These sea snakes are descended from Australian land snakes, the latter with a reputation of being the most overall venomous in the world.[*] In turn, the reason for the latter is that they originated from invasive Asian Elapidae stock, which had no toxic competitors when they reached the remote continent. Thereby soon diversifying across it, but some even mutating toward being non-poisonous. Aspidites already occupied Australia, but they're not venomous reptiles and were arguably restricted to narrower habitat.
- - - footnote - - - [*] Australian experts have been known to counter that this is a pop-market misconception originating from faulty LD50 research (Statistics and the LD50 study?). They contend that Africa and South America have more species of poisonous snakes, with higher grades of toxicity.
Dorset man killed by sea snake in Australia
https://www.bbc.com/news/uk-england-dorset-45779688
EXCERPT: A British man who died after being bitten by a sea snake in Australia was "living his dream" working on a fishing boat, his mother said. Harry Evans, 23, from Poole, Dorset, was bitten while working on a trawler off the coast of the Northern Territory on Thursday. Emergency crews were called to the boat, near island Groote Eylandt, but were unable to save him....
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- - - footnote - - - [*] Australian experts have been known to counter that this is a pop-market misconception originating from faulty LD50 research (Statistics and the LD50 study?). They contend that Africa and South America have more species of poisonous snakes, with higher grades of toxicity.
Dorset man killed by sea snake in Australia
https://www.bbc.com/news/uk-england-dorset-45779688
EXCERPT: A British man who died after being bitten by a sea snake in Australia was "living his dream" working on a fishing boat, his mother said. Harry Evans, 23, from Poole, Dorset, was bitten while working on a trawler off the coast of the Northern Territory on Thursday. Emergency crews were called to the boat, near island Groote Eylandt, but were unable to save him....
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