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Gosner stage is a generalized system of describing stages of embryonal and larval development in anurans (frogs and toads). The Gosner system includes 46 numbered stages, from fertilized embryo (stage 1) to the completion of metamorphosis (stage 46). It was introduced by Kenneth Gosner in 1960. [2]
The oldest fossil "proto-frog" Triadobatrachus is known from the Early Triassic of Madagascar (250 million years ago), but molecular clock dating suggests their split from other amphibians 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 ...
The archaeobatrachians are the most primitive of frogs. These frogs have morphological characteristics which are found mostly in extinct frogs, and are absent in most of the modern frog species. Most of these characteristics are not common between all the families of Archaeobatrachia, or are not absent from all the modern species of frogs.
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 plant matter. Frog skin has a rich microbiome which is important to their health. Frogs ...
Several of the genera within the Leptodactylidae lay their eggs in foam nests. These can be in crevices, on the surface of water, or on forest floors. These foam nests are some of the most varied among frogs. When eggs hatch in nests on the forest floor, the tadpoles remain within the nest, without eating, until metamorphosis.
Frogs are a diverse and largely carnivorous group of short-bodied, tailless amphibians composing the order Anura (Ancient Greek an-, without + oura, tail). 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.
Tree frogs typically have well-developed discs at the finger and toe tips, they rely on several attachment mechanisms that vary with circumstances, tree frogs require static and dynamic, adhesive and frictional, reversible and repeatable force generation; the fingers and toes themselves, as well as the limbs, tend to be rather small, resulting ...
The Batrachia / b ə ˈ t r eɪ k i ə / are a clade of amphibians that includes frogs and salamanders, but not caecilians nor the extinct allocaudates. [1] The name Batrachia was first used by French zoologist Pierre André Latreille in 1800 to refer to frogs, but has more recently been defined in a phylogenetic sense as a node-based taxon that includes the last common ancestor of frogs and ...