Pachycormus

Pachycormus
	Pachycormus bollensis
Temporal occurrence
	Lower Jurassic
	182.7 to 174.1 million years
Locations
	Central Europe; England; Italy;
Systematics
Superclass :	Jaw mouths (Gnathostomata)
Class :	Ray fins (Actinopterygii)
Subclass :	Neuflosser (Neopterygii)
Order :	Pachycormiformes
Family :	Pachycormidae
Genre :	Pachycormus
Scientific name
	Pachycormus
	Agassiz , 1833

Pachycormus is a genus of extinct marine bony fish from the Lower Jurassic of Europe. Louis Agassiz establishes the genus in 1833. It is the type of the family Pachycormidae .

features

Pachycormus belongs to the Pachycormiformes, an extinct order of the ray fins (Actinopterygii). Its body is spindle-shaped and robust. Further features are the absence of the pelvic fins and the position of the unpaired fins (the dorsal fin lies completely in front of the anal fin). On the front part of the skull there is a concise fronto parietal bulge. Pachycormus could reach a length of over a meter.

Way of life

Due to the densely toothed, individual row of teeth and the needle-like small teeth, it is assumed that Pachycormus ate fish . Even cephalopods part of his diet. A strong homocercial caudal fin enabled it to swim quickly in deep waters.

Systematics

Pachycormus belongs to the family of the Pachycormidae and thus to the bony fish (Osteichthyes), but not to the real bony fish (Teleostei).

List of known species

Pachycormus acutirostris (Agassiz, 1844)
Pachycormus bollensis ( Quenstedt , 1858)
Pachycormus curtus (Agassiz, 1843)
Pachycormus elongatus (Sauvage, 1875)
Pachycormus intermedius (Agassiz, 1844)
Pachycormus macropterus ( De Blainville , 1818)

literature

Pachycormus curtus , collection number SMNS 55300

PH Lambers: On the Ichthyofauna of the Solnhofen Lithographic Limestone (Upper Jurassic, Germany). Rijksuniversiteit Groningen, 1992, OCLC 311805060 .
M. Lindkvist: A Phylogenetic Appraisal of Pachycormus bollensis: Implications for Pachycormiform Evolution. Uppsala universitet, Institutions for Geovetenskaper Candidate Examination i Geovetenskap, 2012. (diva-portal.org)
AJ Mainwaring: Anatomical and systematic review of the Pachycormidae, a family of Mesozoic fossil fishes. University of London, 1978, OCLC 500512214 , p. 87.
AS Woodward: Catalog of the fossil fishes in the British Museum (Natural History), Cromwell Road, SW Part III. Containing the Actinopterygian teleostomi of the orders Chondrostei (concluded), Protospondyli, Aetheospondyli, and Isospondyli (in part). Family Pachycormidae. 1895, OCLC 769911406 , p. 385.

Individual evidence

↑ ^a ^b ^c P. Lambers: On the Ichthyofauna of the Solnhofen Lithographic Limestone (Upper Jurassic, Germany). Rijksuniversiteit Groningen, 1992, p. 233, p. 235.
↑ JP Lehman: Traité de Paléontologie Tome IV en trois volumes - L'Origine des Vertébrés leur expansion dans les eaux douces et le milieu marin - Actinoptérygiens, Crossoptérygiens, Dipneustes , 1966, p. 150.
Jump up ↑ AJ Mainwaring: Anatomical and systematic review of the Pachycormidae, a family of Mesozoic fossil fishes. 1978, p. 87.
↑ M. Lindkvist: A Phylogenetic Appraisal of Pachycormus bollensis: Implications for Pachycormiform Evolution. Uppsala universitet, Institutions for Geovetenskaper Candidate Examination i Geovetenskap, 2012, p. 1.

[Lambers-1] P. Lambers: On the Ichthyofauna of the Solnhofen Lithographic Limestone (Upper Jurassic, Germany). Rijksuniversiteit Groningen, 1992, p. 233, p. 235.

[2] JP Lehman: Traité de Paléontologie Tome IV en trois volumes - L'Origine des Vertébrés leur expansion dans les eaux douces et le milieu marin - Actinoptérygiens, Crossoptérygiens, Dipneustes , 1966, p. 150.

[3] Jump up ↑ AJ Mainwaring: Anatomical and systematic review of the Pachycormidae, a family of Mesozoic fossil fishes. 1978, p. 87.

[4] M. Lindkvist: A Phylogenetic Appraisal of Pachycormus bollensis: Implications for Pachycormiform Evolution. Uppsala universitet, Institutions for Geovetenskaper Candidate Examination i Geovetenskap, 2012, p. 1.