''Camarillasaurus'' (meaning " Camarillas lizard") is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

spinosaurid The Spinosauridae (or spinosaurids) are a clade or family of tetanuran theropod dinosaurs comprising ten to seventeen known genera. They came into prominence during the Cretaceous period. Spinosaurid fossils have been recovered worldwide, includi ...

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

from the

Early Cretaceous The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Pro ...

period Period may refer to: Common uses * Era, a length or span of time * Full stop (or period), a punctuation mark Arts, entertainment, and media * Period (music), a concept in musical composition * Periodic sentence (or rhetorical period), a concept ...

(

Barremian The Barremian is an age in the geologic timescale (or a chronostratigraphic stage) between 129.4 ± 1.5 Ma (million years ago) and 121.4 ± 1.0 Ma). It is a subdivision of the Early Cretaceous Epoch (or Lower Cretaceous Series). It is preceded ...

) of Camarillas,

Teruel Province 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 Zar ...

, in what is now northeastern Spain. Described in 2014, it was originally identified as a

ceratosaurian Ceratosaurs are members of the clade Ceratosauria, a group of dinosaurs defined as all theropods sharing a more recent common ancestor with ''Ceratosaurus'' than with birds. The oldest known ceratosaur, ''Saltriovenator'', dates to the earliest ...

theropod Theropoda (; ), whose members are known as theropods, is a dinosaur clade that is characterized by hollow bones and three toes and claws on each limb. Theropods are generally classed as a group of saurischian dinosaurs. They were ancestrally c ...

, before being referred to the Spinosauridae in 2021.

History of research

Fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

s of ''Camarillasaurus'' were discovered in the

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-sediment ...

. The

type species In 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 species that contains the biological type specimen ...

, ''Camarillasaurus cirugedae'', was described by

palaeontologists Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of fossi ...

Bárbara Sánchez-Hernández and

Michael J. Benton Michael James Benton One or more of the preceding sentences incorporates text from the royalsociety.org website where: (born 8 April 1956) is a British palaeontologist, and professor of vertebrate palaeontology in the School of Earth Sciences ...

. The describers considered it to be a basal

ceratosaur Ceratosaurs are members of the clade Ceratosauria, a group of dinosaurs defined as all theropods sharing a more recent common ancestor with ''Ceratosaurus'' than with birds. The oldest known ceratosaur, ''Saltriovenator'', dates to the earliest ...

, somewhat unusual given its young age. However, in an abstract given at the EAVP 2019 conference, Oliver Rauhut and colleagues suggested it is a member of the

Spinosauridae The Spinosauridae (or spinosaurids) are a clade or family of tetanuran theropod dinosaurs comprising ten to seventeen known genera. They came into prominence during the Cretaceous period. Spinosaurid fossils have been recovered worldwide, includin ...

rather than a ceratosaur, based on characters of the posterior

caudal vertebrae The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic ...

and newly excavated material at the type locality; a chapter of a 2019 dissertation by Adun Samathi concurred with that conclusion. In 2021, the chapter was formally published as a paper, with the same conclusion; Samathi noted similarities with spinosaur material from Thailand and other taxa within the family. ''Camarillasaurus'' is one of four spinosaurid

taxa In biology, a taxon (back-formation from ''taxonomy''; plural 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 nam ...

known from the Iberian peninsula, the others being ''

Baryonyx ''Baryonyx'' () is a genus of theropod dinosaur which lived in the Barremian stage of the Early Cretaceous period, about 130–125 million years ago. The first skeleton was discovered in 1983 in the Smokejack Clay Pit, of Surrey, England, in se ...

,'' ''

Vallibonavenatrix ''Vallibonavenatrix'' (meaning "Vallibona huntress" after the town near where its remains were found) is a genus of spinosaurid dinosaur from the Early Cretaceous (Barremian) Arcillas de Morella Formation of Castellón, Spain. The type and onl ...

'', and ''

Iberospinus ''Iberospinus'' or (meaning " Iberian spine") is an extinct genus of spinosaurid dinosaur from the Early Cretaceous (Barremian) Papo Seco Formation of Portugal. The genus contains a single species, ''I. natarioi'', known from several assorted bo ...

''.

References

Early Cretaceous dinosaurs of Europe Barremian life Cretaceous Spain Fossils of Spain Fossil taxa described in 2014 Spinosaurids Taxa named by Michael Benton {{theropod-stub