Scientific Classification
Kingdom: Animalia
Phylum: Chordata
Class: Sauropsida
Superorder: Dinosauria
Order: -Not Described-
Suborder: -Not Described-
Family: -Not Described-
Genus: Newtonsaurus

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The Newtonsaurus was a dinosaur which is believed to have lived in the late Triassic period.
It is not yet described by any scientist and hence its existence is considered dubious. Its remains were discovered in the year 1899 and were classified under a different existing genus. Later, they were ascribed their own generic name ‘Newtonsaurus’. But because its bones did not prove to be diagnostically relevant, scientists have not been able to define or classify it. In fact, the name 'Newtonsaurus' is unofficial.
A name is considered official when a scientist publishes a research paper describing a set of remains and registers the name with the International Code of Zoological Nomenclature (ICZN). Unless this protocol is followed, the name remains available for anybody to use. Unless this dinosaur is described in detail, the name Newtonsaurus can be used for any other newly discovered animal.
The genus Newtonsaurus is deemed nomen nudum.

Nomen nudumg enera

• ‘Nomen’ is the Latin term or ‘name’ and ‘nudum’ is Latin for ‘nude’.
• When a zoological genus is considered nomen nudum,it indicates that the name of the genus is not recognized in its current state. The reason for it to unacceptable can be multifold.
• In the case of the Newtonsaurus, there isn’t enough information to qualify it as a valid genus. Thus, its name cannot be included in the ICZN.

Discovery of fossils
The fossils which are currently named Newtonsaurus were discovered in Wales in the United Kingdom in 1899. They were excavated in a natural geological structure which consisted of layers of sedimentary rocks. This particular area contains fossils from the Rhaetian age of the Triassic period.
The remains were discovered by paleontologist Edwin Tully Newton.

Age of fossils
The region of Wales in which the bones the bones of the Newtonsaurus were discovered yields fossils predominantly from the late Triassic period. Dinosaurs were present only in small numbers in the Triassic period. It was only after the Triassic- Jurassic extinction event that the dinosaurs had emerged as the dominant land species. Thus, the Newtonsaurus could possibly have been a dinosaur which survived this event.

Nature of fossils

• The remains of the Newtonsaurus resemble those of Ceratosaur dinosaurs. During the excavation in Wales, only a lower jaw was discovered. This jaw possessed sharp teeth which were curved backwards.
• Such teeth were seen carnivorous dinosaurs. Furthermore, the morphology of this jaw and the contours of its teeth marched ceratosaur dinosaurs. Also, the fossils of the Hence, the Newtonsaurus is presumed to be a ceratosaur.
• However, the jaw was not well preserved and determining the taxonomic location of a set remains based only on dentition is not plausible most of the times. Unless all teeth are present in the fossils and they are in an extremely good condition, such deductions cannot be made.

Etymology
The Newtonsaurus was named after its discovered Edwin Tully Newton. The term ‘-saurus’ is inspired from the Greek word ‘sauros’ which means ‘lizard’ in English. Hence, the name Newtonsaurus means ‘Newton’s lizard’.
The species name Newtonsaurus cambrensis was derived from the pen name of the famous Welsh chronicler and traveler Gerard de Barri. Barri wrote under the name Giraldius Cambrensis. This specific name was coined by E. T. Newton.
The new generic Newtonsaurus was selected by scientists Samuel Welles and David Pickering.

Classification

• The remains of the Newtonsaurus were originally ascribed to the genus Zanclodon in 1899. The Zanclodon was a Triassic archosaur. The location of the Zanclodon in the taxonomic chart is still debatable even today despite of it being a clearly described genus.
• A few years later, it was noticed that these teeth fragments were incongruous with the rest of the Zanclodon fossils. They were then shifted to the genus Megalosaurus, which is a theropod dinosaur.
• Finally in the year 1999, it was seen that the jaw and teeth fossils did not resemble those of the Megalosaurus either. Hence they were ascribed their own new genus.
• Samuel Welles did not venture to describe the exact classification of the Newtonsaurus. He stated that he believed it to be a ceratosaur, but was unable to provide adequate proof for it.

Ceratosaur dinosaurs

• Ceratosaurs were a subgroup among theropod dinosaurs. They were dinosaurs which were related to the Ceratosaurus. This clade was defined by Othneil Charles Marsh.
• Ceratosaurs were larger dinosaurs which walked on two feet. Their feeding habits were carnivorous. One of the most characteristic features of ceratosaurs was their reduced forelegs. Some of them could grasp things with their forelegs, but they were highly inflexible.
• These dinosaurs appeared on the earth during the Jurassic period and were present till the end of the Cretaceous period. The fossils of the Newtonsaurus date to the end of the Triassic period where the Jurassic period just began. Hence it is believed to be among the dinosaurs that gave rise to the killer Jurassic and Cretaceous theropods like the Tyrannosaurus.

Edwin Tully Newton
Edwin Tully Newton was an English geologist. He was born in Islington, Greater London in 1840.
The first article published by Newton was about bituminous coal. His interest in paleontology began about ten years after he graduated.
He retired in the year 1905. He led an active life even after his retirement. He served as the president of the Palaeontographical Society for seven years since 1921.
He passed away at the age of seventy.

Morphological features, habitat and related species
The Newtonsaurus is known only by its lower jaw. Skull fragments are poor determinants of physical characteristics, even when to taxonomy of the skull is known. In the case of the Newtonsaurus, its lineage is not known and hence scientists have been unable to judge its external appearance.
The fossils of the Newtonsaurus were discovered in Wales. In the late Triassic period, it consisted of woodlands and moors.
It is unknown which vertebrates the Newtonsaurus was related to. Some scientists believe that was related to the Ceratosaurus.

Conclusion
The fossils of the Newtonsaurus were discovered more than a century ago. But they do not resemble any known dinosaur correctly. Due to this, they were grouped under a new genus.
But this genus is undescribed. Unless more data is unearthed, the Newtonsaurus cannot be classified beyond clade Dinosauria.