''Tympanocryptis lineata'', the Canberra grassland earless dragon or lined earless dragon, is a species of
agama found in
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 ...
.
Description
![Tympanocryptis lineata](https://upload.wikimedia.org/wikipedia/commons/d/d5/Tympanocryptis_lineata.jpg)
The Canberra grassland earless dragon is a small, light brown to grey brown lizard usually less than 150 millimetres long and weighing 5–9 grams.
The species has a tapering snout, six or seven dark brown bands on its back, dark speckling on its front (especially the throat), and eleven or fewer dark blotches on its tail.
Some variation in the appearance of individuals in this species is known. For example, spiny scales on the back, and pigmentation of speckles on the front may vary between individuals.
Individuals may exhibit orange-pink colouration on their throat, flanks and sides of head, particularly during the breeding season.
Taxonomy
''Tympanocryptis lineata'' refers to a species of grassland earless dragon found only in a small area of the Australian Capital Territory and New South Wales.
The species was previously grouped with other species including ''
Tympanocryptis pinguicolla
''Tympanocryptis pinguicolla'', also known as Victorian grassland earless dragon, is a species of lizard in the family Agamidae. It is one of a documented species of a relatively small dragon belonging to the genus ''Tympanocryptis''.
Taxonomy ...
'' and what is now described as ''
Tympanocryptis petersi
''Tympanocryptis petersi'', the lined earless dragon, is a species of agama found in South Australia. The specific epithet, ''petersi'', honours Wilhelm Carl Hartwig Peters, who described the genus and type species, ''Tympanocryptis lineata
...
''.
Historically, ‘''Tympanocryptis lineata''’ formed a
species complex. Taxonomic research has led to several species or sub-species previously included under ‘''Tympanocryptis lineata''’ now being reclassified or described as new species, including:
* ''
Tympanocryptis argillosa''
* ''
Tympanocryptis centralis
''Tympanocryptis centralis'', also known as central Australian earless dragon or central pebble dragon, is one of a documented species of a relatively small dragon belonging to the genus ''Tympanocryptis
''Tympanocryptis'' is a genus of Austr ...
''
* ''
Tympanocryptis fictilis''
* ''
Tympanocryptis houstoni
''Tympanocryptis houstoni'', also known as Houston's earless dragon or Nullarbor earless dragon, is one of a documented species of a relatively small dragon belonging to the genus ''Tympanocryptis''.
Habitat
This terrestrial species is found i ...
''
* ''Tympanocryptis lineata''
* ''
Tympanocryptis macra
''Tympanocryptis macra'', the savannah earless dragon, is a species of agama found in northernWestern Australia and the Northern Territory. It was described originally as ''Tympanocryptis lineata'' ''macra'' in 1982 by Glen Milton Storr.Storr, G ...
''
* ''
Tympanocryptis osbornei
''Tympanocryptis osbornei'', the Monaro grassland earless dragon, is a species of agama found in Australia
Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Aust ...
''
* ''
Tympanocryptis petersi
''Tympanocryptis petersi'', the lined earless dragon, is a species of agama found in South Australia. The specific epithet, ''petersi'', honours Wilhelm Carl Hartwig Peters, who described the genus and type species, ''Tympanocryptis lineata
...
''
* ''
Tympanocryptis pinguicolla
''Tympanocryptis pinguicolla'', also known as Victorian grassland earless dragon, is a species of lizard in the family Agamidae. It is one of a documented species of a relatively small dragon belonging to the genus ''Tympanocryptis''.
Taxonomy ...
''
* ''
Tympanocryptis rustica''
* ''
Tympanocryptis tolleyi
''Tympanocryptis tolleyi'', the Gawler earless dragon, is a species of Agamidae, agama found in South Australia.
References
Agamid lizards of Australia
Endemic fauna of Australia
Reptiles described in 2019
Reptiles of South Australia
Tax ...
''
Morphologically, the
homogeneity
Homogeneity and heterogeneity are concepts often used in the sciences and statistics relating to the uniformity of a substance or organism. A material or image that is homogeneous is uniform in composition or character (i.e. color, shape, siz ...
of scales on the thighs of the Canberra grassland earless dragon is one characteristic that may differentiate this species from other similar species.
However, external morphological characteristics are often inadequate in identifying to species level. Recent taxonomic reclassification has come about through the use of modern techniques including
phylogeography and
phylogenomics
Phylogenomics is the intersection of the fields of evolution and genomics. The term has been used in multiple ways to refer to analysis that involves genome data and evolutionary reconstructions. It is a group of techniques within the larger field ...
''.''
Distribution
![RangeMap T lineata](https://upload.wikimedia.org/wikipedia/commons/b/bc/RangeMap_T_lineata.jpg)
The Canberra grassland earless dragon has a very narrow distribution, being found only in a small area of the
Australian Capital Territory
The Australian Capital Territory (commonly abbreviated as ACT), known as the Federal Capital Territory (FCT) until 1938, is a landlocked federal territory of Australia containing the national capital Canberra and some surrounding townships. ...
and
New South Wales
)
, nickname =
, image_map = New South Wales in Australia.svg
, map_caption = Location of New South Wales in AustraliaCoordinates:
, subdivision_type = Country
, subdivision_name = Australia
, established_title = Before federation
, es ...
. Populations have been detected at locations within 13 kilometres of Canberra Airport.
Its geographical distribution does not overlap with any other earless dragon species, and as such the Canberra grassland earless dragon is considered to be geographically isolated.
Ecology and habitat
Canberra grassland earless dragons inhabit
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 ...
characterised by tussocks with open space, few or no trees and shrubs and minimal pasture. They prefer well-drained sites dominated by tall speargrass (genus ''
Austrostipa'') and shorter wallaby grass (genus ''
Austrodanthonia'').
They eat a range of
invertebrates
Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...
including ants, beetles, spiders, moths and moth larvae.
The species is thought to utilise existing
arthropod
Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a Segmentation (biology), segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and Arth ...
burrows for shelter in order to endure extreme temperatures experienced in its habitat.
Reproduction and longevity
Females usually produce only one clutch of between three and seven eggs (most commonly around four eggs).
Clutches are produced in spring, with a second clutch produced in summer if conditions are favourable.
Canberra grassland earless dragons can live several years in captivity but are generally short-lived in the wild.
Threats and conservation
The Canberra grassland earless dragon is at high risk of extinction.
Population size was declining gradually and more recently a dramatic decline in population size has been observed, and the species has become undetectable in some places.
A low annual survival rate for juvenile and adult individuals may contribute to the decline of this species.
Key threats to this species include a reduction in grassland areas due to urban and other development,
habitat fragmentation
Habitat fragmentation describes the emergence of discontinuities (fragmentation) in an organism's preferred environment (habitat), causing population fragmentation and ecosystem decay. Causes of habitat fragmentation include geological processes ...
,
predation
Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the ...
, altered grazing regimes, altered fire regimes, weed invasion 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 ...
.
The Canberra grassland earless dragon is not listed as a threatened species in the
Australian Capital Territory
The Australian Capital Territory (commonly abbreviated as ACT), known as the Federal Capital Territory (FCT) until 1938, is a landlocked federal territory of Australia containing the national capital Canberra and some surrounding townships. ...
,
New South Wales
)
, nickname =
, image_map = New South Wales in Australia.svg
, map_caption = Location of New South Wales in AustraliaCoordinates:
, subdivision_type = Country
, subdivision_name = Australia
, established_title = Before federation
, es ...
,
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 ...
or the
IUCN Red List
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biol ...
. However, the
Victorian grassland earless dragon (which was previously grouped with the Canberra grassland earless dragon) is listed as endangered. The apparent omission of the Canberra grassland earless dragon on threatened species lists is considered to be an administrative issue due to the recent taxonomic reclassification of this species.
Current conservation and rehabilitation efforts in the
Australian Capital Territory
The Australian Capital Territory (commonly abbreviated as ACT), known as the Federal Capital Territory (FCT) until 1938, is a landlocked federal territory of Australia containing the national capital Canberra and some surrounding townships. ...
are aimed at earless dragon species including the Canberra grassland earless dragon. A captive breeding facility for Canberra grassland earless dragons opened at
Tidbinbilla Nature Reserve in 2021.
The facility aims to maintain a captive breeding population of genetically diverse individuals for observation and eventual release.
Other conservation efforts include habitat restoration and climate risk assessments to understand the viability of future habitats and release sites.
References
lineata
Agamid lizards of Australia
Endemic fauna of Australia
Reptiles of New South Wales
Taxa named by Wilhelm Peters
Reptiles described in 1863
{{agamidae-stub