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... Science Frontiers ONLINE No. 76: Jul-Aug 1991 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Eight Leatherback Mysteries Our subject here is the leatherback turtle. Weighing up to 1600 pounds, it is the largest of the sea turtles. It is also the fastest turtle, hitting 9 miles per hour at times. But weight and speed are not necessarily mysterious; here are some characteristics that are: The leatherback is the only turtle without a rigid shell. Why? Perhaps it needs a flexible shell for its very deep dives. What looks like a shell is its thick, leathery carapace -- a strange streamlined structure with five to seven odd "keels" running lengthwise. These turtles are warm-blooded , and able to maintain their temperatures as much as 10 F above the ambient water, just as the dinosaurs apparently could. The bones of the leatherback are more like those of the marine mammals (dolphins and whales) than the reptiles. "No one seems to understand the evolutionary implications of this." Leatherbacks dive as deep as 3000 feet which is strange because they seem to subside almost exclusively on jellyfish, most of which are surface feeders. Like all turtles, leatherbacks can stay submerged for up to 48 hours. Just how they do this is unexplained. Their brains are miniscule. A 60-pound turtle possessed a brain weighing only 4 grams -- a rat's weighs 8! Leatherbacks' intestines contain waxy balls, recalling the ambergris found in the intestines of sperm whales. The stomachs of ...
Terms matched: 1 - Score: 222 - 15 May 2017 - URL: /sf076/sf076b07.htm
... Science Frontiers ONLINE No. 112: Jul-Aug 1997 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Sea turtles: from one end to the other Leatherback turtles are mysterious in several ways: flexible shell, warmbloodedness, etc. (See SF#76 for more.) Now, we add two more remarkable capabilities to their dossier. Precision navigation. The oily, flexible shells of leatherbacks have made it difficult for researchers to attach radio transmitters to the animals. Their very deep dives (over 1,000 meters) are also inimical to human instrumentation. But S.J . Morreale's group at Cornell have succeeded in attaching pressure-resistant transmitters to the shells on short tethers. This team was able to track female leatherbacks as they left their nesting beach in Costa Rica and headed southward, past the Galapagos, out into the open South Pacific. Surprisingly, all the leatherbacks plied a very narrow corridor each year of the experiment (1992-1995). In fact, the paths were almost for at least 2,700 kilometers southwest of the Galapagos. Highprecision navigation equipment is required here. Among the leatherbacks' "instruments" are probably sensors that detect the angle of the geomagnetic field, the length of daylight, and the identities of the oceanic currents encountered. There are probably other sensors and, of course, a brain to process all the signals; but virtually nothing is known about them. (Morreale, Stephen J., et al; "Migration Corridor for Sea Turtles," Nature, ...
Terms matched: 1 - Score: 70 - 15 May 2017 - URL: /sf112/sf112p08.htm
... Science Frontiers ONLINE No. 52: Jul-Aug 1987 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects New Vertebrate Depth Record S. Eckert, of the University of Georgia, has reported that a leatherback turtle fitted with a recording device dove to 1200 meters. This exceeds the previous record for air-breathing vertebrates (sperm whales). Leatherbacks also hold other records, being the largest of living turtles (over 600 kilograms) and the most widely distributed reptile in the world. They are also capable of maintaining their body temperatures sub stantially above the ambient water temperature, although no one has as yet claimed that they are warm-blooded. (Mrosovsky, N.; "Leatherback Turtle Off Scale," Nature, 327:286, 1987.) From Science Frontiers #52, JUL-AUG 1987 . 1987-2000 William R. Corliss ...
Terms matched: 1 - Score: 42 - 15 May 2017 - URL: /sf052/sf052b09.htm
... Science Frontiers ONLINE No. 76: Jul-Aug 1991 Other pages Home Page Science Frontiers Online All Issues Last Issue Next Issue Sourcebook Project Sourcebook Subjects Contents Archaeology An ancient egyptian ship in australia? THE MEXICAN SELLOS: POSSIBLE EVIDENCE FOR EARLY EUROPEAN CONTACTS The orogrande, nm, site Astronomy Catastrophic flooding on mars? Will earth's rings return? Biology Ants as "excitable subunits" Eight leatherback mysteries FLYING, PARACHUTING, AND FALLING FROGS Geology Baby oil UNDERGROUND CURRENT ELECTRIFIES AUSTRALIA Geophysics Atlantic's waves getting bigger Subterranean "circles" Psychology PSI EFFECTS IN THE SACRIFICE OF MARINE ALGAE Physics COLD FUSION: NEW EXPERIMENTS AND THEORIES NEW INSIGHTS AS TO THE STRUCTURE OF MATTER ...
Terms matched: 1 - Score: 15 - 15 May 2017 - URL: /sf076/index.htm
... Caecelian Origin Fish-Reptile Transition Fossils Crocodile Origin (Chemistry Contradicts Fossils) Ichthyosaur-Fish Convergence Dinosaurs with Bird-Like Bones Dinosaur Species Separated by Oceans Evolution of Flight Evolutionary Stasis Fish-Amphibian Transition Fossils Filter-Feeding Dinosaurs Sudden Appearances in the Fossil Record Orthogenesis Preadaptation in Reptiles Many Examples of Convergent Evolution Frog Origin Perplexing Ruminating Dinosaurs Unknown Purpose of Back Fans on Dinosaurs Origin of Fins on Marine Reptiles Evolutionary Stasis Vertical Flexure in Marine Reptiles Dinosaurs with Trunks Dinosaurs with Whale-Like Nostrils Web-Footed Dinosaurs BRF BODILY FUNTCIONS Parthenogenesis, Virgin Birth [BRA All-Female Species] Advantages of Female Promiscuity Survival of Freezing Tadpoleless-Frog Species Frog-Brooding and Tadpole Care Incubating Pythons Limb Regeneration Nursing of Young (Caecilians] How Are Enormous Prey Digested? Live-Bearing Lizards Warm-Blooded Leatherbacks Reptiles Never Stop Growing Giant Tadpoles That Become Tiny Frogs! Metamorphosis Enigmas Newt-Eye Regeneration Frogs without Tadpole Stage Live Birth in Frogs Infertile Eggs Laid for Food BRG GENETICS Green Turtle Populations Have Very Small Genetic Differences Homeobox-Gene Control of Body Plans Strong Convergence in Island Lizards [BRD] Chromosome-Number Effect upon Amphibian Development Frog Genes Jump between Species "Cryptic Species": Look Alike But Genetically Different Marked DNA Differences within Same Species BRI INTERNAL SYSTEMS AND STRUCTURES Low Antibody Diversity in Reptiles and Amphibians Magnetite Concentrations BRO ORGANS Lungs Used for Hearing Independent Eye Motion Lungless Salamanders Amphibian Lateral Lines Reptile Third Eyes [BRA] Eyes with Mirror Optics Rectal and Throat Gills in Turtles Blind Amphibians Snake Eyes Focus Like Fish Eyes (Except in the Long Nosed Trre Snake!] Snakes with Right Lung ...
Terms matched: 1 - Score: 5 - 15 May 2017 - URL: /cat-biol.htm
