Brachyopoidea
Encyclopedia
Brachyopoidea is a superfamily of temnospondyls that lived during the Mesozoic
. It contains the families
Brachyopidae
and Chigutisauridae
. The earliest records of brachyopids are from the Lower Triassic in Australia
. The latest-surviving member of the superfamily is the chigutisaurid Koolasuchus
from the Early Cretaceous
of Australia.
and Koolasuchus, grew to lengths of around 2.5 metres (8.2 ft). However, an unnamed Late Triassic
or Early Jurassic
brachiopoid from Lesotho
in southern Africa
is estimated to have been far larger. At an estimated 7 metres (23 ft), the brachiopoid from Lesotho is one of the largest amphibians sensu lato ever known. This estimate is based on a single jaw fragment found in 1970 by a French expedition near Alwynskop in Quthing
.
Because of its size, the fragment was initially considered to be from a mastodonsaur
. However, the specimen was redescribed as a brachyopoid in 2005. Several features of the specimen indicate that it is from a brachyopoid. There is a large tusk protruding from the ectopterygoid, a bone of the palate
, and the dental morphology is similar to that of other brachyopoids. When viewed from the side, the upper margin of the jaw appears concave.
of Brachyopoidea adapted from Ruta et al. (2007).
Mesozoic
The Mesozoic era is an interval of geological time from about 250 million years ago to about 65 million years ago. It is often referred to as the age of reptiles because reptiles, namely dinosaurs, were the dominant terrestrial and marine vertebrates of the time...
. It contains the families
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Brachyopidae
Brachyopidae
Brachyopidae is an extinct family of Temnospondyl labyrintodonts. They evolved in the early Mesozoic and were mostly aquatic. A fragmentary find from Lesotho, Africa is estimated to have been 7 meter long, the largest amphibian ever known to have lived besides Prionosuchus.-External links:*...
and Chigutisauridae
Chigutisauridae
Chigutisauridae is an extinct family of large temnospondyl amphibians. The only genera recognized as belonging to Chigutisauridae at the current time are all from Gondwana and include Koolasuchus and Siderops.-References:*Sengupta, D.P. 1995. Palaeontology 38: 19-59.*Sengupta, D.P. 2003...
. The earliest records of brachyopids are from the Lower Triassic in Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
. The latest-surviving member of the superfamily is the chigutisaurid Koolasuchus
Koolasuchus
Koolasuchus is an extinct genus of brachyopoid temnospondyl in the family Chigutisauridae. Fossils have been found from Victoria, Australia and date back 120 Ma to the Aptian stage of the Early Cretaceous. Koolasuchus is the latest known temnospondyl. Koolasuchus is known from several fragments of...
from the Early Cretaceous
Early Cretaceous
The Early Cretaceous or the Lower Cretaceous , is the earlier or lower of the two major divisions of the Cretaceous...
of Australia.
Description
Some large brachiopoids, such as SideropsSiderops
Siderops is an extinct genus of chigutisaurid temnospondyl from Early Jurassic of Australia.It was recently argued that it should be reclassified as a brachyopoid....
and Koolasuchus, grew to lengths of around 2.5 metres (8.2 ft). However, an unnamed Late Triassic
Late Triassic
The Late Triassic is in the geologic timescale the third and final of three epochs of the Triassic period. The corresponding series is known as the Upper Triassic. In the past it was sometimes called the Keuper, after a German lithostratigraphic group that has a roughly corresponding age...
or Early Jurassic
Early Jurassic
The Early Jurassic epoch is the earliest of three epochs of the Jurassic period...
brachiopoid from Lesotho
Lesotho
Lesotho , officially the Kingdom of Lesotho, is a landlocked country and enclave, surrounded by the Republic of South Africa. It is just over in size with a population of approximately 2,067,000. Its capital and largest city is Maseru. Lesotho is a member of the Commonwealth of Nations. The name...
in southern Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
is estimated to have been far larger. At an estimated 7 metres (23 ft), the brachiopoid from Lesotho is one of the largest amphibians sensu lato ever known. This estimate is based on a single jaw fragment found in 1970 by a French expedition near Alwynskop in Quthing
Quthing District
Quthing is a district of Lesotho. It has an area of 2,916 km² and a population in 2006 of approximately 120,502. Quthing, also known as Moyeni, is the capital of the district or camptown, and the only town in the district...
.
Because of its size, the fragment was initially considered to be from a mastodonsaur
Mastodonsauridae
Mastodonsauridae is a family of capitosauroid temnospondyls. Fossils belonging to this family have been found in North America, Greenland, Europe, Asia, and Australia. The family Capitosauridae is synonymous with...
. However, the specimen was redescribed as a brachyopoid in 2005. Several features of the specimen indicate that it is from a brachyopoid. There is a large tusk protruding from the ectopterygoid, a bone of the palate
Palate
The palate is the roof of the mouth in humans and other mammals. It separates the oral cavity from the nasal cavity. A similar structure is found in crocodilians, but, in most other tetrapods, the oral and nasal cavities are not truly separate. The palate is divided into two parts, the anterior...
, and the dental morphology is similar to that of other brachyopoids. When viewed from the side, the upper margin of the jaw appears concave.
Classification
Shown below is a cladogramCladogram
A cladogram is a diagram used in cladistics which shows ancestral relations between organisms, to represent the evolutionary tree of life. Although traditionally such cladograms were generated largely on the basis of morphological characters, DNA and RNA sequencing data and computational...
of Brachyopoidea adapted from Ruta et al. (2007).