''Gideonmantellia'' is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of basal

ornithopod Ornithopoda () is a clade of ornithischian dinosaurs, called ornithopods (). They represent one of the most successful groups of herbivorous dinosaurs during the Cretaceous. The most primitive members of the group were bipedal and relatively sm ...

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutio ...

known from the

Early Cretaceous The Early Cretaceous (geochronology, geochronological name) or the Lower Cretaceous (chronostratigraphy, chronostratigraphic name) is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 143.1 ...

(

Barremian The Barremian is an age in the geologic timescale (or a chronostratigraphic stage) between 125.77 Ma (million years ago) and 121.4 ± 1.0 Ma (Historically, this stage was placed at 129.4 million to approximately 125 million years ago) It is a ...

stage)

Camarillas Formation The Camarillas Formation is a geological formation in the Teruel Province of Aragón, Spain whose strata date back to the Early Cretaceous (Barremian stage). The sandstones, mudstones and conglomerates of the formation, that due to syn-sedimen ...

of Galve,

Province of Teruel Teruel ( Catalan: ''Terol'' ) is a province of Aragon, in the northeast of Spain. The capital is Teruel. It is bordered by the provinces of Tarragona, Castellón, Valencia (including its exclave Rincón de Ademuz), Cuenca, Guadalajara, and Z ...

Spain Spain, or the Kingdom of Spain, is a country in Southern Europe, Southern and Western Europe with territories in North Africa. Featuring the Punta de Tarifa, southernmost point of continental Europe, it is the largest country in Southern Eur ...

. It contains a single species, ''Gideonmantellia amosanjuanae''.

Discovery and naming

In 1982, amateur palaeontologist José María Herrero Marzo together with his son Jesús uncovered in a loam pit near Galve, the ''Poyales Barranco Canales'' site, the remains of a small euornithopod. In 1987 from this material by

José Luis Sanz José Luis Sanz Ruiz (born 21 September 1968) is a Spanish politician. He served as a senator from 2011 to 2023 with a brief interlude in 2019, and as a member of the Parliament of Andalusia from 2000 to 2012. He was mayor of Tomares from 2007 to ...

a left

femur The femur (; : femurs or femora ), or thigh bone is the only long bone, bone in the thigh — the region of the lower limb between the hip and the knee. In many quadrupeds, four-legged animals the femur is the upper bone of the hindleg. The Femo ...

and ilium were described, which he referred to ''

Hypsilophodon ''Hypsilophodon'' (; meaning "high-crested tooth") is a neornithischian dinosaur genus from the Early Cretaceous period of England. It has traditionally been considered an early member of the group Ornithopoda, but recent research has put this ...

foxii''. In 1995 José Ignacio Ruiz-Omeñaca realised the find represented a separate

taxon In biology, a taxon (back-formation from ''taxonomy''; : taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and ...

, after he had further prepared the bones in 1994 and 1995. Ruiz-Omeñaca continued his studies from 1996, as part of his thesis. In 2001 he published a more detailed and complete description, in 2004 reaffirming that a new species had been discovered. In 2006, in his doctoral thesis he named this ''Gideonmantellia amosanjuanae''; as a '' nomen ex dissertatione'' this name was as yet invalid though.Ruiz-Omeñaca, J.I., 2006, ''Restos directos de dinosaurios (Saurischia, Ornithischia) en el Barremiense (Cretácico Inferior) de la Cordillera Ibérica en Aragón (Teruel, España)''. Tesis Doctoral, Facultad de Ciencias, Universidad de Zaragoza, España pp 584 In 2012, the

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

''Gideonmantellia amosanjuanae'' was validly named and redescribed by Ruiz-Omeñaca, José Ignacio Canudo, Gloria Cuenca-Bescós, Penélope Cruzado-Caballero, José Manuel Gasca and Miguel Moreno-Azanza. The generic name honours the first describer of ''Hypsilophodon'',

Gideon Mantell Gideon Algernon Mantell Membership of the Royal College of Surgeons, MRCS Fellow of the Royal Society, FRS (3 February 1790 – 10 November 1852) was an English obstetrician, geologist and paleontology, palaeontologist. His attempts to reconstr ...

. The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

honours the late palaeontologist

Olga María Amo Sanjuán Olga may refer to: People and fictional characters * Olga (name), a given name, including a list of people and fictional characters named Olga or Olha * Michael Algar (born 1962), English singer also known as "Olga" Places Russia * Olga, Russia ...

, who studied the Cretaceous Galve fauna. The

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

, MPG-PBCH, was found in a

fluvial A river is a natural stream of fresh water that flows on land or inside caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of its course if it ru ...

deposit of the

, dating from the early Barremian. It consists of a partial articulated skeleton, lacking the skull, of a juvenile individual, including thirty-three vertebrae of the back, hip and tail, twenty-one fragments of the

neural arch Each vertebra (: vertebrae) is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spinal ...

es, six chevrons, rib fragments, ossified tendons, the left pelvis and both hindlimbs. The specimen is part of the collection of the

Museo Paleontológico de Galve Museo may refer to: * ''Museum'' (2018 film), Mexican drama heist film * Museo station, station on line 1 of the Naples Metro {{disambiguation ...

and displayed in the palaeontological hall of the townhall of Galve.

Phylogeny

The taxon was in 1995 and 2001 assigned to the

Hypsilophodontidae Hypsilophodontidae (or Hypsilophodontia) is a traditionally used family (biology), family of ornithopod dinosaurs, generally considered invalid today. It historically included many small bodied bipedal neornithischian taxa from around the world, ...

. Today this is considered an unnatural

paraphyletic Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

group and ''Gideonmantellia'' was in 2012 placed in a relatively basal position in the group

Ornithopoda Ornithopoda () is a clade of ornithischian dinosaurs, called ornithopods (). They represent one of the most successful groups of herbivorous dinosaurs during the Cretaceous. The most primitive members of the group were bipedal and relatively sm ...

. More recently, a 2017 study by Madzia ''et al.'' describing the genus ''

Burianosaurus ''Burianosaurus'' is an extinct genus of ornithopod dinosaur that lived in what is now the Czech Republic (it was found in 2003 near the city of Kutná Hora), being the first validly named dinosaur from that country. The type species, ''B. august ...

'' found ''Gideonmantellia'' to be the most basal ornithopod. The

cladogram A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ...

is reproduced below:

References

{{Taxonbar, from=Q2457727 Ornithopoda Dinosaur genera Barremian dinosaurs Camarillas Formation Fossil taxa described in 2012 Dinosaurs of Spain