''Paracyclotosaurus'' (meaning "Near Wheeled Lizard") is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

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 ...

amphibian Amphibians are tetrapod, four-limbed and ectothermic vertebrates of the Class (biology), class Amphibia. All living amphibians belong to the group Lissamphibia. They inhabit a wide variety of habitats, with most species living within terres ...

, which would have appeared similar to today's

salamander Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All ten ...

– but much larger, measuring up to long and weighing between . It lived in 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 ...

period, about 235 million years ago, and fossils have been found in

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...

, and

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...

. Although they could live on dry land, ''Paracyclotosaurus'' probably spent most of its time in water. They had flattened bodies and elongated heads, almost long, that vaguely resembled those of modern

crocodile Crocodiles (family (biology), family Crocodylidae) or true crocodiles are large semiaquatic reptiles that live throughout the tropics in Africa, Asia, the Americas and Australia. The term crocodile is sometimes used even more loosely to inclu ...

Discovery and naming

The type species ''P. davidi'' is only known from one complete specimen recovered from Australia. It was discovered by quarry miners in a brick pit in St. Peters in Sydney, New South Wales. The discovery, made in 1910, was from a large

ironstone Ironstone is a sedimentary rock, either deposited directly as a ferruginous sediment or created by chemical replacement, that contains a substantial proportion of an iron ore compound from which iron (Fe) can be smelted commercially. Not to be con ...

nodule within

Ashfield Shale Ashfield Shale is part of the Wianamatta group of sedimentary rocks in the Sydney Basin. It lies directly on contemporaneously eroded Hawkesbury sandstone or the Mittagong formation. These rock types were formed in the Triassic Period. It is nam ...

which contained the nearly complete skeleton. The reconstruction was finished in July 1914, and was initially determined to be closely related to ''

Cyclotosaurus ''Cyclotosaurus'' is an extinct genus of temnospondyl within the family Mastodonsauridae. It was of great size for an amphibian, had an elongated skull up to . Etymology The name means "round eared lizard" in Ancient Greek, derived from round ...

''. The original bone of the ''P. davidi'' holotype specimen was in very bad condition, but after the bone was removed from the hard ironstone matrix, casts were made from the matrix mold, and a mold was made from those casts. Casts of the original bone show a fair amount of detail. ''Paracyclotosaurus davidii'' was named after Sir

Edgeworth David Sir Tannatt William Edgeworth David (28 January 1858 – 28 August 1934) was a Welsh Australian geologist and Antarctic explorer. A household name in his lifetime, David's most significant achievements were discovering the major Hunter V ...

, the man who arranged for the

British Museum (Natural History) The Natural History Museum in London is a museum that exhibits a vast range of specimens from various segments of natural history. It is one of three major museums on Exhibition Road in South Kensington, the others being the Science Museum an ...

to acquire the specimen.

References

* Patricia Vickers-Rich and Thomas Hewett Rich 1993, Wildlife of Gondwana, Reed.

External links

The Paleobiology Database: ''Paracyclotosaurus''Paracyclotosaurus davidi at the Natural History Museum
{{Taxonbar, from=Q977782 Triassic temnospondyls of Asia Triassic temnospondyls of Africa Triassic temnospondyls of Australia Prehistoric vertebrates of Oceania Prehistoric tetrapod genera Fossil taxa described in 1958 Prehistoric amphibian genera