Turtles



Turtles, Tortoises, and Terrapins are reptiles of the Order Testudines (all living turtles belong to the crown group Chelonia), most of whose body is shielded by a special bony or cartilagenous shell developed from their ribs. The Order Testudines includes both extant (living) and extinct species, the earliest known turtles being from around 215 million years ago, making turtles one of the oldest reptile groups, and a much more ancient group than lizards and snakes. About 300 species are alive today; some are highly endangered.




Paleontology



Turtle Fossils




Mythology


Turtle Island is the name of North America, according to some indigenous groups. The Lenape story of the "Great Turtle" was first recorded between 1678 and 1680 by Jasper Danckaerts. The story is shared by other Northeastern Woodlands tribes, notably the Iroquois. The term originates mainly from oral tradition, in the tale of the westward travel of the Anishinabe tribe on the land known as Turtle Island, as recorded also in the birch bark scrolls.

According to Iroquois oral history, Sky Woman fell down to the earth when it was covered with water. Various animals tried to swim to the bottom of the ocean to bring back dirt to create land. Muskrat succeeded in gathering dirt, which was placed on the back of a turtle, which grew into the land known today as North America. In the Seneca language, the mythical turtle is called Hah-nu-nah, while the name for an everyday turtle is ha-no-wa.

The name Turtle Island is used today by many Native tribes, Native rights activists, and environmental activists, especially since the 1970s when the term came into wider usage. In a later essay, published in At Home on the Earth, Gary Snyder claimed this title as a term referring to North America that synthesizes both indigenous and colonizer cultures by translating the indigenous name into the colonizer's languages (the Spanish "Isla Tortuga" being proposed as a name as well). Snyder argues that understanding North America under the name of Turtle Island will help shift conceptions of the continent.




Maya



Heathstone constellation, positioned on the back of the turtle, or the constellation Orion, seen on Madrid Codex page 71a (after Codice Tro-Cortesianus (Codex Madrid). Akademische Druck-und Verlagsanstalt, Graz, 1967). It consists of the stars Alnitak (the lowest star in Orion's Belt), Saiph, and Rigel.




In the News ...





8-Year-Old's Fossil Discovery Explains Why Turtles Have Shells   Live Science - July 18, 2016
The proto-turtle Eunotosaurus burrows into the banks of a dried up pond to survive in the harsh, arid South African environment about 260 million years ago. In the background, a herd of Bradysaurus, a type of reptile, crowds around some muddy water. The turtle's shell may serve as a protective shield nowadays, but ancient turtles actually developed shells for an entirely different reason, a new study finds. Researchers looked at the remains of 47 ancient proto-turtles (Eunotosaurus africanus), ancient reptiles that sported partial shells. These animals had broadened ribs that likely helped them burrow underground, rather than serving as protective armor, the researchers said.




Researchers discover real reason why turtles have shells   PhysOrg - July 15, 2016
The earliest beginnings of the turtle shell was not for protection but rather for digging underground to escape the harsh South African environment where these early proto turtles lived.




  Famous Giant Turtle Dies - Only Three Left on Earth   National Geographic - February 2, 2016

The death of Cu Rua, long revered in Vietnam, brings the critically endangered Yangtze giant softshell turtle one step closer to extinction.




New Giant Tortoise Species Found on Galapagos Islands   National Geographic - October 21, 2015

The reptiles evaded detection as a distinct species for over a hundred years.


New Species of Giant Tortoise Found in the Galapagos   Live Science - October 21, 2015
Paging Charles Darwin: The island of Santa Cruz within the Galapagos has not one but two distinct species of giant tortoise, a new genetic study finds. For years, researchers thought that the giant tortoises living on the western and eastern sides of Santa Cruz belonged to the same species. But the tortoises look slightly different, and so recently, scientists ran genetic tests on about 100 tortoises from both groups. The tests were definitive: The two tortoise populations, which live only about 6 miles (10 kilometers) apart on the opposite sides of the island, are actually extremely distant relatives.




'Lost' sea turtles don't go with the flow   BBC - April 10, 2015

A tracking study has shown that young sea turtles make a concerted effort to swim in particular directions, instead of drifting with ocean currents. Baby turtles disappear at sea for up to a decade and it was once assumed that they spent these "lost years" drifting.




Turtles and dinosaurs: Scientists solve reptile mysteries with landmark study on the evolution of turtles   Science Daily - November 24, 2014

A team of scientists has reconstructed a detailed 'tree of life' for turtles. Next generation sequencing technologies have generated unprecedented amounts of genetic information for a thrilling new look at turtles' evolutionary history. Scientists place turtles in the newly named group 'Archelosauria' with their closest relatives: birds, crocodiles, and dinosaurs.




Meet Jonathan, St Helena's 182-year-old giant tortoise   BBC - March 13, 2014

Jonathan is a rare Seychelles Giant. His lawn-fellows hail from the Aldabra Atoll in the Indian Ocean. Aldabra Giants number about 100,000, but only one small breeding population of Seychelles tortoises exists.During the 17th Century ships could contain hundreds of easily-stacked tortoises, like a fast-food takeaway. In the Galapagos islands alone around 200,000 tortoises are thought to have been killed and eaten at this time. How did Jonathan avoid this fate?




The Origin of the Turtle Shell: Mystery Solved   Science Daily - July 9, 2013

By observing the development of different animal species and confirming their results with fossil analysis and genomic data, researchers from the RIKEN Center for Developmental Biology show that the shell on the turtle's back derives only from its ancestors' ribcage and not from a combination of internal and external bone structures as is often thought. Their study is published today in the journal Nature Communications. The skeleton of vertebrates has evolved throughout history from two different structures, called the endo- and exoskeleton. In the human skeleton, the backbone and bones of the limbs evolved from the endoskeleton, whereas most of the skull elements derive from the exoskeleton. Fish scales and the alligator's bony skin nodules are other examples of exoskeletons.




How the turtle got its unique hard shell   BBC - May 31, 2013

How the turtle shell evolved has puzzled scientists for years, but new research sheds light on how their hard shells were formed. Scientists say the ancient fossil skeleton of an extinct South African reptile has helped bridge a 30 to 55-million-year gap. This ancestor of the modern turtle, Eunotosaurus, is thought to be around 260 million years old. It had significant differences to a recently found fossil relative. Eunotosaurus was discovered over a century ago but new research in the journal Current Biology has only now analyzed its differences to other turtle fossils.




  Last Pinta giant tortoise Lonesome George dies   BBC - June 25, 2012

Staff at the Galapagos National Park in Ecuador say Lonesome George, a giant tortoise believed to be the last of its subspecies, has died. Scientists estimate he was about 100 years old. Park officials said they would carry out a post-mortem to determine the cause of his death.With no offspring and no known individuals from his subspecies left, Lonesome George became known as the rarest creature in the world. For decades, environmentalists unsuccessfully tried to get the Pinta Island tortoise to reproduce with females from a similar subspecies on the Galapagos Islands.




Leatherback turtles tracked on Atlantic 'danger' trips   BBC - January 5, 2011

Scientists have for the first time tracked leatherback turtles from the world's largest nesting site, in Gabon, as they traverse the South Atlantic. Data from tags on their backs show they swim thousands of kilometres each year. These journeys take them through areas where they are at high risk of being caught accidentally by fishing boats. The leatherback is the world's biggest turtle and listed as Critically Endangered, largely because of poaching for eggs and snaring in fishing gear.




Ancient Thick-shelled Turtle Discovered in Coal Mine   Live Science - April 10, 2010
A new fossil turtle species discovered in South America boasts quite a bulky shell - about as thick as your average high-school textbook. The shell, about 3.3 feet (1 meter) across and 1.4 inches (3.5 centimeters) thick, might have protected the turtle against attacks from large crocodile-like animals as well as the giant Titanoboa, the world's largest snake (about 45-feet long), which would have shared this turtle's neighborhood around 60 million years ago, the researchers say.




Turtles Have Shells Due to Embryo "Origami"   National Geographic - July 9, 2009
Turtles develop their upper shells thanks to a unique feat of "origami" with their muscles and bones that occurs while the reptiles are still in their eggs, a new study has found. In most other animals with backbones, the shoulder blade lies outside the ribs, but in turtles, the ribs grow over the shoulder blades and fuse to form the upper shell.




Albino Baby Turtle   National Geographic - June 26, 2009




Two-headed turtle goes on display in Pa. AP - September 27, 2007

Orristown, Pa. - A two-headed turtle captured by a turtle collector is a rare example of a conjoined-twin birth, its owner said. The turtle would have likely died in the wild because it swims awkwardly and would be an easy target for predators, according to Jay Jacoby, manager of Big Al's Aquarium Supercenter in East Norriton. The store bought the tiny turtle from the collector for an undisclosed price and will keep it on display, he said. The 2-month-old turtle, known as a red-eared slider, fits on a silver dollar. It has two heads sticking out from opposite ends of its shell, along with a pair of front feet on each side. But there is just one set of back feet and one tail. The turtle is seemingly healthy, and the species can live 15 to 20 years, Jacoby said. The turtle has not yet been named. The same exotic-turtle collector sold another Big Al's store a conjoined-twin turtle about 20 years ago, Jacoby said. The man lives in Florida, but he declined to identify him




Baby tortoise with two heads People's Daily - September 29, 2005

A woman holds a baby tortoise with two heads in Havana September 27, 2005. The tortoise was found some days ago on a river bank at the city forest. According to scientists of the local aquarium who inspected the animal, it seems to be perfectly healthy.





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