Trematosauridae are a family of large marine

temnospondyl Temnospondyli (from Greek language, Greek τέμνειν, ''temnein'' 'to cut' and σπόνδυλος, ''spondylos'' 'vertebra') is a diverse order (biology), order of small to giant tetrapods—often considered Labyrinthodontia, primitive amphi ...

amphibians with many members. They first appeared during the

Induan The Induan is the first age of the Early Triassic epoch in the geologic timescale, or the lowest stage of the Lower Triassic series in chronostratigraphy. It spans the time between 251.902 Ma and Ma (million years ago). The Induan is sometimes ...

age Age or AGE may refer to: Time and its effects * Age, the amount of time someone or something has been alive or has existed ** East Asian age reckoning, an Asian system of marking age starting at 1 * Ageing or aging, the process of becoming older ...

of the

Early Triassic The Early Triassic is the first of three epochs of the Triassic Period of the geologic timescale. It spans the time between Ma and Ma (million years ago). Rocks from this epoch are collectively known as the Lower Triassic Series, which is a un ...

, and existed until around the

Carnian stage The Carnian (less commonly, Karnian) is the lowermost stage of the Upper Triassic Series (or earliest age of the Late Triassic Epoch). It lasted from 237 to 227 million years ago (Ma). The Carnian is preceded by the Ladinian and is followed by t ...

of the

Late Triassic The Late Triassic is the third and final epoch (geology), epoch of the Triassic geologic time scale, Period in the geologic time scale, spanning the time between annum, Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch ...

, although by then they were very rare. By the

Middle Triassic In the geologic timescale, the Middle Triassic is the second of three epochs of the Triassic period or the middle of three series in which the Triassic system is divided in chronostratigraphy. The Middle Triassic spans the time between Ma and ...

they had become widespread throughout

Laurasia Laurasia () was the more northern of two large landmasses that formed part of the Pangaea supercontinent from around ( Mya), the other being Gondwana. It separated from Gondwana (beginning in the late Triassic period) during the breakup of Pan ...

and

Gondwana Gondwana () was a large landmass, often referred to as a supercontinent, that formed during the late Neoproterozoic (about 550 million years ago) and began to break up during the Jurassic period (about 180 million years ago). The final stages ...

with fossils being found in Europe, Asia, Madagascar, and Australia. Trematosaurus1DB

They are one of the most derived families of the

Trematosauroidea Trematosauroidea are an important group of Triassic temnospondyl amphibians. They flourished briefly during the Early Triassic, occurring worldwide before declining at the start of the Middle Triassic, although the group continued until the Late ...

superfamily in that they are the only family that have fully marine lifestyles. Long, slender snouts that are characteristic of the trematosaurids, with some members having rostrums resembling those of modern-day

gavial The gharial (''Gavialis gangeticus''), also known as gavial or fish-eating crocodile, is a crocodilian in the family (biology), family Gavialidae and among the longest of all living crocodilians. Mature females are long, and males . Adult males ...

s. Traditionally, two subfamilies within Trematosauridae can be identified, the relatively short-nosed

Trematosaurinae Trematosaurinae is a subfamily of temnospondyl amphibians within the family Trematosauridae. Like all trematosaurids, they were marine piscivores, resembling crocodiles in their general build. Unlike the long, almost gharial-like snouts of the ...

and the long-nosed

Lonchorhynchinae Lonchorhynchinae is a subfamily of temnospondyl amphibians within the family Trematosauridae. Classification Below is a cladogram from Steyer (2002) showing the phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον ...

. A third subfamily, Tertreminae, was named in 2000 and includes broad-snouted forms like ''Tirraturhinus''. Below is a cladogram from Steyer (2002) showing the phylogenetic relationships of trematosaurids: A possible trematosaurid has been found in the Toutunhe Formation in the

Junggar Basin The Junggar Basin () is one of the largest sedimentary basins in Northwest China. It is located in Xinjiang, and enclosed by the Tarbagatai Mountains of Kazakhstan in the northwest, the Altai Mountains of Mongolia in the northeast, and the Heave ...

. If this analysis is accurate, it renders Trematosauridae one of the longest lived lineages of

Temnospondyli Temnospondyli (from Greek τέμνειν, ''temnein'' 'to cut' and σπόνδυλος, ''spondylos'' 'vertebra') is a diverse order of small to giant tetrapods—often considered primitive amphibians—that flourished worldwide during the Carb ...

, having lasted as recently as the late Jurassic.(Maisch et al. 2004, p. 582)

References

External links

Trematosauridae
at

Palaeos Palaeos.com is a web site on biology, paleontology, phylogeny and geology and which covers the history of Earth. The site is well respected and has been used as a reference by professional paleontologists such as Michael J. Benton, the professor of ...

Trematosaurids Amphibian families Early Triassic first appearances Carnian extinctions Triassic temnospondyls of Africa Triassic temnospondyls of Asia Triassic temnospondyls of Australia Triassic temnospondyls of Europe {{Temnospondyli-stub