Sanyanlichan
Encyclopedia
"Sanyanlichan" is the name given to a fossil that represents the earliest known "modern" frog
Frog
Frogs are amphibians in the order Anura , formerly referred to as Salientia . Most frogs are characterized by a short body, webbed digits , protruding eyes and the absence of a tail...

. The fossil dates to approximately 125 million years ago (Early Cretaceous
Early Cretaceous
The Early Cretaceous or the Lower Cretaceous , is the earlier or lower of the two major divisions of the Cretaceous...

), and was found in the fossil beds of Sihetun, in the western part of Liaoning
Liaoning
' is a province of the People's Republic of China, located in the northeast of the country. Its one-character abbreviation is "辽" , a name taken from the Liao River that flows through the province. "Níng" means "peace"...

 province, China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

. It possessed most "frog characteristics", being the earliest known example of these, but also had nine presacral vertebrae (one more than modern frogs). It may have been an ancestor of the Discoglossidae
Discoglossidae
Discoglossidae is a family of primitive frogs, with the common name Disc-Tongued Frogs. Most are endemic to Europe, but there are also three species in North-West Africa, and an extinct species formerly occurred in Israel....

 family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 of frogs, which includes the famous fire bellied toad.

Although "sanyanlichan" is the earliest known example of a fully modern frog, a Triassic
Triassic
The Triassic is a geologic period and system that extends from about 250 to 200 Mya . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events...

 genus, Triadobatrachus
Triadobatrachus
Triadobatrachus is an extinct genus of frog-like amphibian, including only one known species, Triadobatrachus massinoti. It is the oldest frog known to science, and an excellent example of a transitional fossil...

, represents the earliest known "frog". However, this genus still retained many salamander
Salamander
Salamander is a common name of approximately 500 species of amphibians. They are typically characterized by a superficially lizard-like appearance, with their slender bodies, short noses, and long tails. All known fossils and extinct species fall under the order Caudata, while sometimes the extant...

traits, thus is not a "fully modern frog".

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