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''Guidraco'' (Chin. ''gui'' (鬼) "malicious ghost" + Lat. ''draco'' "dragon") is an extinct
genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...
of toothed
pterodactyloid Pterodactyloidea (derived from the Greek words ''πτερόν'' (''pterón'', for usual ''ptéryx'') "wing", and ''δάκτυλος'' (''dáktylos'') "finger" meaning "winged finger", "wing-finger" or "finger-wing") is one of the two traditional ...
pterosaur Pterosaurs (; from Greek ''pteron'' and ''sauros'', meaning "wing lizard") is an extinct clade of flying reptiles in the Order (biology), order, Pterosauria. They existed during most of the Mesozoic: from the Late Triassic to the end of the Cre ...
known 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 Pr ...
of
Liaoning Province Liaoning () is a coastal province in Northeast China that is the smallest, southernmost, and most populous province in the region. With its capital at Shenyang, it is located on the northern shore of the Yellow Sea, and is the northernmost ...
, northeast China. According to many recent studies, ''Guidraco'' is a member of the group
Anhanguerinae Anhangueridae is a group of pterosaurs within the suborder Pterodactyloidea. They were among the last pterosaurs to possess teeth. A recent study discussing the group considered the Anhangueridae to be typified by a premaxillary crest and a later ...
, a subfamily belonging to the larger group Anhangueridae.


Discovery

''Guidraco'' is known only from 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 seve ...
IVPP The Institute of Vertebrate Paleontology and Paleoanthropology (IVPP; ) of China is a research institution and collections repository for fossils, including many dinosaur and pterosaur specimens (many from the Yixian Formation). As its name sugges ...
 V17083, an articulated partial
skeleton A skeleton is the structural frame that supports the body of an animal. There are several types of skeletons, including the exoskeleton, which is the stable outer shell of an organism, the endoskeleton, which forms the support structure inside ...
consisting of a nearly complete
skull The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, t ...
, lower jaws and a series of four, second to fifth, cervical vertebrae. It was collected at Sihedang near
Lingyuan Lingyuan () is a city in the west of Liaoning province in Northeast China, bordering Hebei province and Inner Mongolia. It is under the administration of Chaoyang City, which lies to the east-northeast. Administrative Divisions There are eigh ...
City in the
Liaoning Province Liaoning () is a coastal province in Northeast China that is the smallest, southernmost, and most populous province in the region. With its capital at Shenyang, it is located on the northern shore of the Yellow Sea, and is the northernmost ...
from the
Jiufotang Formation The Jiufotang Formation ( Chinese: 九佛堂组, pinyin: ''jiǔfótáng zǔ'') is an Early Cretaceous geological formation in Chaoyang, Liaoning which has yielded fossils of feathered dinosaurs, primitive birds, pterosaurs, and other organisms (see ...
, dating to the
Aptian The Aptian is an age in the geologic timescale or a stage in the stratigraphic column. It is a subdivision of the Early or Lower Cretaceous Epoch or Series and encompasses the time from 121.4 ± 1.0 Ma to 113.0 ± 1.0 Ma (million years ag ...
stage of 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 Pr ...
, about 120 
million years ago The abbreviation Myr, "million years", is a unit of a quantity of (i.e. ) years, or 31.556926 teraseconds. Usage Myr (million years) is in common use in fields such as Earth science and cosmology. Myr is also used with Mya (million years ago). ...
.


Etymology

''Guidraco'' was first described and named by Wang Xiaolin, Alexander W.A. Kellner,
Jiang Shunxing Jiang may refer to: * ''Jiang'' (rank), rank held by general officers in the military of China *Jiang (surname), several Chinese surnames **Jiang Zemin (1926–2022), as general secretary of the Chinese Communist Party *Jiang River The Jiang Rive ...
and
Cheng Xin ''Death's End'' () is a science fiction novel by the Chinese writer Liu Cixin. It is the third novel in the trilogy titled Remembrance of Earth's Past, following the Hugo Award-winning novel '' The Three-Body Problem'' and its sequel, ''The Dar ...
in 2012 and 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( ...
is ''Guidraco venator''. The generic name is derived from Chinese ''gui'' (鬼), "malicious ghost", and from
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 ...
''draco'', "dragon". The specific name means "hunter" in Latin.


Description

The holotype
skull The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, t ...
of ''Guidraco'' has a length of . It is very elongated with a hollow profile but not very pointed as the upper edge and the line of the jaw run nearly parallel over most of their length. The ensuing relative robustness of the snout is reinforced by a short main skull opening, a ''fenestra nasoantorbitalis'' with just a quarter of skull length, and a lower jaw equalling the rostrum in depth. The snout lacks a crest. Above the eye sockets however, the line of the top of the snout curves steeply upwards, resulting in a very large crest on the frontals, as high as the posterior part of the skull is deep, ending in a rounded top. Due to the angling of the skull roof the crest slightly points forwards and its base extends to the back of the roof; however, the parietal is not part of it. In front of the crest large impressions of soft tissue are visible but these are plant remains. Further diagnostic features of the skull include an infratemporal fenestra with a narrow lower end, and a
jugal The jugal is a skull bone found in most reptiles, amphibians and birds. In mammals, the jugal is often called the malar or zygomatic. It is connected to the quadratojugal and maxilla, as well as other bones, which may vary by species. Anat ...
of which the front branch extends no further than the front edge of the ''fenestra nasoantorbitalis''. The teeth of ''Guidraco'' are very distinctive. Of the twenty-three teeth of the upper jaw the first is long and very narrow, pointing nearly horizontally forward. The next three teeth are enormous in size, very long, robust, pointed and slightly recurved. They gradually point more downwards. These are followed by a series of three medium-length downward-pointing straight teeth, of which the middle one, the sixth, is the shortest. The remaining thirteen teeth constitute a long row of small elements gradually diminishing in size. This arrangement is mirrored by the eighteen teeth of the lower jaw. Here however, a forward pointing tooth is lacking. The first four teeth are of great size, even longer than their counterparts of the upper jaw. Next is a series of three straight teeth of medium height, followed by a row of eleven increasingly smaller elements for a grand total in the head of eighty-two teeth. With the fossil, the beak is closed and due to their extreme length the front teeth extend far beyond the upper and lower edges of the head, the protruding parts being up to twice as long as the depth of the snout or lower jaw. The teeth can also be divided into two types according to their built: the first nine teeth of the upper jaw and eight teeth of the lower jaw have vertical ridges on the back of their enamel; the back teeth have a uniformly smooth enamel and thickened crown bases, giving them a more triangular outline. Though not having the form of a true rosette because the jaw ends were not expanded, the intermeshing front teeth functioned as a "prey grab" to catch slippery animals; the describers therefore consider ''Guidraco'' to have been a fish-eater. The neck vertebrae are moderately elongated, keeled and possess large pneumatic openings on their sides, the access by which the air sac of the neck could enter their hollow interiors. The
axis An axis (plural ''axes'') is an imaginary line around which an object rotates or is symmetrical. Axis may also refer to: Mathematics * Axis of rotation: see rotation around a fixed axis * Axis (mathematics), a designator for a Cartesian-coordinat ...
bears a spiked spine.


Phylogeny

''Guidraco'' was by the describers assigned to the Pteranodontoidea ''sensu'' Kellner. A
phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...
analysis found it to be the
sister taxon In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...
of the
Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...
ian '' Ludodactylus'', the two species together forming a clade that was closely related to the
Istiodactylidae Istiodactylidae is a small family of pterosaurs. This family was named in 2001 after the type genus ''Istiodactylus'' was discovered not to be a member of the genus '' Ornithodesmus''. Systematics and distribution Remains of taxa that can be c ...
and the Anhangueridae. The fact that a Chinese form is closely related to a South American species would indicate a large faunal interchange between continents in this period. This result was later replicated by Wang ''et al.'' in 2014 and Wu ''et al.'' in 2017. Also in 2014 however, Brian Andres and colleagues recovered an alternate position for ''Guidraco'' among the family Boreopteridae. Their cladogram is shown on the left Later, in 2019, many subsequent analyses reassigned ''Guidraco'' to the family Anhangueridae, specifically to the subfamily
Anhanguerinae Anhangueridae is a group of pterosaurs within the suborder Pterodactyloidea. They were among the last pterosaurs to possess teeth. A recent study discussing the group considered the Anhangueridae to be typified by a premaxillary crest and a later ...
, sister taxon to the genera ''
Caulkicephalus ''Caulkicephalus'' is a genus of anhanguerid pterosaur from the Isle of Wight off the coast of England. It lived during the Early Cretaceous period, about 130 million years ago. Discovery and naming Between 1995 and 2003, bone fragments of an ...
'' and ''Ludodactylus''.Borja Holgado, Rodrigo V. Pêgas, José Ignacio Canudo, Josep Fortuny, Taissa Rodrigues, Julio Company & Alexander W.A. Kellner, 2019, "On a new crested pterodactyloid from the Early Cretaceous of the Iberian Peninsula and the radiation of the clade Anhangueria", ''Scientific Reports'' 9: 4940 Pêgas, R.V., Holgado, B., Leal, M.E.C., 2019. "''Targaryendraco wiedenrothi'' gen. nov. (Pterodactyloidea, Pteranodontoidea, Lanceodontia) and recognition of a new cosmopolitan lineage of Cretaceous toothed pterodactyloids", ''Historical Biology'', 1–15. doi:10.1080/08912963.2019.1690482 This would confirm that ''Guidraco'' is indeed closely related to ''Ludodactylus''. The cladogram on the right is a topology made by Borja Holgado and Rodrigo Pêgas in 2020. Topology 1: Andres ''et al.'' (2014). Topology 2: Holgado & Pêgas (2020).


See also

* List of pterosaur genera *
Timeline of pterosaur research This timeline of pterosaur research is a chronologically ordered list of important fossil discoveries, controversies of interpretation, and Biological taxonomy, taxonomic revisions of pterosaurs, the famed flying reptiles of the Mesozoic Era (ge ...


References

{{Portal bar, Paleontology, Cretaceous, China Early Cretaceous pterosaurs of Asia Fossil taxa described in 2012 Pteranodontoids Taxa named by Alexander Kellner