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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.
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).
The frog family Dicroglossidae [1] [2] occurs in tropical and subtropical regions of Asia and Africa, with most genera and species being found in Asia. The common name of the family is fork-tongued frogs. [1] The Dicroglossidae were previously considered to be a subfamily in the family Ranidae, but their position as a family is now well ...
Many frogs in this genus breed in early spring, although subtropical and tropical species may breed throughout the year. Males of most of the species are known to call, but a few species are thought to be voiceless. Females lay eggs in rafts or large, globular clusters, and can produce up to 20,000 at one time.
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 ...
[16] [17] Molecular studies of extant amphibians based on multiple-locus data favor one or the other of the monophyletic alternatives and indicate a Late Carboniferous date for the divergence of the lineage leading to caecilians from the one leading to frogs and salamanders, and an early Permian date for the separation of the frog and ...
European treefrog (Hyla arborea). A tree frog (or treefrog) is any species of frog that spends a major portion of its lifespan in trees, known as an arboreal state. [1] Several lineages of frogs among the Neobatrachia suborder have given rise to treefrogs, although they are not closely related to each other.