Pseudoasthenocormus

Pseudoasthenocormus Temporal range: Kimmeridgian-Tithonian ~152–148 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Fossil of Pseudoasthenocormus retrodorsalis
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	†Pachycormiformes
Family:	†Pachycormidae
Genus:	†Pseudoasthenocormus
Species:	†P. retrodorsalis
Binomial name
†Pseudoasthenocormus retrodorsalis (Eastman, 1914)

Pseudoasthenocormus is an extinct genus of ray-finned fish belonging to the family Pachycormidae. It contains one species, P. retrodorsalis. It lived during the upper Jurassic (Kimmeridgian–Tithonian, about 152–148 million years ago) and its fossil remains have been found in Germany.^[1][2]

Description

Large in size, this fish easily exceeded one metre in length. Like many other similar genera, Pseudoasthenocormus possessed a robust and compact body, although generally more slender than Asthenocormus. As indicated by the specific epithet, the dorsal fin is set back, originating just behind the anal, and is much shorter than the latter.^[2] The dorsal fin is composed of a few rays, which decrease in size posteriorly. The anal fin has become independent, with the rays (about 30) starting almost vertically from the haemal arches. The palate was equipped with small, slightly curved conical teeth. Along the anterior margin of the jaws were larger teeth with laterally compressed bases.^[1]

Etymology

The generic name is derived from Asthenocormus, and the specific epithet is after the Greek for "rear fin."^[2]

Classification

The first fossils of this animal, found in the famous Solnhofen deposit, were described in 1914 by Eastman, who attributed them to a new species of the genus Asthenocormus (A. retrodorsalis).^[2] It was only in 1999 that Lambers redescribed the species, attributing it to a separate genus (Pseudoasthenocormus).^[1]

This animal, as well as the related Asthenocormus, was a large representative of the family Pachycormidae, a group of bony fishes close to the origin of the teleosts and including some of the oldest filter-feeding fishes.^[1]

References

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Teleostei sensu de Pinna, 1996 (= Teleosteomorpha)

Kingdom: Animalia Phylum: Chordata Class: Actinopterygii Subclass: Neopterygii
Actinopterygii see Actinopterygii Neopterygii see Neopterygii Teleostei see below↓

Teleostei
Teleostei †Atacamichthys †Baleiichthys †Barschichthys †Bunoderma †Ceramurus †Dorsetichthys †Elpistoichthys †Eurycormus †Galkinia †Grimmenichthys †Hengnania †Hulettia? †Hungkiichthys †Ichthyokentema †Jialingichthys †Koonwarria †Ligulella †Luxembourgichthys †Majokia †Marcopoloichthys †Neobaleiichthys †Oligopleurus? †Pholidophorichthys †Pholidophoroides †Pholidophoropsis †Prohalecites †Ruedersdorfia †Seefeldia †Seinstedtia †Signeuxella †Pachycormidae Asthenocormus Australopachycormus Bonnerichthys Eugnathides? Euthynotus Germanostomus Haasichthys Hypsocormus Kaykay Leedsichthys Martillichthys Notodectes Ohmdenia Orthocormus Pachycormus Protosphyraena Pseudoasthenocormus Rhinconichthys Sauropsis Saurostomus Simocormus †Aspidorhynchidae Aspidorhynchus Belonostomus Jonoichthys Pseudovinctifer Richmondichthys Vinctifer †Pholidophoridae sensu stricto Annaichthys Ceneichthys Eopholidophorus Knerichthys Lombardichthys Malingichthys Parapholidophorus Pholidoctenus Pholidophoretes Pholidophorus Pholidorhynchodon Pseudopholidoctenus Zambellichthys †Archaeomaenidae Aphnelepis Archaeomaene Gurvanichthys Oreochima Wadeichthys Zaxilepis †Siyuichthyidae Bogdaichthys Dsungarichthys Manasichthys Siyuichthys Wukangia †Pleuropholidae Austropleuropholis Gondwanapleuropholis Parapleuropholis Pleuropholis Zurupleuropholis †Ankylophoridae Ankylophorus Lehmanophorus Neopholidophoropsis Pholidophoristion Siemensichthys Songaichthys Steurbautichthys †Catervariolidae Catervariolus Kisanganichthys Songanella Teleosts with cycloid scales see below↓ Otolith taxa †Archengraulis †Bicavolithus †Doggerichthys †Sphaeronchus †Xenoleptolepis

Teleosts with cycloid scales
Teleosts with cycloid scales †Antofagastaichthys †Araripichthys †Paraclupavus †Pholidolepis †Todiltia †Leptolepidae Leptolepis Longileptolepis Proleptolepis †Luisiellidae Cavenderichthys? Luisiella Waldmanichthys? †Ascalaboidae Ascalabos Ebertichthys Tharsis †Crossognathiformes Bavarichthys Chongichthys Salminops? Varasichthyidae? Bobbichthys Domeykos Luisichthys Protoclupea Varasichthys Notelopidae Bavarichthys? Michin? Notelops Nusaviichthys Crossognathidae Apsopelix Crossognathus Pachyrhizodontidae Apricenapiscis Aquilopiscis Cavinichthys Chongichthys? Elopopsis Goulmimichthys Greenwoodella Kradimus Lebrunichthys Michin? Motlayoichthys Nardopiscis Pachyrhizodus Platinx Polcynichthys Rhacolepis Stanhopeichthys Tingitanichthys †Ichthyodectiformes Africathrissops Allothrissops Altamuraichthys Antarctithrissops Ascalabothrissops? Capassoichthys Carsothrissops Dugaldia Faugichthys Furloichthys Garganoichthys Gillicus Occithrissops Ogunichthys Pachythrissops? Prymnetes Sultanuvaisia Thrissops Verraesichthys Chuhsiungichthyidae Chuhsiungichthys Jinjuichthys Mesoclupea Bardackichthyidae Amakusaichthys? Bardackichthys Heckelichthys? Cladocyclidae Aidachar Chirocentrites Chiromystus Cladocyclus Cladocynodon Eubiodectes Ichthyodectidae Cooyoo Ghrisichthys Ichthyodectes Postredectes Xiphactinus Saurodontidae Gwawinapterus Prosaurodon Saurocephalus Saurodon Unamichthys Vallecillichthys Crown-Teleostei see below↓

Crown-Teleostei
Elopomorpha see Elopomorpha †Orthogonikleithridae Cavenderichthys? Leptolepides Orthogonikleithrus Waldmanichthys? Osteoglossomorpha see Osteoglossomorpha †Tselfatiiformes Eoplethodus Protobramidae Abisaadichthys Eusebichthys Protobrama Plethodidae Bachea Bananogmius Concavotectum Dixonanogmius Enischnorhynchus Luxilites Martinichthys Moorevillia Niobrara Paranogmius Pentanogmius Plethodus Pseudonogmius Pseudothryptodus Rhamphoichthys Syntegmodus Thryptodus Tselfatia Zanclites Clupeocephala Otocephala Euteleostei