''Tympanocryptis'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

n lizards in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Agamidae Agamidae is a family (biology), family of over 300 species of iguanian lizards indigenous to Africa, Asia, Australia, and a few in Southern Europe. Many species are commonly called dragons or dragon lizards. Overview phylogenetics, Phylogenetic ...

commonly known as earless dragons.

Description

The genus ''Tympanocryptis'' has the following characters. The tympanum is hidden (hence the common name earless dragon). The body is depressed, and it is covered

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

with heterogeneous scales. There is no dorsal crest. There is no gular sac, but a strong transverse gular fold is present. The tail is round in cross section. There is a preanal pore on each side, which sometimes is absent in females. In most species there are no femoral pores, ''

Tympanocryptis tetraporophora ''Tympanocryptis tetraporophora'', also known as Eyrean earless dragon or long-tailed earless dragon, is one of a documented species of a relatively small dragon belonging to the genus ''Tympanocryptis''. ''Tympanocryptis'' is differentiated from ...

'' being an exception.

Species

The following 23

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

are recognized as being valid. *'' Tympanocryptis argillosa'' – claypan earless dragon *'' Tympanocryptis centralis'' – central Australian earless dragon *'' Tympanocryptis cephalus'' – blotch-tailed earless dragon *'' Tympanocryptis condaminensis'' – Condamine earless dragon (previously part of ''T. pinguicolla'')"Dragons discovered on the Darling Downs"
ABC local radio/online. (11 August 2014). accessed same date. *'' Tympanocryptis diabolicus'' – Hamersley pebble-mimic dragon *'' Tympanocryptis fictilis'' – Harlequin earless dragon *'' Tympanocryptis fortescuensis'' – Fortescue pebble-mimic dragon *'' Tympanocryptis gigas'' – Gascoyne pebble-mimic dragon *'' Tympanocryptis houstoni'' – Houston's earless dragon *'' Tympanocryptis intima'' –

gibber A desert pavement, also called reg (in the western Sahara), serir (eastern Sahara), gibber (in Australia), or saï (central Asia) is a desert surface covered with closely packed, interlocking angular or rounded rock fragments of pebble and cobbl ...

earless dragon *'' Tympanocryptis lineata'' – lined earless dragon or Canberra grassland earless dragon (Canberra population previously part of ''T. pinguicolla'') *'' Tympanocryptis macra'' () – savannah earless dragon *'' Tympanocryptis mccartneyi'' – Bathurst grassland earless dragon (previously part of ''T. pinguicolla'') *'' Tympanocryptis osbornei'' – Monaro grassland earless dragon (previously part of ''T. pinguicolla'') *'' Tympanocryptis pentalineata'' – five-lined earless dragon *'' Tympanocryptis petersi'' – lined earless dragon *'' Tympanocryptis pinguicolla'' – Victorian grassland earless dragon (possibly

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

) *'' Tympanocryptis pseudopsephos'' – Goldfields pebble-mimic dragon *'' Tympanocryptis rustica'' – Tennant Creek pebble dragon *''

'' – long-tailed earless dragon *'' Tympanocryptis tolleyi'' – Gawler earless dragon *'' Tympanocryptis uniformis'' – even-scaled earless dragon *'' Tympanocryptis wilsoni'' – Roma earless dragon (previously part of ''T. pinguicolla'')

The "grassland earless dragons"

Several members of the ''T. lineata''

species complex In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

(namely the Canberra population of ''T. lineata, T. mccartneyi'', ''T. osbornei'', and ''T. pinguicolla'') are referred to as the "grassland earless dragons", being the only members of the family Agamidae to be restricted to natural

temperate grasslands Temperate grasslands, savannas, and shrublands is a terrestrial biome defined by the World Wide Fund for Nature. The predominant vegetation in this biome consists of grass and/or shrubs. The climate is temperate and ranges from semi-arid to semi ...

. These species are found at higher altitudes and in regions that have cooler temperatures than any other earless dragon, where they prefer sites with both taller tussock and shorter grasses. The species were formerly considered different isolated populations of ''T. pinguicolla'', until a 2019 study found the

Canberra Canberra ( ) is the capital city of Australia. Founded following the federation of the colonies of Australia as the seat of government for the new nation, it is Australia's largest inland city and the eighth-largest city overall. The ci ...

population to actually be an isolated eastern population of ''T. lineata'' and the

Cooma Cooma is a town in the south of New South Wales, Australia. It is located south of the national capital, Canberra, via the Monaro Highway. It is also on the Snowy Mountains Highway, connecting Bega with the Riverina. At the , Cooma had a po ...

and Bathurst populations to represent distinct species, and thus restricted the definition of ''T. pinguicolla'' to refer to only the possibly-extinct

Victorian Victorian or Victorians may refer to: 19th century * Victorian era, British history during Queen Victoria's 19th-century reign ** Victorian architecture ** Victorian house ** Victorian decorative arts ** Victorian fashion ** Victorian literature ...

population. The grassland earless dragons lay 3-6 eggs in late spring or early summer. Their young hatch in late summer (possibly disperse soon after hatching), grow to adult size rapidly (by late autumn-early winter), mate the following spring, and often die within one year of birth. They can reach the age of 5 within captivity. All of the grassland earless dragons are highly endangered due to the heavy destruction and conversion of the temperate grasslands, of which less than 1% are said to remain.

Overgrazing Overgrazing occurs when plants are exposed to intensive grazing for extended periods of time, or without sufficient recovery periods. It can be caused by either livestock in poorly managed agricultural applications, game reserves, or nature res ...

poses one of the most significant threats to them, especially when rocks are disturbed. These species are rarely found outside native temperate grasslands, and does not adapt well to changed environments, primarily due to the lack of food diversity found outside their native habitat. ''T. pinguicolla'' may already be extinct due to the heavy degradation that grasslands have received in Victoria, with the last known confirmed sighting being made in 1969. According to herpetologist Lyn S. Nelson, "Observations indicate that arthropod burrows, surface rocks, or other similar refuge sites may be necessary for the continued persistence of populations of dragons, by providing thermal refugia." They are known to hide within abandoned arthropod burrows and underneath rocky outcrops in order to lay eggs and protect themselves from predators. Soil disturbance, such as ploughing or compaction, might also result in destruction of the essential arthropod burrows and possibly a reduction in the abundance, at least in the short-term, of burrow forming arthropods. A radio-tracking study found that "burrows excavated by arthropods are an important resource for grassland earless dragons, with individuals having one or two home burrows around which they maintained home ranges of between 925 m² and 4768 m²." According to Nelson, they " y survive short-term disturbance from fire." In early January 2014, media reported that researchers Professor Stephen Sarre and Dr Lisa Doucette from the

University of Canberra The University of Canberra (UC) is a public research university with its main campus located in Bruce, Canberra, Australian Capital Territory. The campus is within walking distance of Westfield Belconnen, and from Canberra's Civic Centre. UC ...

's Institute for Applied Ecology had succeeded in breeding the Canberran ''T. lineata'' in captivity, and had also hatched eggs gathered from field studies, with around 60 hatchlings being born. In June 2011, Professo
Sarre
s team won a four-year funding grant from the

Australian Research Council The Australian Research Council (ARC) is the primary non-medical research funding agency of the Australian Government, distributing more than in grants each year. The Council was established by the ''Australian Research Council Act 2001'', ...

to research and potentially save the species from extinction, and find a cause for the species recent collapse in numbers, thought to be associated with 10 years of drought in the species' range.New funding gives hope to endangered species
Claudia Doman,

, 9 June 2011, accessed 6 January 2014 In 2019, ecologist Brett Howard from the ACT Parks and Conservation Service said that "grassland earless dragons are at risk of extinction in the near future even though much has been done to improve their survival chances in the past five years." He then listed the threats posed to this species, saying "this species has suffered declines in recent decades likely due to a combination of

drought A drought is defined as drier than normal conditions.Douville, H., K. Raghavan, J. Renwick, R.P. Allan, P.A. Arias, M. Barlow, R. Cerezo-Mota, A. Cherchi, T.Y. Gan, J. Gergis, D. Jiang, A. Khan, W. Pokam Mba, D. Rosenfeld, J. Tierney, an ...

, overgrazing and

climate change In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...

.”

References

External links

''Tympanocryptis''
Zipcode Zoo.
Grassland Earless Dragon

Description

Species

The "grassland earless dragons"

References

External links

Further reading