''Livoniana'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

prehistoric Prehistory, also called pre-literary history, is the period of human history between the first known use of stone tools by hominins million years ago and the beginning of recorded history with the invention of writing systems. The use o ...

tetrapodomorphs Tetrapodomorpha (also known as Choanata) is a clade of vertebrates consisting of tetrapods (four-limbed vertebrates) and their closest sarcopterygian relatives that are more closely related to living tetrapods than to living lungfish. Advanced for ...

which lived during the

Devonian The Devonian ( ) is a period (geology), geologic period and system (stratigraphy), system of the Paleozoic era (geology), era during the Phanerozoic eon (geology), eon, spanning 60.3 million years from the end of the preceding Silurian per ...

period Period may refer to: Common uses * Period (punctuation) * Era, a length or span of time *Menstruation, commonly referred to as a "period" Arts, entertainment, and media * Period (music), a concept in musical composition * Periodic sentence (o ...

(

Givetian The Givetian is one of two faunal stages in the Middle Devonian Period. It lasted from million years ago to million years ago. It was preceded by the Eifelian Stage and followed by the Frasnian Stage. It is named after the town of Givet in ...

Frasnian The Frasnian is one of two faunal stages in the Late Devonian Period. It lasted from million years ago to million years ago. It was preceded by the Givetian Stage and followed by the Famennian Stage. Major reef-building was under way during ...

stages Stage, stages, or staging may refer to: Arts and media Acting * Stage (theatre), a space for the performance of theatrical productions * Theatre, a branch of the performing arts, often referred to as "the stage" * ''The Stage'', a weekly Brit ...

, about 374 - 391

million years ago Million years ago, abbreviated as Mya, Myr (megayear) or Ma (megaannum), is a unit of time equal to (i.e. years), or approximately 31.6 teraseconds. Usage Myr is in common use in fields such as Earth science and cosmology. Myr is also used w ...

). This species is a transitional form between fish and the earliest

tetrapod A tetrapod (; from Ancient Greek :wiktionary:τετρα-#Ancient Greek, τετρα- ''(tetra-)'' 'four' and :wiktionary:πούς#Ancient Greek, πούς ''(poús)'' 'foot') is any four-Limb (anatomy), limbed vertebrate animal of the clade Tetr ...

s, like ''

Tiktaalik ''Tiktaalik'' (; ) is a monospecific genus of extinct sarcopterygian (lobe-finned fish) from the Late Devonian Period, about 375 Mya (million years ago), having many features akin to those of tetrapods (four-legged animals). ''Tiktaalik'' is est ...

'', ''

Ichthyostega ''Ichthyostega'', from Ancient Greek ἰχθύς (''ikthús''), meaning "fish", and στέγη (''stégē''), meaning "roof", is an Extinction, extinct genus of limbed tetrapodomorpha, tetrapodomorphs from the Devonian, Late Devonian of what is ...

'' and ''

Acanthostega ''Acanthostega'', from Ancient Greek ἄκανθα (''ákantha''), meaning "spine", and στέγη (''stégē''), meaning "roof", is an extinct genus of stem tetrapoda, stem-tetrapod, among the first vertebrates, vertebrate animals to have recogn ...

''. Before ''Livoniana'' there was ''

Elginerpeton ''Elginerpeton'' is a genus of stegocephalian ( stem-tetrapod), the fossils of which were recovered from Scat Craig, Morayshire in the UK, from rocks dating to the late Devonian Period (Late Frasnian stage, 375 million years ago). The type spe ...

'' and ''

Obruchevichthys ''Obruchevichthys'' is an extinct genus of stem-tetrapod from Latvia during the Late Devonian. When the jawbone, the only known fossil of this creature, was uncovered in Latvia, it was mistaken as a lobe-fin fish. However, when it was analyze ...

''. Four legs developed in water, not on land, to better escape waterliving predatory creatures like ''

Hyneria ''Hyneria'' is a genus of large prehistoric predatory lobe-finned fish which lived in fresh water during the Famennian stage of the Devonian period. Etymology The genus name ''Hyneria'' is a reference to the village of Hyner, Pennsylvania, n ...

''. There were very lush forests, and particularly swamps, where four limbs became very useful to avoid predators.

References

External links

''Livoniana multidentata''
at Devonian Times Elpistostegalia Prehistoric lobe-finned fish genera Middle Devonian sarcopterygians Late Devonian sarcopterygians Devonian sarcopterygians of Europe Transitional fossils {{paleo-tetrapodomorph-stub