''Vectiraptor'' (meaning "

Isle of Wight The Isle of Wight ( ) is a county in the English Channel, off the coast of Hampshire, from which it is separated by the Solent. It is the largest and second-most populous island of England. Referred to as 'The Island' by residents, the Isle of ...

thief") 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 ...

dromaeosaurid Dromaeosauridae () is a family of feathered theropod dinosaurs. They were generally small to medium-sized feathered carnivores that flourished in the Cretaceous Period. The name Dromaeosauridae means 'running lizards', from Greek ('), meaning ...

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

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 ...

aged

Wessex Formation The Wessex Formation is a fossil-rich English geological formation that dates from the Berriasian to Barremian stages (about 145–125 million years ago) of the Early Cretaceous. It forms part of the Wealden Group and underlies the younger Vecti ...

of the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and North ...

. The type and only species is ''Vectiraptor greeni'', known from associated

dorsal vertebrae In vertebrates, thoracic vertebrae compose the middle segment of the vertebral column, between the cervical vertebrae and the lumbar vertebrae. In humans, there are twelve thoracic vertebrae and they are intermediate in size between the cervical ...

and a partial

sacrum The sacrum (plural: ''sacra'' or ''sacrums''), in human anatomy, is a large, triangular bone at the base of the spine that forms by the fusing of the sacral vertebrae (S1S5) between ages 18 and 30. The sacrum situates at the upper, back part ...

Discovery and naming

''Vectiraptor'' was initially discovered by amateur paleontologist Mick Green in 2004 in rocks of the

, below the cliffs of Compton Bay on the

, United Kingdom. The finds form the

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

IWCMS. 2021.31.1-3, consisting of two

dorsal vertebra In vertebrates, thoracic vertebrae compose the middle segment of the vertebral column, between the cervical vertebrae and the lumbar vertebrae. In humans, there are twelve thoracic vertebrae and they are intermediate in size between the cervical ...

e. Later a partial

of three vertebrae, IWCMS. 2021.31.2, would be discovered by the late Nick Chase. The element has been determined to belong to the holotype as all fossil elements were discovered over a short time period, and each find was located within several metres of the others. The holotype represents an adult individual, the age of which was estimated at twenty to thirty years on the basis of growth lines in the bone cortex. The vertebrae were donated to the collection of the Isle of Wight County Museum Service. 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 ...

''Vectiraptor greeni'', would be erected by Nicholas Longrich, David Michael Martill and Megan Jacobs in 2021. The generic name, ''Vectiraptor'', combines the

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

words ''Vectis'', meaning "the Isle of Wight," and ''raptor'' meaning "thief". The specific name, ''greeni'', is in honour of Mick Green who initially discovered and prepared the

type material In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralizes the ...

. Of large and wide dromaeosaurid teeth previously reported from Wight, such as the specimens IWCMS.2002.1, IWCMS.2002.3, IWCMS.2002.4 and BMNH R 16510,Sweetman, S.C., 2004. "The first record of velociraptorine dinosaurs (Saurischia, Theropoda) from the Wealden (Early Cretaceous, Barremian) of southern England". ''Cretaceous Research'' 25: 353-364 the describing authors considered it likely that they in fact belonged to ''Vectiraptor'', though they were not formally referred.

Description

The body length of ''Vectiraptor'' was estimated to be . The holotype includes two partial dorsal vertebrae and parts of the sacrum. Although fragmentary, the material shows a combination of features found only in the

Dromaeosauridae Dromaeosauridae () is a family of feathered theropod dinosaurs. They were generally small to medium-sized feathered carnivores that flourished in the Cretaceous Period. The name Dromaeosauridae means 'running lizards', from Greek ('), meaning ...

, including relatively short and massive

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 i ...

, tall

neural spines 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 facets for the

ribs The rib cage, as an enclosure that comprises the ribs, vertebral column and sternum in the thorax of most vertebrates, protects vital organs such as the heart, lungs and great vessels. The sternum, together known as the thoracic cage, is a semi- ...

set on long stalks. Two

autapomorphies In phylogenetics, an autapomorphy is a distinctive feature, known as a derived trait, that is unique to a given taxon. That is, it is found only in one taxon, but not found in any others or outgroup taxa, not even those most closely related to t ...

, or unique derived traits, were established. With the front vertebrae of the back, the usual deep triangular depression at the underside of the side process is subdivided by an extra ridge. The

neural spine 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 i ...

s are robust with wide rough depressions for the attachment of ligaments. The vertebrae showed extensive pneumatisation. The dorsals had pleurocoels through which the air sacs of the respiratory system entered the vertebral bodies, forming large camellate air spaces. The diapophysal fossa also invaded the neural arch. The neural canals were expanded to behind, embaying the top of the centrum. The sacral vertebrae lacked pleurocoels and had a spongy bone structure. Their combined neural canal was so wide however, that it might have contained an air chamber, accessed by spaces between their partially fused neural arches.

Phylogeny

A number of features, including the animal's large size, short dorsals, the presence of openings in the posterior dorsal vertebrae for

air sacs Air sacs are spaces within an organism where there is the constant presence of air. Among modern animals, birds possess the most air sacs (9–11), with their extinct dinosaurian relatives showing a great increase in the pneumatization (presence ...

, and the tall and narrow in side view neural spines with ligament scars, suggest the animal is a member of, or related to, the

Eudromaeosauria Eudromaeosauria ("true dromaeosaurs") is a subgroup of terrestrial dromaeosaurid theropod dinosaurs. They were relatively small to medium-sized, feathered hypercarnivores (with diets consisting almost entirely of other terrestrial vertebrates) ...

. The resemblance to eudromaeosaurs from North America suggests a faunal exchange between North America and Europe.

References

Eudromaeosaurs Fossil taxa described in 2021 {{Improve categories, date=July 2022