''Archaeovaranus'' (meaning "ancient '' Varanus''") is genus of

varanid The Varanidae are a family of lizards in the superfamily Varanoidea and order Anguimorpha. The family, a group of carnivorous and frugivorous lizards, includes the living genus '' Varanus'' and a number of extinct genera more closely related ...

lizard from the early

Eocene The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...

(

Ypresian In the geologic timescale the Ypresian is the oldest age (geology), age or lowest stage (stratigraphy), stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by th ...

) Yuhuangding Formation of

Hubei Province Hubei is a province in Central China. It has the seventh-largest economy among Chinese provinces, the second-largest within Central China, and the third-largest among inland provinces. Its provincial capital at Wuhan serves as a major politi ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

. The genus contains a single species, ''Archaeovaranus lii'', known from a nearly complete skeleton. 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 ...

, which includes an intact skull, is associated but disarticulated. ''Archaeovaranus'' fills a gap in the varanid fossil record, as it represents a

stem Stem or STEM most commonly refers to: * Plant stem, a structural axis of a vascular plant * Stem group * Science, technology, engineering, and mathematics Stem or STEM can also refer to: Language and writing * Word stem, part of a word respon ...

-varanid from the early Eocene of East Asia, and is the closest known relative of '' Varanus''.

Discovery and naming

The holotype specimen of ''Archaeovaranus'', IVPP V 22770, was discovered at the Dajian locality of the Yuhuangding Formation near Danjiangkou, Hubei Province, China. The generic name, "''Archaeovaranus''," combines the

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

"archaīos," meaning "ancient," with a reference to the closely related ''Varanus''. "''Varanus''" is derived from the

Arabic Arabic (, , or , ) is a Central Semitic languages, Central Semitic language of the Afroasiatic languages, Afroasiatic language family spoken primarily in the Arab world. The International Organization for Standardization (ISO) assigns lang ...

"waral," meaning "lizard beast." The specific name, "''lii''," honors the paleontologist Chuankui Li, whose research included studies of the ''Archaeovaranus'' type locality.

Description

The holotype specimen represents an adult individual, around 16 years old at the time of death. However, a lack of fusion at the

distal Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position provi ...

ends of the

humerus The humerus (; : humeri) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius (bone), radius and ulna, and consists of three sections. The humeral upper extrem ...

and

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 ...

suggest that the individual was still growing. The body size is approximately equivalent to ''Varanus'' ''salvator''''.''

Taxonomy

''Archaeovaranus'' was found in the study to be the closest known relative of modern monitor lizards belonging to the genus '' Varanus.'' Cladogram after Dong et al. 2022.

Paleoecology

The mammals '' Rhombomylus'', '' Advenimus'', '' Asiocoryphodon'' and '' Danjiangia'' are also known from layers of the Yuhuangding Formation.

References

{{Taxonbar, from=Q111170126 Fossil taxa described in 2022 Eocene lizards Fossils of China Eocene Asia Monitor lizards Eocene reptiles of Asia Prehistoric lizard genera