''Tropicagama'' 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 large-bodied

lizard Lizard is the common name used for all Squamata, squamate reptiles other than snakes (and to a lesser extent amphisbaenians), encompassing over 7,000 species, ranging across all continents except Antarctica, as well as most Island#Oceanic isla ...

s in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Agamidae Agamidae is a family containing 582 species in 64 genera of iguanian lizards indigenous to Africa, Asia, Australia, and a few locations in Southern Europe. Many species are commonly called dragons or dragon lizards. Overview Phylogenetically ...

. 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 ...

, with only one species listed: ''Tropicagama temporalis'', commonly known as the swamplands lashtail or northern water dragon. This semi-arboreal species inhabits the tropical savannah woodlands of northern

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

, as well as parts of

New Guinea New Guinea (; Hiri Motu: ''Niu Gini''; , fossilized , also known as Papua or historically ) is the List of islands by area, world's second-largest island, with an area of . Located in Melanesia in the southwestern Pacific Ocean, the island is ...

and southeastern

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania, between the Indian Ocean, Indian and Pacific Ocean, Pacific oceans. Comprising over List of islands of Indonesia, 17,000 islands, including Sumatra, ...

Taxonomy

From its original description in 1867 until 2017, genus ''Tropicagama'' has previously been included in multiple other genera, including ''Amphibolurus'', ''Gemmatophora'', ''Gowidon'', ''Grammatophora'', ''Lophognathus'', and ''Physignathus''. The new genus – ''Tropicagama'' – was created by Melville ''et al.'' in 2018, after an extensive analysis of three genera (''

Amphibolurus ''Amphibolurus'' is a genus of lizards in the family Agamidae. The genus is endemic to Australia. Description Characteristics of the genus ''Amphibolurus'' include: * Moderate size nout–vent length * Long limbs and long tail * One to five cr ...

'', '' Gowidon'' and ''

Lophognathus ''Lophognathus'' is a genus of large-bodied agamid lizards, consisting of two species — ''L. gilberti'' and ''L. horneri'' — both of which are endemic to northern Australia. Along with several other closely related genera (e.g., ''Amphibolur ...

'') that have had long-standing inconsistencies in their taxonomic classification. The morphological and

mitochondrial DNA Mitochondrial DNA (mtDNA and mDNA) is the DNA located in the mitochondrion, mitochondria organelles in a eukaryotic cell that converts chemical energy from food into adenosine triphosphate (ATP). Mitochondrial DNA is a small portion of the D ...

analysis revealed that four distinct evolutionary lines were lumped in the former genus ''

''. As a result, the former genus ''Lophognathus'' has now been split into genera ''

'', '' Gowidon'', ''

'', and ''Tropicagama''. All of these genera are contained within subfamily

Amphibolurinae The Amphibolurinae are a subfamily of lizards in the family Agamidae. Members of this subfamily are found in Australia and New Guinea, although one species, the Chinese water dragon, is found in Southeast Asia. Genera Genera within the subfamily ...

Phylogeny and biogeography

Sequencing and analysis of mitochondrial DNA, along with

phylogenetic 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 dat ...

and divergence time analyses, reveals that the genus ''Tropicagama'' originated in the late

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

and early

Pliocene The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58Ma). It then migrated from New Guinea across Lydekker's Line into

Wallacea Wallacea is a biogeography, biogeographical designation for a group of mainly list of islands of Indonesia, Indonesian islands separated by deep-water straits from the Asian and Australia (continent), Australian continental shelf, continental ...

less than 1 Ma, during the mid-

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

epoch. Wallacea is a zone of mixing between

fauna Fauna (: faunae or faunas) is all of the animal life present in a particular region or time. The corresponding terms for plants and fungi are ''flora'' and '' funga'', respectively. Flora, fauna, funga and other forms of life are collectively ...

of the

Indomalayan The Indomalayan realm is one of the eight biogeographic realms. It extends across most of South and Southeast Asia and into the southern parts of East Asia. Also called the Oriental realm by biogeographers, Indomalaya spreads all over the Ind ...

and

Australasian Australasia is a subregion of Oceania, comprising Australia, New Zealand (overlapping with Polynesia), and sometimes including New Guinea and surrounding islands (overlapping with Melanesia). The term is used in a number of different contexts, ...

ecozones An ecozone may refer to: * Biogeographic realm, the broadest biogeographic division of Earth's land surface (referred to as ''ecozone'' by BBC) * Biome, a large collection of flora and fauna occupying a major habitat * Bioregion, an ecologically ...

. The eastern border of this zone is represented by a zoogeographical boundary known as Lydekker's Line, while the

Wallace Line The Wallace Line or Wallace's Line is a faunal boundary line drawn in 1859 by the British naturalist Alfred Russel Wallace and named by the English biologist Thomas Henry Huxley. It separates the biogeographic realms of Asia and 'Wallacea', a ...

defines the western border.

Distribution and habitat

''T. temporalis'' is mainly found in the far northern Australian coastal regions in the

Northern Territory The Northern Territory (abbreviated as NT; known formally as the Northern Territory of Australia and informally as the Territory) is an states and territories of Australia, Australian internal territory in the central and central-northern regi ...

and the western portion of the

Cape York Peninsula The Cape York Peninsula is a peninsula located in Far North Queensland, Australia. It is the largest wilderness in northern Australia.Mittermeier, R.E. et al. (2002). Wilderness: Earth's last wild places. Mexico City: Agrupación Sierra Madre, ...

. It also occurs in the southern part of New Guinea and on some of the islands to the north of Australia, as far north as the

Maluku Islands The Maluku Islands ( ; , ) or the Moluccas ( ; ) are an archipelago in the eastern part of Indonesia. Tectonics, Tectonically they are located on the Halmahera Plate within the Molucca Sea Collision Zone. Geographically they are located in West ...

of Indonesia. Within its distribution, this semi-arboreal species can be found in a range of habitats, including

coastal dunes A dune is a landform composed of wind- or water-driven sand. It typically takes the form of a mound, ridge, or hill. An area with dunes is called a dune system or a dune complex. A large dune complex is called a dune field, while broad, flat ...

, tropical savannah woodlands, monsoon forests, paperbark

swamp A swamp is a forested wetland.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p. Swamps are considered to be transition zones because both land and water play a role in ...

s and

billabong In Australian English, a billabong ( ) is a small body of water, usually permanent. It is usually an oxbow lake caused by a change in course of a river or creek, but other types of small lakes, ponds or waterholes are also called billabongs ...

s, creeks and riverine environments. In particular, it can be found in the

Arnhem Land tropical savanna The Arnhem Land tropical savanna is a tropical and subtropical grasslands, savannas, and shrublands ecoregion in Australia's Northern Territory. Geography The ecoregion occupies the peninsula of Arnhem Land and its offshore islands, includin ...

, the

Cape York Peninsula tropical savanna The Cape York Peninsula tropical savanna is a tropical grasslands, savannas, and shrublands ecoregion in northern Australia. It occupies the Cape York Peninsula in Queensland, mainland Australia's northernmost point. It is coterminous with t ...

, the

Carpentaria tropical savanna The Carpentaria tropical savanna is a tropical and subtropical grasslands, savannas, and shrublands ecoregion in northern Australia. Geography The ecoregion lies in northwestern Queensland and northeastern Northern Territory, south of the ...

, the

Trans-Fly savanna and grasslands The Trans Fly savanna and grasslands are a lowland ecoregion on the south coast of the island of New Guinea in both the Indonesian and Papua New Guinean sides of the island. With their monsoon and dry season climate these grasslands are quite di ...

, the Victoria Plains tropical savanna, and possibly the

Kimberley tropical savanna The Kimberley tropical savanna is a tropical and subtropical grasslands, savannas, and shrublands ecoregion in northwestern Australia, covering portions of Western Australia and the Northern Territory south of the Timor Sea. Geography The ecore ...

Description

''T. temporalis'' is a slender agamid lizard of moderate size, with long limbs and a long and slender tail. The head is narrow and moderately elongated, with a short rounded snout and a prominent

canthal ridge In snakes and amphibians, the canthus, canthal ridge or ''canthus rostralis''Spawls S, Branch B. 1995. ''The Dangerous Snakes of Africa''. Ralph Curtis Books. Dubai: Oriental Press. 192 pp. . is the angle between the flat crown of the head and the ...

and tympanum. A broad white stripe extends from the tip of the snout, over the lower and upper lips, continuing below the tympanum and down the lateral portion of the body. This stripe tapers off at the hind legs, and it is intersected by three dark bands at the neck, shoulders, and upper back. The portions of the head above and below this stripe are a uniform dark gray or brown color. There is a prominent dorsal crest of enlarged

keeled scales Keeled Scales is an independent record label based in Austin, Texas. It was founded in 2014 by musicians Tony Presley (Real Live Tigers) and Seth Whaland (Literature, Tres Oui). The label has released over 60 albums from artists such as Buck Mee ...

extending from the occiput to the shoulder. This crest continues as a ridge from the shoulder along the spine to the base of the tail. The front legs are darker in color and have more strongly keeled scales than the hind legs. A second, shorter white stripe sometimes extends from the posterior mandible to the area of the temporomandibular joint. The snout-to-vent length is ; hindlimb length is .

Gallery

File:Tropicagama temporalis 188046607.jpg File:Tropicagama temporalis 349756017.jpg File:Tropicagama temporalis 436047848.jpg File:Tropicagama temporalis 159127141.jpg File:Tropicagama temporalis.jpg, At

Fogg Dam Conservation Reserve The Fogg Dam Conservation Reserve is a protected area consisting of a wetland area approximately east of Darwin in the Northern Territory of Australia. It lies within the Adelaide and Mary River Floodplains, which is an Important Bird Area. ...

, Northern Territory, Australia

References

{{Taxonbar, from1=Q77115899, from2=Q3259313 Agamid lizards of Australia Agamidae Monotypic lizard genera Agamid lizards of New Guinea Reptiles of Oceania Reptiles of Queensland Taxa named by Jane Melville Taxa named by Stephanie N.J. Chapple