape 246 , 2004, pp. 113-127 . ( pdf )
  • Jean Gaudant & Bettina Reichenbacher: Hemitrichas stapfi n. Sp. (Teleostei, Atherinidae) with otoliths in situ from the late Oligocene of the Mainz Basin . In: Zitteliana . A 45, 2005, ISSN  1612-412X , p. 189-198 . ( pdf )
  • J. Jost, D. Kälin, T. Schulz-Mirbach: Late Early Miocene lake deposits near Mauensee, central Switzerland: fish fauna (otoliths, teeth), accompanying biota and palaeoecology . In: Eclogae Geologicae Helvetiae . tape 99 , no. 3 , 2006, p. 309-326 , doi : 10.1007 / s00015-006-1198-5 .
  • D. Campanella, LC Hughes, PJ Unmack, DD Bloom, KR Piller, G. Ortí: Multi-locus fossil-calibrated phylogeny of Atheriniformes (Teleostei, Ovalentaria). Molecular Phylogenetics and Evolution, March 2015, p. 10 DOI: 10.1016 / j.ympev.2015.03.001 .

Web links