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.
'Cold-blooded' pythons make for caring moms
on March 14, 2018 at 2:20 pm
The female Southern African python is the first ever egg-laying snake species shown to care for their babies. This comes at great cost to themselves, as they never eat during the breeding period -- with many snakes starving -- and turn their color to black in order to attract more sun while basking to raise their body temperature. […]
Male loggerhead turtles also go back to their...
on March 14, 2018 at 1:27 pm
Most male loggerhead turtles go back to the nesting beaches to breed –- a common behavior among female turtles --, according to a new study. […]
60-year-old paleontological mystery of a...
on March 14, 2018 at 1:23 pm
A new study has re-discovered fossil collections from a 19th century hermit that validate 'phantom' fossil footprints collected in the 1950s showing dicynodonts coexisting with dinosaurs. […]
Early warning system for deadly amphibian pathogen
on March 12, 2018 at 2:40 pm
Environmental DNA is a new technology that detects telltale bits of genetic material that living creatures shed into their environment. Scientists demonstrate for the first time that it can be used to detect the presence of a deadly pathogen before it wipes out populations of amphibians. […]
Life in the fast flow: Tadpoles of new species...
on March 12, 2018 at 12:51 pm
The young of two new species and a genus of frog found to inhabit Sumatra's rainforests have developed a unique ability to latch onto rocks in the fast-flowing rivers, using bellies crafted by evolution into 'suction cups'. Herpetologists use their remarkable discovery to highlight the unique biodiversity of the island, which is under imminent threat due to rampant habitat modification and deforestation. […]