Reptiles
laelaps | March 23, 2009
A Cuban crocodile (Crocodylus rhombifer), photographed at the National Zoo.
edyong | February 4, 2009
This is sure to be one of the most amazing scientific images of the year. You're looking at vertebrae from two species of snake. The smaller model on the left belongs to the anaconda, a giant serpent that can grow to 7 metres in length and weigh as much as 45kg. It's arguably the largest snake alive, so just think about how big the owner of the fossilised vertebra on the right would have been! There's a good reason why this new discovery - the largest snake that ever slithered - has been named Titanoboa.
Titanoboa cerrejonesis is new to science and was discovered by a team of North…
grrlscientist | January 29, 2009tags: Loggerhead Sea Turtle, Caretta caretta, Joel Sartore, National Geographic, image of the day
Loggerhead Sea Turtle (Caretta caretta)
90,000 remaining.
Image: Joel Sartore/National Geographic [larger view].
The photographer writes:
Biologists tally nests, not individuals. Some 47,000 to 90,000 nests were counted each year on the Atlantic Coast over the past decade.
Joel Sartore has shared some of his work on this blog before, so I am thrilled to tell you that National Geographic also appreciates his exemplary work. You can view more endangered animals of the United States that were…
grrlscientist | January 23, 2009tags: Gopher Tortoise, Gopherus polyphemus, Joel Sartore, National Geographic, image of the day
Gopher Tortoise (Gopherus polyphemus).
Image: Joel Sartore/National Geographic [larger view].
The photographer writes;
Gopher tortoises in the southeastern U.S. often end up as roadkill. Invasive fire ants and armadillos also prey on their eggs and young, while urban expansion, land conversion for pine plantations, and fire mismanagement degrade tortoise habitat, pushing these reptiles closer to the edge.
Joel Sartore has shared some of his work on this blog before, so I am thrilled to tell you…
edyong | January 7, 2009
For humans and other mammals, sex is neatly determined by the X and Y chromosomes. If you have a Y you are male, and without it you are female. Reptiles however, use a variety of strategies, and the mammalian X/Y system is just one of them.
In some species, the female is the one with different chromosomes, in this case Z and W, and the male has two Zs. And some reptiles ignore sex chromosomes altogether. For them, an individual's sex is determined by the temperature that their eggs were incubated at.
Scientists had long believed that these strategies were mutually exclusive with each…
edyong | January 5, 2009
One hundred and seventy-four years ago, Charles Darwin first set foot on the Galapagos Islands aboard the Beagle. Since then, the islands and the unique species they house have been a source of inspiration for many an evolutionary biologist. Even so, it is gratifying to see that even now, on the bicentennial of Darwin's birth, the Galapagos have not yet finished yielding their secrets.
During Darwin's five-week stint on the Galapagos, he observed two types of iguana. One was a marine version that, uniquely for lizards, swam and fed in the ocean, and the other was a cactus-eating landlubber…
edyong | December 20, 2008
Miners used to take canaries into unfamiliar shafts to act as early warning systems for the presence of poisons. Today, climate scientists have their own canaries - amphibians. Amphibians - the frogs, toads and salamanders - are particularly susceptible to environmental changes because of their fondness for water, and their porous absorbent skins. They are usually the first to feel the impact of environmental changes.
And feel it they have. They are one of the most threatened groups of animals and one in three species currently faces extinction. The beautiful golden toad (right) was one of…
grrlscientist | December 10, 2008tags: green sea turtles, Hawaii, landscape, nature, image of the day
Egg-laying Green Sea Turtles
Pacific green (black) sea turtle Chelonia mydas, Maui, Hawai'i.
Image: John del Rio [larger view].
edyong | November 26, 2008 Clad in hard, armoured shells, turtles have a unique body plan unlike that of any other animal. Their shells have clearly served them well and the basic structure has gone largely unchanged since the time of the dinosaurs. But this unchanging nature poses a problem for anyone trying to understand how they evolved and until now, fossil turtles haven't provided any clues. All of them, just like their living descendants, have fully formed two-part shells.
But three stunning new fossils are very different. They belong to the oldest turtle ever discovered, which lived about 220 million years ago…
laelaps | November 19, 2008
A red-eared slider (Trachemys scripta elegans), photographed at the Bronx Zoo.
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laelaps | November 15, 2008
A lace monitor (Varanus varius), photographed at the Bronx Zoo.
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edyong | November 12, 2008
Hair, or fur, is one of the hallmarks of mammals, the group of animals to which we belong. It is an evolutionary innovation that provides us with protection and helps us to maintain our constant body temperature And while hair is a uniquely mammalian feature, its genetic building blocks are anything but. A new study has found that genes responsible for building the locks on your head have counterparts that construct the claws of lizards.
Hair is made of proteins called keratins, which interact with each other to form long, hard filaments. Keratins are widespread in the animal world but…
laelaps | November 11, 2008
A false gharial (Tomistoma schlegelii), photographed at the Bronx Zoo.
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grrlscientist | November 8, 2008tags: Lepidodactylus buleli, new species discovered, Vanuatu gecko, reptiles, Ivan Ineich, Natural History Museum Paris France
French scientist, Ivan Ineich, displays a never-before-seen species of gecko at France's Natural History Museum in Paris. This gecko, formally described with the Latin name, Lepidodactylus buleli, was born in Paris from an egg that was removed from the rainforest canopy on the west coast of Espiritu Santo, one of the larger islands of the Vanuatu Archipelago, east of Australia in the South Pacific Ocean.
IMAGE: Francois Mori (AP Photo) [larger view].
According…
laelaps | October 30, 2008
A red-eared slider (Trachemys scripta elegans), photographed at the Bronx Zoo.
edyong | October 13, 2008
Many animals use poisonous secretions to protect themselves from predators. But poisons are complex chemicals and can take a lot of energy to make. Why invest in them, when you can steal someone else's?
Poison thieves are well-known in the animal kingdom. Many species of brightly coloured poison arrow frogs acquire their poisons from beetles, while some sea slugs make a living by hunting for jellyfish, transporting their stinging cells into their own limbs. Now, another species joins this guild of thieves - the tiger keelback snake, Rhabdophis tigrinis (image right, by Deborah…
edyong | October 3, 2008
According to Christian lore, Mary gave birth to baby Jesus without ever having had sex with Joseph. A biologist might describe this as 'parthenogenesis', the Greek version of the more familiar phrase 'virgin birth'('parthenos' means virgin, and 'genesis' means birth). The New Testament aside, shunning fertilisation and giving birth to young through parthenogenesis is rare among higher animals, occurring in only one in every thousand species. Nonetheless, two Christmases ago, eight virgin births took place in the English town of Chester. The mother's name was Flora and she was a komodo…
laelaps | October 2, 2008
A Chinese alligator (Alligator sinensis), photographed at the Philadelphia zoo.