Clinton & Charles Robertson, Wikimedia Commons
Timber rattlesnake populations are in trouble.
Julius T. Cstonyi
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.What the First Snake Looked Like
Dave Martill, University of Portsmouth
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.Video: How Snakes Got Their Venom
Dave Martill, University of Portsmouth
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.How Snakes Lost Their Legs
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.Top 12 Most Amazing Snakes
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.Boa Constrictors Don't Suffocate Prey, They Use Better Method
Dave Martill, University of Portsmouth
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.Earliest Known Snakes Slithered Around Dinosaurs
James Brown, University of Portsmouth
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."Boa Constrictor Mom Gives Virgin Birth
Conservationists in Massachusetts plan to establish a population of native venomous timber rattlesnakes on an uninhabited island, according to the state’s Division of Fisheries and Wildlife (MassWildlife).
Locals are so alarmed by the idea that officials are holding a public meeting on Tuesday to present their case and address concerns.
“Not only has the timber rattlesnake declined in Massachusetts and throughout New England, it is now completely extirpated from Maine and Rhode Island,” according to the MassWildlife statement. “Humans are the greatest threat to (the) timber rattlesnake. In Massachusetts, the timber rattlesnake has lived continuously since long before European settlement, and has persisted in the face of sometimes intense persecution, but its decline over the past 30 years has been more severe than (at) any other time in history.”
Tom French, assistant director of MassWildlife’s Natural Heritage and Endangered Species program, and his colleagues propose to establish a small group of the rattlesnakes on Mount Zion, which is a large island closed to public access at the Quabbin Reservoir located in central Massachusetts. The reservoir is owned and managed by the Department of Conservation and Recreation’s Division of Water Supply Protection.
The plan is to raise juvenile snakes from Massachusetts in captivity by the Roger Williams Zoo in Providence, R.I. After about two years they grow to a size that deters predators, and the young snakes would then be released on the island. French and his team say that only between one and 10 of the timber rattlesnakes would be released in any given year.
To ease worried minds, they reminded that “in the southern Appalachians, a healthy rattlesnake population may be as high as 150 individuals, however here in Massachusetts, our populations are generally much smaller.”
Many locals, however, are not eagerly embracing the plan just yet. Peter Mallett, president of the Millers River Fishermen’s Association, was asked by the Boston Globe, “What could go wrong?” He replied: “Well, they swim.”
MassWildlife countered with this explanation: “While rattlesnakes are perfectly good swimmers, their survival depends on access to unusually deep hibernation sites, usually in a rock talus or boulder field below a ledge, or a deep fissure in bedrock. These special habitats are scarce on our landscape. Any snake that leaves the island whether by water or over the causeway will not be able to find a suitable hibernation site and if unable to return will die over the winter.”
The concerns are not just about swimming rattlesnakes, though. In a letter to the editor of the Globe, Brookline resident Ann Carol Grossman wrote:
Clearly the state Department of Fisheries and Wildlife learned nothing from the debacle resulting from the reintroduction of wild turkeys to the western part of the state. The birds are now the scourge of cities and suburbs all over metro Boston. I assume this was an unintended consequence, so I wonder what will be the unintended consequences of this new adventure involving breeding timber rattlesnakes. Maybe the turkeys and the rattlers will fight each other for the territory in our backyards.
Given the heated opinions on both sides of the argument, Tuesday’s meeting is bound to stir up emotions. In the meantime, the future of the region’s timber rattlesnake population hangs in the balance.