An experiment has shown green sea turtle embryos are much more likely to die when they are inside eggs that go underwater for six hours.

Scientists say the study shows the turtles, which rely on low-lying coastal habitats, are likely to feel the early impacts of rising sea levels.

"In some places it only takes a small rise in sea levels, when combined with a storm or a king tide, to inundate what had previously been secure nesting sites," said lead researcher Dr David Pike of James Cook University.

Scientists have welcomed the first results of a captive breeding program aimed at saving a group of critically endangered Fijian crested iguanas, the first such attempt to reintroduce a species in that country.

Some of the iguanas that were introduced to the Fijian island of Monuriki two months ago have been tracked down by scientists and appear to be healthy.

A total of 32 iguanas were microchipped and released, with tiny radio transmitters glued to the tails of 11 for tracking purposes. Nine were recovered on Sunday.

US Geological Survey biologist Robert Fisher reported all had increased in length and lost their excessive weight. A lean diet of native plants had evidently “sorted them out,” he said. There was no evidence of trauma or other health issues.

The bulk of his hospital bill — $83,000 of it — is due to pharmacy charges. Specifically, charges for the antivenin used to treat the bite. KGTV reports that Fassler depleted the antivenin supplies at two local hospitals during his five-day visit. Nobody expects antivenin to be cheap. But $83,000?

There's currently only one commercially available antivenin for treating venomous snakebites in the United States -- CroFab, manufactured by U.K.-based BTG plc. And with a stable market of 7,000 to 8,000 snakebite victims per year and no competitors, business is pretty good. BTG's latest annual report shows CroFab sales topped out at close to 63 million British pounds, or $98 million dollars, last fiscal year. The antivenin costs hospitals roughly $2,300 per vial, according to Bloomberg, with a typical dose requiring four to six vials. In some cases multiple doses are needed, according to CroFab's promotional Web site.

BTG has fought aggressively to keep competitors off the market. A competing product, Anavip, just received FDA approval this year and likely won't be on the market until late 2018. This lack of competition is one reason that snakebite treatments rack up such huge hospital bills -- $55,000. $89,000. $143,000. In May of this year, a snakebit Missouri man died after refusing to seek medical care, saying he couldn't afford the bill.

The roughly 120 million-year-old snake, dubbed Tetrapodophis amplectus (literally, four-legged snake), likely didn't use its feet for walking. Instead, the appendages may have helped Tetrapodophis hold onto a partner while mating, or even grip unruly prey, said study co-researcher David Martill, a professor of paleobiology at the University of Portsmouth in the United Kingdom.

Previous research has detailed two-legged snake fossils, but this is the first known snake ancestor to sport four legs, he said. It likely evolved from terrestrial-burrowing creatures, and was a transitional animal that lived during the shift from ancient lizards to modern-day snakes, he added.