Palaeobatrachidae are an extinct family of frogs whose earliest members are recorded from the
Middle Eocene (Geiseltal Messel Germany) almost 50 million years ago although there are
indications that they appeared as early as before the Cretaceous mass extinction event and
survived almost to our times. Their last survivors are recorded from the Middle Pleistocene
less than 0.5 million years ago such that they were contemporaries of Neanderthal man. Their
last fossil evidence is from the regions that were adjacent to the Pleistocene continental
glacier. Like today's pipid frogs (e.g. Xenopus) they were obligate water dwellers not able
to make long excursions onto dry land. Without exaggerating they literally died out frozen in
their ponds. Permanent life in water has a uniforming effect. This is why they all looked
similar to one another which is a source of difficulty for taxonomists. On the other hand one
cannot overlook features they have in common with pipids restricted to the southern
hemisphere. Palaeobatrachus and Xenopus are undoubtedly related but when and why ancestors of
Palaeobatrachus immigrated to the western part of northern Eurasia but not to its eastern part
and not to North America remains a puzzling question. Thus being acquainted with
Palaeobatrachus means to be invited on an excursion not only into comparative anatomy but also
into paleogeography and many other fields of palaeontology. Last but not least Palaeobatrachus
was the first fossil frog scientifically described as early as in 1831. Since that time many
excavation sites from which original material came have ceased to exist thus there is no
possibility that further material will be recovered. What is now deposited in scientific
collections is the unique and limited source of data for future comparative studies. This is
one of the main reasons why this rich illustrated review was published.
