Lusitanosaurus is a genus

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 basal thyreophora

Thyreophora

The Thyreophora were a subgroup of the ornithischian dinosaurs...

n dinosaur

Dinosaur

Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...

 from the Early Jurassic

Early Jurassic

The Early Jurassic epoch is the earliest of three epochs of the Jurassic period...

 of Portugal

Portugal

Portugal , officially the Portuguese Republic is a country situated in southwestern Europe on the Iberian Peninsula. Portugal is the westernmost country of Europe, and is bordered by the Atlantic Ocean to the West and South and by Spain to the North and East. The Atlantic archipelagos of the...

.

The genus was first described by Albert-Félix de Lapparent

Albert-Félix de Lapparent

Albert-Félix de Lapparent was a French palaeontologist. He was also a Sulpician priest. He undertook a number of fossil-hunting explorations in the Sahara desert. He contributed greatly to our knowledge of dinosaurs and other prehistoric creatures...

 and Georges Zbyszewski in 1957. 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 Lusitanosaurus liasicus. The generic name is derived from Lusitania

Lusitania

Lusitania or Hispania Lusitania was an ancient Roman province including approximately all of modern Portugal south of the Douro river and part of modern Spain . It was named after the Lusitani or Lusitanian people...

, the ancient 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...

 name for the region. The specific name refers to the Lias

Lias

Lias may refer to:*In geology:**The Lias Group, a group in the stratigraphy of Great Britain, formed during the Late Triassic to Early Jurassic epochs. It includes the Blue Lias and White Lias...

.

The holotype

Holotype

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...

 is part of the collection of the Museu de História Natural da Universidade de Lisboa. The exact location of the find and the date of collection are unknown, which makes a correct geological dating difficult, but it can be inferred from the matrix rock that it has been discovered near São Pedro de Moel

São Pedro de Moel

São Pedro de Moel is a beach community near to the city of Marinha Grande in the district of Leiria, Portugal.It is located within the Pinhal de Leiria, south of the mouth of Ribeira de Moel. It is a seaside village, west of the cities of Marinha Grande and Leiria.In 1463 Don Afonso V gave São...

, in strata from the Sinemurian

Sinemurian

In the geologic timescale, the Sinemurian is an age or stage in the Early or Lower Jurassic epoch or series. It spans the time between 196.5 ± 2 Ma and 189.6 ± 1.5 Ma...

 (Early Jurassic

Early Jurassic

The Early Jurassic epoch is the earliest of three epochs of the Jurassic period...

). This would make it the oldest known dinosaur from Portugal. The fossil consists of a single partial left maxilla

Maxilla

The maxilla is a fusion of two bones along the palatal fissure that form the upper jaw. This is similar to the mandible , which is also a fusion of two halves at the mental symphysis. Sometimes The maxilla (plural: maxillae) is a fusion of two bones along the palatal fissure that form the upper...

, an upper jaw bone, with seven teeth.

Originally assigned to the Stegosauria

Stegosauria

Known colloquially as stegosaurs, the Stegosauria are a group of herbivorous dinosaurs of the Jurassic and Early Cretaceous Periods, being found mostly in the Northern Hemisphere, predominantly in what is now North America and China....

 by de Lapparent, Lusitanosaurus is today considered a basal member of the Thyreophora

Thyreophora

The Thyreophora were a subgroup of the ornithischian dinosaurs...

, perhaps belonging to the Scelidosauridae. Some authors consider it a nomen dubium

Nomen dubium

In zoological nomenclature, a nomen dubium is a scientific name that is of unknown or doubtful application...

.