Presumed Extinct Sea Snake Reappears Off Australia
It's the creature's first appearance in more than 15 years.
A pair of sea snakes considered extinct has suddenly appeared off the coast of Western Australia, according to a study by researchers from James Cook University (JCU).
The scientists say it has been more than 15 years since the short-nosed sea snake was last spotted -- in the waters of Ashmore Reef, in the Timor Sea
The sea snakes were first observed by a Western Australia Parks and Wildlife officer, who took pictures of the long-forgotten marine reptiles on Ningaloo Reef and shared them with JCU's Blanche D'Anastasi, lead author of the study.
"We were blown away," said D'Anastasi in a release. "These potentially extinct snakes were there in plain sight, living on one of Australia's natural icons, Ningaloo Reef."
The news got even better for researchers, when it seemed that there was love in the water.
"What is even more exciting is that they were courting, suggesting that they are members of a breeding population," D'Anastasi said.
The short-nosed sea snake is formally listed as Critically Endangered on the International Union for Conservation of Nature's "red list" of threatened species and is protected under Australian law.
Researchers are not yet sure what caused the snakes to disappear from the Ashmore Reef, though the IUCN listing suggests coral bleaching may have played a part.
The JCU researchers also got good news about another critically endangered sea snake, when a sizable population of the rare leaf-scaled sea snake was found in the waters of Shark Bay.
"This discovery is really exciting," said D'Anastasi of the finds. "We get another chance to protect these two endemic Western Australian sea snake species."
"But in order to succeed in protecting them," she added, "we will need to monitor populations as well as undertake research into understanding their biology and the threats they face."
The researchers' findings have been published in the journal Biological Conservation.
Shown is a photograph of a pair of short-nosed sea snakes, rediscovered on Ningaloo Reef off Western Australia.
The world's first known snake has just been discovered in Brazil, according to new research that solves many mysteries about the slithering reptiles. The snake (
), described in the latest issue of the journal Science, is also the first known snake to have four limbs. This strongly suggests that snakes evolved from terrestrial lizards, and not from water-dwelling species, as had been thought before. "The marine hypothesis is dead," senior author Nicholas Longrich of the University of Bath told Discovery News. "It's actually been pretty dead for a while now, but this is really pounding the nails in the coffin. Aquatic snakes evolved from terrestrial snakes -- many, many times." As this image shows,
aka "Four Feet" was a meat-eating predator. It lived in what is now the Crato Formation of Ceará, Brazil, between 146 and 100 million years ago.
If Four Feet could be brought back to life today, "You would be confused, because you would be thinking that this looks like a snake...but it's odd; it shouldn't have feet," lead author David Martill of the University of Portsmouth told Discovery News. He, Longrich, and co-author Helmut Tischlinger believe that the unusual reptile and its kin evolved ever-smaller limbs after their predecessors went through a subterranean phase. During this period of the Early Cretaceous, the animals burrowed underground. "Limbs get in the way if you are burrowing through soft sand," Martill explained. "Much better to 'swim' through leaf litter or sand. As legs got smaller, 'swimming' became more efficient." The scientists further suspect that these undulating movements were pre-adaptations to actual swimming in water.
Four Feet's front limbs were so small that Martill described them as being "pathetic" and "little." While miniscule, the feet seemed to be specialized, as they were broader than those of lizards. As a result, the researchers think the feet helped the snake to seize prey and clasp onto a partner when mating.
Four Feet's head was slightly pointed and slender, suggests its skull. As for its overall appearance, "It looked, well, snaky," Longrich said. "It had the long, slender, serpentine body; it would have had a forked tongue," he continued. "It had the broad belly scales of a snake. This is unique to snakes, and amazingly the fossil actually preserves them." The individual died while young and was only about 8 inches long. The scientists are not sure how big members of the species would have become as adults, but they suspect that adults grew to be over 3 feet long.
The remains of an unknown animal -- possible a lizard -- are remarkably preserved in the gut of the fossilized snake. Based on Four Feet's build, it probably bit its victims and then squeezed them, cutting off their circulation. Organ failure probably followed and then death. The gut contents also indicate that the snake had a feeding strategy similar to today's boa constrictors "in which proportionately large prey are ingested whole," the authors wrote.
The serpentine fossil for Four Feet is extremely well preserved in limestone. It is in such good condition that "soft tissues are also preserved," according to the authors. The snake would have lived in an ecosystem with dinosaurs, they indicated. While this juvenile snake might have eaten small dinosaur eggs, it is possible that adults of the species "could take a hatchling dinosaur," Martill said. Longrich added that 40-50 million years after this snake's lifetime, there were large boa and python-sized snakes that definitely were regular consumers of dinosaur eggs. Remains of snakes are even found in dinosaur nests as a result. Poisonous snakes were not around then, though. They did not become widespread until about 34 million years ago, which was long after non-bird dinosaurs went extinct. The burrowing habits of early snakes might have helped to save them from going the way of the dinos during the major extinction event 65 million years ago.
In addition to lizards like
, Four Feet probably ate salamanders and other small animals, the researchers believe. Both the ancient snake and its prey were "originally from Gondwana, the ancient continent formed by Africa and South America," Longrich said. As he says, "They're sort of a holdover from this lost world."