These are organized by a classification scheme developed exclusively for Cosma. More…
frog : DEFINITION — Webster
Frog is any member of a diverse and largely carnivorous group of short-bodied, tailless amphibians composing the order Anura. The oldest fossil “proto-frog” appeared in the early Triassic of Madagascar, but molecular clock dating suggests their origins may extend further back to the Permian, 265 million years ago. Frogs are widely distributed, ranging from the tropics to subarctic regions, but the greatest concentration of species diversity is in tropical rainforests. There are approximately 4,800 recorded species, accounting for over 85% of extant amphibian species. They are also one of the five most diverse vertebrate orders.
The body plan of an adult frog is generally characterized by a stout body, protruding eyes, cleft tongue, limbs folded underneath, and the absence of a tail in adults. Besides living in fresh water and on dry land, the adults of some species are adapted for living underground or in trees. The skin of the frog is glandular, with secretions ranging from distasteful to toxic. Warty species of frog tend to be called toads but the distinction between frogs and toads is based on informal naming conventions concentrating on the warts rather than taxonomy or evolutionary history; some toads are more closely related to frogs than to other toads. Frogs’ skins vary in color from well-camouflaged dappled brown, grey and green to vivid patterns of bright red or yellow and black to advertise toxicity and warn off predators.
Frogs typically lay their eggs in water. The eggs hatch into aquatic larvae called tadpoles that have tails and internal gills. They have highly specialized rasping mouth parts suitable for herbivorous, omnivorous or planktivorous diets. The life cycle is completed when they metamorphose into adults. A few species deposit eggs on land or bypass the tadpole stage. Adult frogs generally have a carnivorous diet consisting of small invertebrates, but omnivorous species exist and a few feed on fruit. Frogs are extremely efficient at converting what they eat into body mass.
They are an important food source for predators and part of the food web dynamics of many of the world’s ecosystems. The skin is semi-permeable, making them susceptible to dehydration, so they either live in moist places or have special adaptations to deal with dry habitats. Frogs produce a wide range of vocalizations, particularly in their breeding season, and exhibit many different kinds of complex behaviours to attract mates, to fend off predators and to generally survive. — Wikipedia
Frogs and Reptiles News -- ScienceDaily Snakes, lizards, alligators, frogs and toads. From habitat information to frogs in stem cell research, you will find all the reptile and amphibian news here.
Lizards of Oz take toll on turtle eggs
on December 14, 2017 at 3:08 pm
Goannas have overtaken foxes as the number one predator of the endangered loggerhead turtle at its second largest Queensland nesting beach. A new study has found that since feral red foxes were controlled in the 1980s, there has been an increase in the number goanna raids on loggerhead turtle nests at Wreck Rock beach, south of Agnes Waters. […]
Mapping the evolutionary history of a sugar gene
on December 14, 2017 at 3:01 am
The gene CMAH, that allows for the synthesis of a sugar called Neu5Gc, is missing from humans. This sugar is present in red meats, some fish and dairy products. When humans consume an animal with that gene, the body has an immune reaction to the foreign sugar, which can cause inflammation, arthritis, and cancer. Researchers have analyzed 322 animal genome sequences looking for animals with the presence of active CMAH genes. […]
Suburban ponds are a septic buffet
on December 12, 2017 at 5:54 pm
Human waste accounts for a high percentage of nutrients consumed by some animals and plants in suburban ponds, new research indicates. Researchers found that residential, suburban land use is altering the dynamics of the food chain, as well as where nutrients originate and how they move through pond ecosystems. […]
It's all in the ears: Inner ears of extinct sea...
on December 7, 2017 at 7:16 pm
A new study has revealed that an extinct group of marine reptiles called sauropterygians evolved similar inner ear proportions to those of some modern day aquatic reptiles and mammals. […]
Satellite tracking provides clues about South...
on December 6, 2017 at 7:16 pm
Biologists have been tracking the movements of sea turtle yearlings in the South Atlantic Ocean, and have come up with some surprising results. […]