Marmornectes
Encyclopedia
Marmornectes is an extinct genus
of pliosaurid known from the Bedfordshire
of United Kingdom
.
BEDFM
1999.201, articulate
d partial skeleton
which preserved the skull
. It was collected in 1999 from the Sigaloceras enodatum ammonoid subzone, of the Peterborough Member, Oxford Clay Formation, dating to the early Callovian
stage of the late Middle Jurassic
, about 164.7-163.5 million years ago. It was found in the monotypic locality of Quest Pit, east of Stewartby.
It was a longirostrine pliosaurid with seven autapomorphies
which is most similar to Peloneustes philarchus. Nevertheless, a cladistic analysis found it to be basal to Peloneustes and other pliosaurids. An undescribed pliosaurid, NHMUK
R2439, found to be the sister taxon of this genus.
and the type species
is Marmornectes candrewi. The generic name is derived from marmor, Latin
for "marble", and nectes, Greek
for "swimmer", thus the meaning is "marble-swimmer". The specific name honors Chris Andrew for finding the only known specimen and donating it to Bedford Museum
in 1998.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of pliosaurid known from the Bedfordshire
Bedfordshire
Bedfordshire is a ceremonial county of historic origin in England that forms part of the East of England region.It borders Cambridgeshire to the north-east, Northamptonshire to the north, Buckinghamshire to the west and Hertfordshire to the south-east....
of United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
.
Description
Marmornectes is known from the holotypeHolotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
BEDFM
Bedford Museum
Cecil Higgins Art Gallery & Bedford Museum is the principal art gallery and museum in Bedford, Bedfordshire, England, run by Bedford Borough Council and the Trustees of the Cecil Higgins Collection.- Overview :...
1999.201, articulate
Articulate
Articulate may refer to:*Articulate *Articulate sign*Articulate sound*Joint, also known as articulation*Word modified by an article...
d partial skeleton
Skeleton
The skeleton is the body part that forms the supporting structure of an organism. There are two different skeletal types: the exoskeleton, which is the stable outer shell of an organism, and the endoskeleton, which forms the support structure inside the body.In a figurative sense, skeleton can...
which preserved the skull
Skull
The skull is a bony structure in the head of many animals that supports the structures of the face and forms a cavity for the brain.The skull is composed of two parts: the cranium and the mandible. A skull without a mandible is only a cranium. Animals that have skulls are called craniates...
. It was collected in 1999 from the Sigaloceras enodatum ammonoid subzone, of the Peterborough Member, Oxford Clay Formation, dating to the early Callovian
Callovian
In the geologic timescale, the Callovian is an age or stage in the Middle Jurassic, lasting between 164.7 ± 4.0 Ma and 161.2 ± 4.0 Ma. It is the last stage of the Middle Jurassic, following the Bathonian and preceding the Oxfordian....
stage of the late Middle Jurassic
Middle Jurassic
The Middle Jurassic is the second epoch of the Jurassic Period. It lasted from 176-161 million years ago. In European lithostratigraphy, rocks of this Middle Jurassic age are called the Dogger....
, about 164.7-163.5 million years ago. It was found in the monotypic locality of Quest Pit, east of Stewartby.
It was a longirostrine pliosaurid with seven autapomorphies
Autapomorphy
In cladistics, an autapomorphy is a distinctive anatomical feature, known as a derived trait, that is unique to a given terminal group. That is, it is found only in one member of a clade, but not found in any others or outgroup taxa, not even those most closely related to the group...
which is most similar to Peloneustes philarchus. Nevertheless, a cladistic analysis found it to be basal to Peloneustes and other pliosaurids. An undescribed pliosaurid, NHMUK
Natural History Museum
The Natural History Museum is one of three large museums on Exhibition Road, South Kensington, London, England . Its main frontage is on Cromwell Road...
R2439, found to be the sister taxon of this genus.
Etymology
Marmornectes was first named by Hilary F. Ketchum and Roger B. J. Benson in 20112011 in paleontology
-Lobopods:-Arachnids:-Insects:-Newly named jawless vertebrates:-Newly named acanthodian:-Newly named cartilaginous fishes:-Newly named bony fishes:-Newly named lepospondyls:-Newly named temnospondyls:-Newly named lissamphibians:...
and the type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
is Marmornectes candrewi. The generic name is derived from marmor, Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
for "marble", and nectes, Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
for "swimmer", thus the meaning is "marble-swimmer". The specific name honors Chris Andrew for finding the only known specimen and donating it to Bedford Museum
Bedford Museum
Cecil Higgins Art Gallery & Bedford Museum is the principal art gallery and museum in Bedford, Bedfordshire, England, run by Bedford Borough Council and the Trustees of the Cecil Higgins Collection.- Overview :...
in 1998.