''Madygenerpeton'' is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

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 ...

of chroniosuchid

reptiliomorph Reptiliomorpha (meaning reptile-shaped; in PhyloCode known as ''Pan-Amniota'') is a clade containing the amniotes and those tetrapods that share a more recent common ancestor with amniotes than with living amphibians (lissamphibians). It was defi ...

from 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 a ...

Madygen Formation The Madygen Formation (Russian language, Russian: Madygen Svita) is a Middle Triassic, Middle–Late Triassic (Ladinian–Carnian) geologic formation and lagerstätte in the Batken Region, Batken and Osh Regions of western Kyrgyzstan, with minor ...

Kyrgyzstan Kyrgyzstan, officially the Kyrgyz Republic, is a landlocked country in Central Asia lying in the Tian Shan and Pamir Mountains, Pamir mountain ranges. Bishkek is the Capital city, capital and List of cities in Kyrgyzstan, largest city. Kyrgyz ...

. It was first named by paleontologists Rainer R. Schoch, Sebastian Voigt and Michael Buchwitz in

2010 The year saw a multitude of natural and environmental disasters such as the 2010 Haiti earthquake, the Deepwater Horizon oil spill, and the 2010 Chile earthquake. The 2009 swine flu pandemic, swine flu pandemic which began the previous year ...

from a nearly complete

skull The skull, or cranium, is typically a bony enclosure around the brain of a vertebrate. In some fish, and amphibians, the skull is of cartilage. The skull is at the head end of the vertebrate. In the human, the skull comprises two prominent ...

and associated

osteoderm Osteoderms are bony deposits forming scales, plates, or other structures based in the dermis. Osteoderms are found in many groups of extant and extinct reptiles and amphibians, including lizards, crocodilians, frogs, temnospondyls (extinct amph ...

s. The

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

is ''M. pustulatus''.

Description

''Madygenerpeton'', like other chroniosuchids, has

s, or bony plates, overlying its spine. These osteoderms interlock with each other and connect to their associated vertebrae on the spinal column. They are wide and have curved or peaked surfaces. On the upper surface of the front end and the lower surface of the back end of each osteoderm there are facets covered in concentric ridges and furrows. These facets allow the plates to interlock with each other. The relatively narrow width of the osteoderms in ''Madygenerpeton'' allow for more lateral flexion in the trunk of than other chroniosuchids, up to 7.5°. The skull has a parabolic outline and its surface is covered with pustular ornamentation. This distinctive ornamentation gives the type species its name, ''M. pustulatus''. Unlike other chroniosuchids, ''Madygenerpeton'' lacks an antorbital

fontanelle A fontanelle (or fontanel) (colloquially, soft spot) is an anatomical feature of the infant human skull comprising soft membranous gaps ( sutures) between the cranial bones that make up the calvaria of a fetus or an infant. Fontanelles allow ...

in front of the eyes. The postparietal or posterior area of the skull is concave.

Paleobiology

The tightly interlocking osteoderms along the back of

Permian The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years, from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.902 Mya. It is the s ...

chroniosuchians were likely an adaptation to terrestrial locomotion. The plates made the vertebral column more rigid, allowing it to better cope with stresses from

shearing Sheep shearing is the process by which the woollen fleece of a sheep is cut off. The person who removes the sheep's wool is called a '' shearer''. Typically each adult sheep is shorn once each year (depending upon dialect, a sheep may be sai ...

torsion Torsion may refer to: Science * Torsion (mechanics), the twisting of an object due to an applied torque * Torsion of spacetime, the field used in Einstein–Cartan theory and ** Alternatives to general relativity * Torsion angle, in chemistry Bio ...

compression Compression may refer to: Physical science *Compression (physics), size reduction due to forces *Compression member, a structural element such as a column *Compressibility, susceptibility to compression * Gas compression *Compression ratio, of a ...

, and tension. However, the increased stability of the vertebral column resulted in less flexibility. In ''Madygenerpeton'', the increased flexibility of the trunk may have been an adaptation to a secondarily aquatic lifestyle. Greater lateral flexion would have enabled lateral undulation useful for swimming.

References

{{Taxonbar, from=Q6728882 Chroniosuchia Late Triassic tetrapods of Asia Carnian genera Fossils of Kyrgyzstan Fossil taxa described in 2010