Name:
Regnosaurus
(Regni lizard - After a tribe that once inhabited Sussex,
England).
Phonetic: Reg-noe-sore-us.
Named By: Gideon Mantell - 1828.
Classification: Chordata, Reptilia, Dinosauria,
Ornithischia, Thyreophora, Stegosauria, Huayangosauridae.
Species: R. northamptoni
(type).
Diet: Herbivore.
Size: In the past estimated about 4 meters
long, but given the severe lack of fossils this is highly speculative.
Known locations: England, Sussex.
Time period: Early Cretaceous.
Fossil representation: Partial right mandible
(lower jaw).
The
holotype fossil of a partial jaw of Regnosaurus was
recovered by Gideon
Mantell who considered it to belong to an unknown large prehistoric
animal. Mantell would later name his animal Igaunodon,
though it
was still referred to as a big lizard since the word dinosaur had still
not been invented. Mantell realised that he had made a mistake when
the real jaws of Igaunodon began to be recovered
and so created the
genus Regnosaurus.
So
far the only definitive fossil of Regnosaurus is
the original jaw bone
and this is why the genus today is considered a nomen dubium.
Unless remains that include an identical jaw segment are ever found,
it is impossible to assign any further fossil discoveries to this
genus. This is why even though isolated remains which have been
considered to belong to the genus are not officially declared to be a
part of it; the validity of the remains simply can’t be proven.
Usually
Regnosaurus is interpreted as being part of a
stegosaur, perhaps even
being closely related to ones like Huayangosaurus,
making it a
huayanosaurid. Other palaeontologists have had different opinions
about the specimens in the past however, with John Ostrom thinking
that it might be a sauropod, to even Alfred Romer thinking that it
should be a synonym to Hylaeosaurus, one of the
three dinosaurs
(the others being Igaunodon and Megalosaurus)
that were used by
Richard Owen to define the Dinosauria in 1842.
Further reading
- Memoir on a portion of the lower jaw of the Iguanodon,
and on the
remains of the Hyl�osaurus and other Saurians,
discovered in the
Strata of Tilgate Forest, in Sussex, Gideon Mantell - 1841.
- On the structure of the jaws and teeth of the Iguanodon,
Gideon
Mantell - 1848.