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

frog A frog is any member of a diverse and largely semiaquatic group of short-bodied, tailless amphibian vertebrates composing the order (biology), order Anura (coming from the Ancient Greek , literally 'without tail'). Frog species with rough ski ...

s from Europe that existed from the middle

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

to the middle

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

( 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 Pipoidea are a clade of frogs, that contains the most recent common ancestor of living Pipidae and Rhinophrynidae as well as all its descendants. It is broadly equivalent to Xenoanura. Description The synapomorphies that define Pipoidea are ...

, related to the South American-African family

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

, which includes the

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

and

Surinam toad The common Surinam toad, the Suriname toad, or star-fingered toad (''Pipa pipa''), is a fully-aquatic species of frog, in the family Pipidae, with a widespread range across much of tropical South America and the island of Trinidad. The females o ...

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 sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...

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 Films * Rana (2012 film), an Indian Kannada-language action drama * Rana, a 1998 Telugu-language action film directed by A. Kodandarami Reddy * R ...

diluviana'' from remains found in uppermost

Oligocene The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...

strata near

Bonn Bonn () is a federal city in the German state of North Rhine-Westphalia, located on the banks of the Rhine. With a population exceeding 300,000, it lies about south-southeast of Cologne, in the southernmost part of the Rhine-Ruhr region. This ...

in Germany. It was later recognised as distinct and placed in the new separate genus ''Palaeobatrachus'' by Tschudi in 1839. The Eocene genus '' Albionbatrachus'' 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 ( ; ; ) is the westernmost and largest historical region of the Czech Republic. In a narrow, geographic sense, it roughly encompasses the territories of present-day Czechia that fall within the Elbe River's drainage basin, but historic ...

, in Geiseltal (west

Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

) 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 Organ (biology), organs of the respiratory system in many animals, including humans. In mammals and most other tetrapods, two lungs are located near the Vertebral column, backbone on either side of the heart. Their ...

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 (derived from Latin ''lignum'' meaning 'wood'), often referred to as brown coal, is a soft, brown, Combustion, combustible sedimentary rock formed from naturally compressed peat. It has a carbon content around 25–35% and is considered ...

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

crustacean Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthrop ...

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 (geology), epoch in the geologic time scale that extends from 5.33 to 2.58Netherlands , Terminology of the Low Countries, informally Holland, is a country in Northwestern Europe, with Caribbean Netherlands, overseas territories in the Caribbean. It is the largest of the four constituent countries of the Kingdom of the Nether ...

, 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 country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

until the mid Pleistocene.

Description

Taxonomy

Habitat and paleoecology

References

Further reading