|
Polyipnus Laruei
''Polyipnus'' is a genus of oceanic ray-finned fish in the family (biology), family Sternoptychidae. This is the largest genus of the marine hatchetfishes subfamily (biology), subfamily Sternoptychinae and indeed of the entire Sternoptychidae. It is not quite as apomorphic as their relatives; it may be that the genus is actually a paraphyletic assemblage of less advanced Sternoptychinae and would need to be split. Fossils of this genus show that they have existed at least since the Early Oligocene, about 30 million years ago. Species There are currently 34 recognized species in this genus: * ''Polyipnus aquavitus'' Ronald Clay Baird, R. C. Baird, 1971 (aquavit hatchetfish) * ''Polyipnus asper'' Antony S. Harold, Harold, 1994 * ''Polyipnus asteroides'' Leonard Peter Schultz, L. P. Schultz, 1938 * ''Polyipnus bruuni'' Antony S. Harold, Harold, 1994 * ''Polyipnus clarus'' Antony S. Harold, Harold, 1994 (slope hatchetfish) * ''Polyipnus danae'' Antony S. Harold, Harold, 1990 * ''Poly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligocene
The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the exact dates of the start and end of the epoch are slightly uncertain. The name Oligocene was coined in 1854 by the German paleontologist Heinrich Ernst Beyrich from his studies of marine beds in Belgium and Germany. The name comes from Ancient Greek (''olígos'') 'few' and (''kainós'') 'new', and refers to the sparsity of Neontology, extant forms of Mollusca, molluscs. The Oligocene is preceded by the Eocene Epoch and is followed by the Miocene Epoch. The Oligocene is the third and final epoch of the Paleogene Period. The Oligocene is often considered an important time of transition, a link between the archaic world of the tropical Eocene and the more modern ecosystems of the Miocene. Major chang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
