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Tympanocryptis

January 01, 1970

Tympanocryptis is a genus of Australian lizards in the family Agamidae, commonly known as earless dragons.

Tympanocryptis
Tympanocryptis tetraporophora
Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Iguania
Family: Agamidae
Subfamily: Amphibolurinae
Genus: Tympanocryptis
W. Peters, 1863

Description edit

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 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,[1] Tympanocryptis tetraporophora being an exception.

Species edit

The following 23 species are recognized as being valid.[2][3]

The "grassland earless dragons" edit

Several members of the T. lineata species complex (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. 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 population to actually be an isolated eastern population of T. lineata and the Cooma and Bathurst populations to represent distinct species, and thus restricted the definition of T. pinguicolla to refer to only the possibly-extinct Victorian population.[3]

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 poses one of the most significant threats to them, especially when rocks are disturbed.[5] 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.[3]

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."[5] 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."[6] According to Nelson, they "[m]ay survive short-term disturbance from fire."[5]

In early January 2014, media reported[7] that researchers Professor Stephen Sarre and Dr Lisa Doucette from the University of Canberra'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, Professor Sarre's team won a four-year funding grant from the Australian Research Council 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.[8] 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, overgrazing and climate change.”[9]

References edit

  1. ^ Boulenger GA (1885). Catalogue of the Lizards in the British Museum (Natural History). Second Edition. Volume I. ... Agamidæ. London: Trustees of the British Museum (Natural History). (Taylor and Francis, printers). xii + 436 pp. + Plates I-XXXII. (Genus Tympanocryptis, p. 392).
  2. ^ Tympanocryptis. The Reptile Database. www.reptile-database.org.
  3. ^ a b c d e f Melville Jane; Chaplin Kirilee; Hutchinson Mark; Sumner Joanna; Gruber Bernd; MacDonald Anna J.; Sarre Stephen D. (2019). "Taxonomy and conservation of grassland earless dragons: new species and an assessment of the first possible extinction of a reptile on mainland Australia". Royal Society Open Science. 6 (5): 190233. Bibcode:2019RSOS....690233M. doi:10.1098/rsos.190233. PMC 6549961. PMID 31218062.
  4. ^ a b "Dragons discovered on the Darling Downs". ABC local radio/online. (11 August 2014). accessed same date.
  5. ^ a b c "National Recovery Plan for the Grassland Earless Dragon Tympanocryptis pinguicolla" (PDF). Peter Robertson & Murray Evans. Retrieved 2019-09-27.
  6. ^ Stevens, Evans, Osborne, Sarre (2009). "Home ranges of, and habitat use by, the grassland earless dragon (Tympanocryptis pinguicolla) in remnant native grasslands near Canberra". Australian Journal of Zoology. 58 (2): 76. doi:10.1071/ZO09076.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  7. ^ Canberra breeding program bolsters tiny endangered dragons, Kathleen Dyett, ABC News Online, 3 January 2014, accessed 6 January 2014
  8. ^ New funding gives hope to endangered species, Claudia Doman, University of Canberra, 9 June 2011, accessed 6 January 2014
  9. ^ "Canberra's rare and elusive earless dragon caught on camera". The Riot ACT. 3 March 2019. Retrieved 4 March 2019.

External links edit

  • Tympanocryptis. Zipcode Zoo.
 
Wikispecies has information related to Tympanocryptis.
  • Grassland Earless Dragon.

Further reading edit

  • Peters W (1863). "Eine Übersicht der von Hrn. Richard Schomburgk an das zoologische Museum eingesandten Amphibien, aus Buchsfelde bei Adelaide in Südaustralien ". Monatsberichte der Königlichen Preussischen Akademie der Wissenschaften zu Berlin 1863: 228-236. (Tympanocryptis, new genus, p. 230). (in German).

January 01, 1970
tympanocryptis, genus, australian, lizards, family, agamidae, commonly, known, earless, dragons, tetraporophora, scientific, classification, domain, eukaryota, kingdom, animalia, phylum, chordata, class, reptilia, order, squamata, suborder, iguania, family, ag. Tympanocryptis is a genus of Australian lizards in the family Agamidae commonly known as earless dragons Tympanocryptis Tympanocryptis tetraporophora Scientific classification Domain Eukaryota Kingdom Animalia Phylum Chordata Class Reptilia Order Squamata Suborder Iguania Family Agamidae Subfamily Amphibolurinae Genus TympanocryptisW Peters 1863 Contents 1 Description 2 Species 3 The grassland earless dragons 4 References 5 External links 6 Further readingDescription editThe 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 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 1 Tympanocryptis tetraporophora being an exception Species editThe following 23 species are recognized as being valid 2 3 Tympanocryptis argillosa Melville Chaplin Hipsley Sarre Sumner amp Hutchinson 2019 claypan earless dragon Tympanocryptis centralis Sternfeld 1925 central Australian earless dragon Tympanocryptis cephalus Gunther 1867 blotch tailed earless dragon Tympanocryptis condaminensis Melville et al 2014 Condamine earless dragon previously part of T pinguicolla 4 Tympanocryptis diabolicus Doughty et al 2015 Hamersley pebble mimic dragon Tympanocryptis fictilis Melville Chaplin Hipsley Sarre Sumner amp Hutchinson 2019 Harlequin earless dragon Tympanocryptis fortescuensis Doughty et al 2015 Fortescue pebble mimic dragon Tympanocryptis gigas F Mitchell 1948 Gascoyne pebble mimic dragon Tympanocryptis houstoni Storr 1982 Houston s earless dragon Tympanocryptis intima F Mitchell 1948 gibber earless dragon Tympanocryptis lineata W Peters 1863 lined earless dragon or Canberra grassland earless dragon Canberra population previously part of T pinguicolla 3 Tympanocryptis macra Storr 1982 savannah earless dragon Tympanocryptis mccartneyi Melville et al 2019 Bathurst grassland earless dragon previously part of T pinguicolla 3 Tympanocryptis osbornei Melville et al 2019 Monaro grassland earless dragon previously part of T pinguicolla 3 Tympanocryptis pentalineata Melville et al 2014 five lined earless dragon Tympanocryptis petersi Melville Chaplin Hipsley Sarre Sumner amp Hutchinson 2019 lined earless dragon Tympanocryptis pinguicolla F Mitchell 1948 Victorian grassland earless dragon Tympanocryptis pseudopsephos Doughty et al 2015 Goldfields pebble mimic dragon Tympanocryptis rustica Melville Chaplin Hipsley Sarre Sumner amp Hutchinson 2019 Tennant Creek pebble dragon Tympanocryptis tetraporophora Lucas amp C Frost 1895 long tailed earless dragon Tympanocryptis tolleyi Melville Chaplin Hipsley Sarre Sumner amp Hutchinson 2019 Gawler earless dragon Tympanocryptis uniformis F Mitchell 1948 even scaled earless dragon Tympanocryptis wilsoni Melville et al 2014 Roma earless dragon previously part of T pinguicolla 4 The grassland earless dragons editSeveral members of the T lineata species complex 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 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 population to actually be an isolated eastern population of T lineata and the Cooma and Bathurst populations to represent distinct species and thus restricted the definition of T pinguicolla to refer to only the possibly extinct Victorian population 3 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 poses one of the most significant threats to them especially when rocks are disturbed 5 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 3 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 5 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 6 According to Nelson they m ay survive short term disturbance from fire 5 In early January 2014 media reported 7 that researchers Professor Stephen Sarre and Dr Lisa Doucette from the University of Canberra 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 Professor Sarre s team won a four year funding grant from the Australian Research Council 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 8 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 overgrazing and climate change 9 References edit Boulenger GA 1885 Catalogue of the Lizards in the British Museum Natural History Second Edition Volume I Agamidae London Trustees of the British Museum Natural History Taylor and Francis printers xii 436 pp Plates I XXXII Genus Tympanocryptis p 392 Tympanocryptis The Reptile Database www reptile database org a b c d e f Melville Jane Chaplin Kirilee Hutchinson Mark Sumner Joanna Gruber Bernd MacDonald Anna J Sarre Stephen D 2019 Taxonomy and conservation of grassland earless dragons new species and an assessment of the first possible extinction of a reptile on mainland Australia Royal Society Open Science 6 5 190233 Bibcode 2019RSOS 690233M doi 10 1098 rsos 190233 PMC 6549961 PMID 31218062 a b Dragons discovered on the Darling Downs ABC local radio online 11 August 2014 accessed same date a b c National Recovery Plan for the Grassland Earless Dragon Tympanocryptis pinguicolla PDF Peter Robertson amp Murray Evans Retrieved 2019 09 27 Stevens Evans Osborne Sarre 2009 Home ranges of and habitat use by the grassland earless dragon Tympanocryptis pinguicolla in remnant native grasslands near Canberra Australian Journal of Zoology 58 2 76 doi 10 1071 ZO09076 a href Template Cite journal html title Template Cite journal cite journal a CS1 maint multiple names authors list link Canberra breeding program bolsters tiny endangered dragons Kathleen Dyett ABC News Online 3 January 2014 accessed 6 January 2014 New funding gives hope to endangered species Claudia Doman University of Canberra 9 June 2011 accessed 6 January 2014 Canberra s rare and elusive earless dragon caught on camera The Riot ACT 3 March 2019 Retrieved 4 March 2019 External links editTympanocryptis Zipcode Zoo nbsp Wikispecies has information related to Tympanocryptis Grassland Earless Dragon Further reading editPeters W 1863 Eine Ubersicht der von Hrn Richard Schomburgk an das zoologische Museum eingesandten Amphibien aus Buchsfelde bei Adelaide in Sudaustralien Monatsberichte der Koniglichen Preussischen Akademie der Wissenschaften zu Berlin 1863 228 236 Tympanocryptis new genus p 230 in German Retrieved from https en wikipedia org w index php title Tympanocryptis amp oldid 1161926173, wikipedia, wiki, book, books, library,

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