''Orthocormus'' is an extinct genus of prehistoric
pachycormiform bony fish.
It is known from three species found in Late
Jurassic
The Jurassic ( ) is a geologic period and stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of ...
(
Kimmeridgian
In the geologic timescale, the Kimmeridgian is an age in the Late Jurassic Epoch and a stage in the Upper Jurassic Series. It spans the time between 157.3 ± 1.0 Ma and 152.1 ± 0.9 Ma (million years ago). The Kimmeridgian follows the Oxford ...
) aged
plattenkalk
Plattenkalk is a very finely grained limestone chemically precipitated in a stratified water column under conditions where bioturbation does not occur. The reasons for the quiet depositional environment and the processes of sediment accumulation v ...
deposits in Bavaria, Germany.
The species "''
Hypsocormus" tenuirostris'' Woodward 1889 from the late
Middle Jurassic (
Callovian
In the geologic timescale, the Callovian is an age and stage in the Middle Jurassic, lasting between 166.1 ± 4.0 Ma (million years ago) and 163.5 ± 4.0 Ma. It is the last stage of the Middle Jurassic, following the Bathonian and preceding the ...
)
Oxford Clay
The Oxford Clay (or Oxford Clay Formation) is a Jurassic marine sedimentary rock formation underlying much of southeast England, from as far west as Dorset
Dorset ( ; archaically: Dorsetshire , ) is a county in South West England on the ...
is not closely related to the type species of ''Hypsocormus'', and is more closely related to ''Orthocormus'' + ''
Protosphyraena
''Protosphyraena'' is a fossil genus of swordfish-like marine fish, that thrived worldwide during the Upper Cretaceous Period (Coniacian-Maastrichtian). Though fossil remains of this taxon have been found in both Europe and Asia, it is perhaps b ...
'', and thus has sometimes been referred to in
open nomenclature
Open nomenclature is a vocabulary of partly informal terms and signs in which a taxonomist may express remarks about their own material. This is in contrast to synonymy lists, in which a taxonomist may express remarks on the work of others. Common ...
as ''Orthocormus? tenuirostris.
''
See also
*
Prehistoric fish
The evolution of fish began about 530 million years ago during the Cambrian explosion. It was during this time that the early chordates developed the skull and the vertebral column, leading to the first craniates and vertebrates. The first fis ...
*
List of prehistoric bony fish
References
External links
*
Pachycormiformes
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