''Aralazhdarcho'' is a

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 ...

azhdarchid Azhdarchidae (from the Persian word , , a dragon-like creature in Persian mythology) is a family of pterosaurs known primarily from the Late Cretaceous Period, though an isolated vertebra apparently from an azhdarchid is known from the Early Cre ...

pterosaur Pterosaurs are an extinct clade of flying reptiles in the order Pterosauria. They existed during most of the Mesozoic: from the Late Triassic to the end of the Cretaceous (228 million to 66 million years ago). Pterosaurs are the earli ...

that lived during the

Santonian The Santonian is an age in the geologic timescale or a chronostratigraphic stage. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series. It spans the time between 86.3 ± 0.7 mya ( million years ago) and 83.6 ± 0.7 m ...

to the early Campanian ages of the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...

period in what is now

Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a landlocked country primarily in Central Asia, with a European Kazakhstan, small portion in Eastern Europe. It borders Russia to the Kazakhstan–Russia border, north and west, China to th ...

. The type and only known species is ''Aralazhdarcho bostobensis'', named and described by Russian paleontologist Alexander Averianov. Its remains were found in the Bostobe Formation of Kazakhstan. The generic name combines the

Aral Sea The Aral Sea () was an endorheic lake lying between Kazakhstan to its north and Uzbekistan to its south, which began shrinking in the 1960s and had largely dried up into desert by the 2010s. It was in the Aktobe and Kyzylorda regions of Kazakhst ...

and the related genus ''

Azhdarcho ''Azhdarcho'' is a genus of azhdarchid pterosaur from the late Cretaceous Period (geology), Period of the Bissekty Formation (middle Turonian stage, about 92 million years ago) of Uzbekistan, as well as the Zhirkindek Formation of Kazakhstan a ...

'', while 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 ...

refers to its origin from the Bostobe Formation. Due to its toothless anatomy and the geological age of its fossil remains, ''Aralazhdarcho'' was assigned to the family

Azhdarchidae Azhdarchidae (from the Persian word , , a dragon-like creature in Persian mythology) is a family of pterosaurs known primarily from the Late Cretaceous Period, though an isolated vertebra apparently from an azhdarchid is known from the Early Cre ...

Phylogenetic analyses In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as Computational phylogenetics, phylogenetic inference. It infers the relationship among organ ...

would often recover it in a

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

alongside ''

Phosphatodraco ''Phosphatodraco'' is a genus of azhdarchid pterosaur that lived during the Late Cretaceous of what is now Morocco. In 2000, a pterosaur specimen consisting of five Cervical vertebrae, cervical (neck) vertebrae was discovered in the Ouled Abdou ...

'' from Morocco. The pterosaur genus '' Samrukia'' has been speculated to be a

junior synonym In taxonomy, the scientific classification of living organisms, a synonym is an alternative scientific name for the accepted scientific name of a taxon. The botanical and zoological codes of nomenclature treat the concept of synonymy differently. ...

of ''Aralazhdarcho''.

Etymology

''Aralazhdarcho bostobensis'' as a

and

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 ...

was named in 2007 by Russian paleontologist Alexander Averianov. However, 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 ...

specimen had already been described back in 2004. The generic name ''Aralazhdarcho'' is derived from the

and the related genus ''

'', while the

''bostobensis'' refers to its provenance from the Bostobe Formation.

Description

''Aralazhdarcho'' is based on holotype ZIN PH, no. 9/43, consisting of the anterior end of a neck

vertebra 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 spina ...

, probably the fifth or sixth. Several

paratype In zoology and botany, a paratype is a specimen of an organism that helps define what the scientific name of a species and other taxon actually represents, but it is not the holotype (and in botany is also neither an isotype (biology), isotype ...

s have also been referred: a jugal, a toothless lower jaw fragment, centra from vertebrae, the distal end of a scapula, the proximal end of a second phalanx of the left wing finger and the proximal end of a left femur, of which, however, the head has broken off. The remains were found at the Shakh-Shakh locality of Kazakhstan. The species '' Samrukia nessovi'', described separately from a partial lower jaw from the same formation, may have possibly been a

of ''Aralazhdarcho''.

Classification

In its description by Averianov, ''Aralazhdarcho'' was assigned to the family

, in view of its lack of teeth and geological age. Averianov presumed that it presented a more southern form of azhdarchid as opposed to the contemporary genus '' Bogolubovia'' (now assigned as a

pteranodontid The Pteranodontidae are a family of large pterosaurs from the Late Cretaceous of North America and possibly other continents including Europe and Africa. The family was named in 1876 by Othniel Charles Marsh. Pteranodontids had a distinctive, elon ...

instead of an azhdarchid), which was found more northern regions of Kazakhstan. The cladograms below show two different

phylogenetic analyses In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as Computational phylogenetics, phylogenetic inference. It infers the relationship among organ ...

that have recovered ''Aralazhdarcho'' within Azhdarchidae. The first one is by American paleontologist Brian Andres, in which he found ''Aralazhdarcho'' within the subfamily Quetzalcoatlinae, in a basal (primitive)

with ''

'' from Morocco. This close relationship between both azhdarchids would later be demonstrated again in a 2023 study by paleontologist Rodrigo Pêgas and colleagues, finding them in a trichotomy with '' Wellnhopterus'' from Texas. However, contrary to Andres in 2021, Pêgas and colleagues recovered ''Aralazhdarcho'' outside Quetzalcoatlinae in a more basal position within Azhdarchidae. Phosphatodraco

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 ...

by Andres (2021). Cladogram by Pêgas and colleagues (2023).

References

{{Portal bar, Paleontology Late Cretaceous pterosaurs of Asia Azhdarchidae Fossil taxa described in 2007

Etymology

Description

Classification

See also

References