''Palaeobatrachus'' (meaning "ancient frog" in Greek) is an extinct genus of

frog A frog is any member of a diverse and largely Carnivore, carnivorous group of short-bodied, tailless amphibians composing the order (biology), order Anura (ανοὐρά, literally ''without tail'' in Ancient Greek). The oldest fossil "proto-f ...

s from Europe that existed from the middle

Eocene The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...

to the middle

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...

( Ionian Stage) (621-568,000 years ago), spanning almost 50 million years. They were obligately aquatic, and would have not spent much time on dry land. They are one of two genera and by far the largest genus in the family

Palaeobatrachidae Palaeobatrachidae is an extinct family of frogs known from the Late Cretaceous to the Pleistocene primarily of Europe. They were highly adapted to aquatic life, like other members of the Pipimorpha. The oldest undoubted records of the family are ...

, which are considered to be members of

Pipimorpha Pipimorpha is an unranked clade containing all frogs which are more closely related to living Pipidae species than to living ''Rhinophrynus'' species. Members of this group are highly adapted to aquatic life. The oldest pipimorphs are '' Neusibat ...

, related to the South American-African family

Pipidae The Pipidae are a family of primitive, tongueless frogs. The 41 species in the family Pipidae are found in tropical South America (genus ''Pipa'') and sub-Saharan Africa (the three other genera). Description Pipid frogs are highly aquatic and ...

, which includes the

African clawed frog The African clawed frog (''Xenopus laevis'', also known as the xenopus, African clawed toad, African claw-toed frog or the ''platanna'') is a species of African aquatic frog of the family Pipidae. Its name is derived from the three short claws ...

and Surinam toad.

Description

''Palaeobatrachus'' had a relatively broad skull the shape of a Gothic arch. Its body was relatively large, ranging from in length, and the female was usually larger than the male (

sexual dimorphism Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...

Taxonomy

''Palaeobatrachus'' was the first fossil frog to be described, with the first species being ''P. diluvianus'' named by Goldfuss in 1831, originally as ''

Rana Rana may refer to: Astronomy * Rana (crater), a crater on Mars * Delta Eridani or Rana, a star People, groups and titles * Rana (name), a given name and surname (including a list of people and characters with the name) * Rana (title), a histori ...

diluviana'' from remains found in uppermost

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the ...

strata near

Bonn The federal city of Bonn ( lat, Bonna) is a city on the banks of the Rhine in the German state of North Rhine-Westphalia, with a population of over 300,000. About south-southeast of Cologne, Bonn is in the southernmost part of the Rhine-Ruhr r ...

in Germany. It was later recognised as distinct and placed in the new separate genus ''Palaeobatrachus'' by Tschudi in 1839. The Eocene genus ''

Albionbatrachus ''Albionbatrachus'' is an extinct genus of prehistoric frogs from England and Romania. Two species are recognized: While previously synonymised with ''Palaeobatrachus'', it is now considered a distinct palaeobatrachid genus based on characters o ...

'' was considered a synonym of ''Palaeobatrachus'' by Wuttke et al. (2012), but Roček et al. (2015) retained it as a separate taxon. The nominal species ''Palaeobatrachus occidentalis'' was described from material found in the Late Cretaceous-Early Paleocene of western North America, but Roček (2013) questioned its generic attribution.

Habitat and paleoecology

Its skeletal remains are plentiful in freshwater sediments in western

Bohemia Bohemia ( ; cs, Čechy ; ; hsb, Čěska; szl, Czechy) is the westernmost and largest historical region of the Czech Republic. Bohemia can also refer to a wider area consisting of the historical Lands of the Bohemian Crown ruled by the Bohem ...

, in Geiseltal (west

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

) and in east Germany. They are sometimes preserved very well indeed, with impressions of internal organs, muscles, nerves, blood vessels and epidermis, and with traces of coloring. Tadpoles and eggs have also been found. These frogs lived permanently in water. Their bag-shaped

lung The lungs are the primary organs of the respiratory system in humans and most other animals, including some snails and a small number of fish. In mammals and most other vertebrates, two lungs are located near the backbone on either side of t ...

s, on the dorsal side of their body, enabled them to remain submerged for long periods. They inhabited through-drainage basins or swamps where

brown coal Lignite, often referred to as brown coal, is a soft, brown, combustible, sedimentary rock formed from naturally compressed peat. It has a carbon content around 25–35%, and is considered the lowest rank of coal due to its relatively low heat ...

deposits were formed. Like the African clawed toad, they probably lived on small

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...

s, insect larvae and small fish and themselves provided sustenance for many other animals. The climatic change at the beginning of the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58Netherlands ) , anthem = ( en, "William of Nassau") , image_map = , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of the Netherlands , established_title = Before independence , established_date = Spanish Netherl ...

, acting as a refugium for ''Palaeobatrachus'', made it possible for one species (''P. eurydices'') to survive in western europe as recently as the early Pleistocene. In addition a species persisted in southern

Russia Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...

until the mid Pleistocene.

Description

Taxonomy

Habitat and paleoecology

References

Further reading