''Jaklapallisaurus'' 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 ...

of unaysaurid

sauropodomorph Sauropodomorpha ( ; from Greek, meaning "lizard-footed forms") is an extinct clade of long-necked, herbivorous, saurischian dinosaurs that includes the sauropods and their ancestral relatives. Sauropods generally grew to very large sizes, had lo ...

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 ...

. It lived during the

Late Triassic The Late Triassic is the third and final epoch (geology), epoch of the Triassic geologic time scale, Period in the geologic time scale, spanning the time between annum, Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch a ...

period (late

Norian The Norian is a division of the Triassic geological period, Period. It has the rank of an age (geology), age (geochronology) or stage (stratigraphy), stage (chronostratigraphy). It lasted from ~227.3 to Mya (unit), million years ago. It was prec ...

to earliest

Rhaetian The Rhaetian is the latest age (geology), age of the Triassic period (geology), Period (in geochronology) or the uppermost stage (stratigraphy), stage of the Triassic system (stratigraphy), System (in chronostratigraphy). It was preceded by the N ...

) in what is now

Telangana Telangana is a States and union territories of India, state in India situated in the Southern India, south-central part of the Indian subcontinent on the high Deccan Plateau. It is the List of states and union territories of India by area, ele ...

, central

India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...

.The genus is

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unisp ...

, only including the species ''Jaklapallisaurus asymmetricus''.

Discovery and naming

The ''Jaklapallisaurus''

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, ISI R274, consists of

postcrania The postcranium ("behind the cranium"; plural: postcrania) or postcranial skeleton in zoology and vertebrate paleontology is the skeleton apart from the skull. The postcranium encompasses the axial skeleton, which includes the entirety of the verte ...

l material which was collected from the Upper Maleri Formation (late Norian–earliest Rhaetian) of the Pranhita–Godavari Basin. The specimen includes a probable anterior dorsal vertebra, an anterior caudal vertebra, and right distal end of femur, tibia, astragalus, metatarsals I IV, and pedal phalanges I-1 and II-1. It was first named by Fernando E. Novas, Martin D. Ezcurra, Sankar Chatterjee and Tharavat S. Kutty in

2011 The year marked the start of a Arab Spring, series of protests and revolutions throughout the Arab world advocating for democracy, reform, and economic recovery, later leading to the depositions of world leaders in Tunisia, Egypt, and Yemen ...

. 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 ...

is ''Jaklapallisaurus asymmetrica''. ISI R279, a partially complete right

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 ...

which was collected from the Lower Dharmaram Formation (latest Norian–Rhaetian) was originally referred to ''Jaklapallisaurus''. However, later research proved that the referral is based on weak grounds, and the presence of the species in that stratigraphic unit should be based on a more taxonomically informative specimen. The generic name is derived from the Indian town of ''Jaklapalli'' which is close to the type locality. 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 the highly asymmetrical astragalus of this species in distal view. In 2023, the ending of the Latinized specific epithet was changed from the female "asymmetrica" to the masculine "asymmetricus" because the ending of the Latinized genus ''Jakalapallisaurus'' is masculine. This modification is based on the Article 34 of the

International Code of Zoological Nomenclature The International Code of Zoological Nomenclature (ICZN) is a widely accepted Convention (norm), convention in zoology that rules the formal scientific name, scientific naming of organisms treated as animals. It is also informally known as the I ...

. The ''Jaklapallisaurus'' fossil material was found along with the guaibasaurid sauropodomorph '' Nambalia'' and two basal dinosauriforms.

Classification

In their 2023 description of the osteology of ''Jaklapallisaurus'', Ezcurra et al. performed a

phylogenetic analysis In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical data ...

of bagualosaurians, recovering it as 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 ...

to ''

Macrocollum ''Macrocollum'' is a genus of unaysauridae, unaysaurid sauropodomorph dinosaur that lived during the Late Triassic period (geology), period (early Norian) in what is now Brazil. It is one of the oldest dinosaurs known. Discovery and naming ''Mac ...

'', in a clade also containing ''

Unaysaurus ''Unaysaurus'' is a genus of unaysauridae, unaysaurid sauropodomorpha, sauropodomorph herbivore dinosaur. Discovered in southern Brazil, in the geopark of Paleorrota, in 1998, and announced in a press conference on Thursday, December 3, 2004, it ...

'', called Unaysauridae. The results of their analysis are shown in the cladogram below:

References

{{Taxonbar, from=Q1705592 Unaysauridae Dinosaur genera Rhaetian dinosaurs Fossil taxa described in 2011 Taxa named by Fernando Novas Taxa named by Sankar Chatterjee Dinosaurs of India