The inland taipan (Oxyuranus microlepidotus), also commonly known as the western taipan, small-scaled snake, or fierce snake,White, Julian (November 1991). a new window Oxyuranus microlepidotus. "Neurotoxic paralysis usually takes 2–4 hours to become clinically detectable. Coagulopathy however may become well established within 30 minutes of a bite." International Programme on Chemical Safety. Retrieved 8 November 2013. is a species of extremely venomous snake in the family Elapidae. It is endemic to semiarid regions of central‑eastern Australia.Cecilie Beatson (29 November 2011). a new window Animal Species: Inland Taipan. Australian Museum. Retrieved 14 October 2013. Aboriginal Australians living in areas where Karnic languages are spoken refer to this species as dandarabilla.Queensland Snakes. a new window History & Discovery. (archived) Queensland Museum. Retrieved 15 November 2013.
The species was formally described by Frederick McCoy in 1879 and William John Macleay in 1882, but for almost 90 years, it remained poorly known to science; no additional specimens were collected and virtually nothing was added to knowledge of its biology until the species was rediscovered in 1972.Rediscovery. a new window the rediscovery of the western taipan. (archived) Queensland Museum. Retrieved 15 November 2013.
Based on the median lethal dose (LD50) of its venom in laboratory mice, the inland taipan is widely regarded as the most venomous snake in the world; its venom is substantially more toxic, drop-for-drop, than that of any tested sea snake. The Australian venom research unit (25 August 2007) "Which snakes are the most venomous?" . University of Melbourne. Retrieved 14 October 2013. Venom Immunochemistry, Pharmacology and Emergency Response (VIPER) Institute Frequently Asked Questions -What is the most venomous snake? . "Many experts answer that it is the Inland Taipan of Australia, because its drop-by-drop concentration of venom has great potency when measured by its ability to kill rodents". University of Arizona. Retrieved 14 October 2013. Department of Wildlife Ecology and Conservation Frequently Asked Questions About Venomous Snakes. "A comparative study found that the snake venom that is most toxic to mice (of the species tested) is that of the Inland Taipan (Oxyuranus microlepidotus), found in Australia". University of Florida. Retrieved 5 November 2013.
It is also considered to possess the most toxic venom of any reptile when tested on human heart cell cultures.a new window Fry, Bryan (8 February 2005) a new window Most Venomous . "Q: I was wondering what snake's venom is the most potent to humans. A: Drop for drop it is the inland taipan (Oxyuranus microlepidotus), which has a venom more toxic than any other land snake or even the sea snakes." venomdoc.com forums. Retrieved 17 April 2014.Seymour, Jamie, a new window World's Worst Venom, (min 44:33) "Among the reptiles tested, the most toxic venom belongs to inland taipan, killing over 60% of heart cells in the first 10 minutes." National Geographic Channel. Retrieved 17 April 2014.Seymour, Jamie, a new window Venom Death Match. "They have the most toxic venom towards humans than any other snake in the world" (min 1:49). National Geographic Channel. Retrieved 17 April 2014. The inland taipan is a specialised predator of mammals, and its venom is particularly adapted to killing warm-blooded prey. A single bite has been estimated to contain sufficient venom to kill more than 100 adult humans.* Journal of Herpetology Vol.17 no.1 (1983) Ecology of Highly Venoumous Snakes: the Australian Genus Oxyuranus. "..the number of mouse LD50 doses per bite is much higher for Oxyuranus microlepidotus (218,000 mice)...than for any other snakes, including sea snakes, investigated to date (Broad, Sutherland and Coulter, 1979)." (page 1) University of Sydney. Retrieved 8 November 2013. "Reptiles – Fierce Snake" . Australia Zoo. Retrieved 14 October 2013. Martin, Stella (January 2004). Newsletter No. 80. "It has been calculated that there is enough venom in just one bite of an Inland taipan to kill more than 100 men of average size." Environmental Protection Agency (Queensland). Retrieved 18 October 2013. News (28 September 2012) Meet the world's deadliest snake in safety , Taronga Conservation Society. Retrieved 23 September 2014
Despite this extreme potency, the inland taipan is usually shy and reclusive, with a generally placid disposition,* Cecilie Beatson (29 November 2011). Animal Species: Inland Taipan "The venom of the Inland Taipan is extremely potent and is rated as the most toxic of all snake venoms in LD50 tests on mice". Australian Museum. Retrieved 14 October 2013. South Australia Arid Lands Natural Resources Management Board Biodiversity studies, Student fact sheet . Government of South Australia. Retrieved 15 October 2013. Clinical Toxinology Resources "Oxyuranus microlepidotus -General Details, Taxonomy and Biology, Venom, Clinical Effects, Treatment, First Aid, Antivenoms". University of Adelaide. Retrieved 14 October 2013. ABC News 24 (28 September 2012). 'Placid' taipan in safe hands. (Quoting licensed reptile handler, Judith {Judy} Martin). Australian Broadcasting Corporation. Retrieved 13 November 2013. and it rarely comes into contact with people because it inhabits remote areas. By contrast, the coastal taipan (Oxyuranus scutellatus) is often considered the more dangerous species in practice, largely because of its behaviour when it encounters humans and its proximity to populated coastal regions. The word "fierce" in one of the inland taipan's common names refers to the strength of its venom rather than its temperament.Threatened species 10 October 2012. Fierce Snake – profile. Office of Environment and Heritage (New South Wales). Retrieved 15 October 2013.
Taxonomy
Among the Aboriginal people from the area now known as Goyder Lagoon in north‑eastern South Australia, the inland taipan was traditionally known as dandarabilla.
The inland taipan was first described scientifically in 1879, when two specimens were collected at the junction of the Murray and Darling Rivers in north‑western Victoria. Frederick McCoy described these as Diemenia microlepidota, the "small‑scaled brown snake". In 1882 a third specimen was collected near Bourke, New South Wales, and William John Macleay described it as Diemenia ferox, believing it to be a different species.Kinghorn, J. Roy (1 September 1955). Herpetological notes. No. 5 (page 284). Australian Museum Scientific Publications. Retrieved 14 November 2013. No further material was collected until the 1967.
In 1896, George Albert Boulenger transferred both taxa to the genus Pseudechis (black snakes), treating them as Pseudechis microlepidotus and P. ferox. In 1956, working solely from the published descriptions and notes, James Roy Kinghorn regarded ferox as a synonym of microlepidotus and proposed the new genus Parademansia for the species.
In 1963, Eric Worrell considered Parademansia microlepidotus conspecific with Oxyuranus scutellatus (then commonly known simply as the "taipan"). However, in September 1972 an unclassified snake head collected by a grazier on a Channel Country station west of Windorah in south‑western Queensland was sent to the Queensland Museum. Herpetologists Jeanette Covacevich and Charles Tanner travelled to the site, located 13 live specimens, and thereby rediscovered the long‑lost "western taipan" Parademansia microlepidotus.
In 1976, Covacevich and Wombey argued that Parademansia microlepidotus was sufficiently distinct to warrant generic recognition, a view shared by Harold Cogger. Subsequently, Covacevich, McDowell, Tanner and Mengden (1981) compared anatomical characters, chromosomes, and behaviour of the two then‑recognised species Oxyuranus scutellatus and Parademansia microlepidota and concluded that both belonged in a single genus. The older name Oxyuranus (erected in 1923), therefore, had priority and was adopted for the combined genus.Two Taipans. Two Taipans - Coastal and Western. (archived) Queensland Museum. Retrieved 15 November 2013.Covacevich, J., McDowell, S.B., Tanner, C. & Mengdon, G. (Aust. Herp. Symposium, 1980). The relationship of the taipan (Oxyuranus scutellatus) and the small-scaled snake (O. microlepidotus), Serpentes: Elapidae (page 32). kingsnake.com. Retrieved 15 November 2013.
The current binomial name of the inland taipan has therefore been Oxyuranus microlepidotus since the early 1980s. The generic name Oxyuranus derives from the Greek oxys ("sharp" or "needle‑like") and ouranos ("arch", specifically the arch of the palate), referring to the needle‑like anterior process on the palatal arch.Meagher, David (2012). "An etymology of the scientific names of Victorian snakes". The Victorian Naturalist. 129 (1): 54–60. The specific epithet microlepidotus is from Latin and means "small‑scaled", referring to the small body scales, and is the origin of the common name "small‑scaled snake".Welton, Ronelle Ellen (2005) PhD thesis. Proteomic and genomic characterisation of venom proteins from Oxyuranus species. (microlepidotus). James Cook University. Retrieved 15 November 2013.
Once Covacevich et al. (1981) had shown that the fierce snake (formerly Parademansia microlepidota) belonged to the genus Oxyuranus, the name "taipan" (derived from the Aboriginal term dhayban) was retained for O. scutellatus, which became known as the coastal taipan (or "eastern taipan"), while O. microlepidotus came to be widely referred to as the "inland (or western) taipan").
Distribution and habitat
The inland taipan occurs on cracking‑clay plains in semiarid regions near the border of Queensland and South Australia.Threatened species (10 October 2012). a new window Fierce Snake – profile. Office of Environment and Heritage (New South Wales). Retrieved 16 October 2013.
In Queensland, the species has been recorded from the Channel Country bioregion,Wildlife of Channel Country (CHC) bioregion. (western taipan) Department of Environment and Heritage Protection (Queensland). Retrieved 10 November 2013. including Diamantina National Park, Durrie Station, Morney Plains StationDesert Channels region Natural resource management. Desert Channels Queensland's Biodiversity Plan . (Channel country, page 24 /special fauna areas) Government of Queensland. Retrieved 10 November 2013. and Astrebla Downs National Park.Wildlife of Astrebla Downs National Park. (western taipan) Department of Environment and Heritage Protection (Queensland). Retrieved 10 November 2013. In South Australia it has been observed in the Marree–Innamincka NRM district,South Australia arid lands natural resources management board. Birdsville Strzelecki - Legendary tracks of the Marree Innamincka District. (Archived) (map of district on second page) (Inland taipan page 7) Government of South Australia. Retrieved 10 November 2013.South Australia arid lands natural resources management board. Marree – Innamincka Natural Resources Management Group (Archived). Government of South Australia. Retrieved 10 November 2013. including Goyder Lagoon,Toxicon journal (January 1999) The smooth muscle relaxant effects of venom from the inland taipan (Oxyuranus microlepidotus). (page 1) ResearchGate. Retrieved 10 November 2013. the Tirari Desert, Sturt Stony Desert, Coongie Lakes, Innamincka Regional Reserve and near Oodnadatta.(Last updated: 19 July 2013). SAAL Regional Species Conservation Assessment Project (PDF sheet download, pages 50, 67). Department of Environment, Water and Natural Resources (South Australia). Retrieved 8 November 2013. An isolated population is also known from near Coober Pedy, South Australia.South Australia arid lands natural resources management board. Biodiversity studies, Student fact sheet . Government of South Australia. Retrieved 15 October 2013.