Malerisaurus
Encyclopedia
Malerisaurus is an extinct genus
of prolacertiform archosauromorph known from Andhra Pradesh
of India
and Texas
of the USA.
ISIR 150, two articulate
d and almost complete skeleton
s which were discovered as the presumable gastric contents of two skeletons of Parasuchus hislopi. It was collected from the Lower Maleri Formation
, dating to the late Carnian
or early Norian
stage of the Late Triassic
. Malerisaurus robinsonae was a small archosauromorph, probably capable of climbing trees and swimming. The skull has some adaptations to a carnivorous diet, but is nevertheless unspecialised and probably more of an insectivore. Malerisaurus, seen as a diapsid
skull, shows primitive and advanced facies in its unossified laterosphenoid, absence of antorbital and mandibular
fenestrae
, gracile form, primitive girdles, elongated cervicals and absence of dermal armour. The suborder Prolacertiformes
currently represents four families: Sharovipterygidae, Protorosauridae, Prolacertidae and Tanystropheidae. Chatterjee provisionally regarded Malerisaurus as close to Protorosaurus
.
A second species, M. langstoni, is known from the holotype
TMM
31099-11, a partial but poorly preserved skeleton
. It was collected in the Otis Chalk Quarry 2 (TMM 31099 locality) from the Colorado City Formation, Chinle Group, dating to the early Carnian
stage of the Late Triassic
, about 228-227.5 million years ago. It was found in the Howard County
of Texas.
and the type species
is Malerisaurus robinsonae. A second species, M. langstoni, was named by him in 1986
. The generic name is derived from the name of the Lower Maleri Formation
, where the holotype of the type species was collected, and sauros, Greek
for "lizard". The specific name of M. langstoni honors the American paleontologist and professor Wann Langston, Jr.
.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of prolacertiform archosauromorph known from Andhra Pradesh
Andhra Pradesh
Andhra Pradesh , is one of the 28 states of India, situated on the southeastern coast of India. It is India's fourth largest state by area and fifth largest by population. Its capital and largest city by population is Hyderabad.The total GDP of Andhra Pradesh is $100 billion and is ranked third...
of India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
and Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
of the USA.
Description
Malerisaurus is known from the holotypeHolotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
ISIR 150, two articulate
Articulate
Articulate may refer to:*Articulate *Articulate sign*Articulate sound*Joint, also known as articulation*Word modified by an article...
d and almost complete skeleton
Skeleton
The skeleton is the body part that forms the supporting structure of an organism. There are two different skeletal types: the exoskeleton, which is the stable outer shell of an organism, and the endoskeleton, which forms the support structure inside the body.In a figurative sense, skeleton can...
s which were discovered as the presumable gastric contents of two skeletons of Parasuchus hislopi. It was collected from the Lower Maleri Formation
Lower Maleri Formation
The Lower Maleri Formation is a sedimentary rock formation found in Andhra Pradesh, India. It is the lowermost member of the Pranhita–Godavari Basin. It is of late Carnian to early Norian age , and is notable for its fossils of early dinosaurs, including the basal saurischian ...
, dating to the late Carnian
Carnian
The Carnian is the lowermost stage of the Upper Triassic series . It lasted from about 228.7 till 216.5 million years ago . The Carnian is preceded by the Ladinian and is followed by the Norian...
or early Norian
Norian
The Norian is a division of the Triassic geological period. It has the rank of an age or stage . The Norian lasted from 216.5 ± 2.0 to 203.6 ± 1.5 million years ago. It was preceded by the Carnian and succeeded by the Rhaetian.-Stratigraphic definitions:The Norian was named after the Noric Alps in...
stage of the 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...
. Malerisaurus robinsonae was a small archosauromorph, probably capable of climbing trees and swimming. The skull has some adaptations to a carnivorous diet, but is nevertheless unspecialised and probably more of an insectivore. Malerisaurus, seen as a diapsid
Diapsid
Diapsids are a group of reptiles that developed two holes in each side of their skulls, about 300 million years ago during the late Carboniferous period. Living diapsids are extremely diverse, and include all crocodiles, lizards, snakes, and tuatara...
skull, shows primitive and advanced facies in its unossified laterosphenoid, absence of antorbital and mandibular
Mandibular
Mandibular may refer to:* Mandible, the lower jaw bone* Mandibular canal* Mandibular nerve...
fenestrae
Fenestrae
Fenestræ is a Latin word that means "window".* In histology, fenestræ are small pores in endothelial cells that allow for rapid exchange of molecules between sinusoid blood vessels and surrounding tissue...
, gracile form, primitive girdles, elongated cervicals and absence of dermal armour. The suborder Prolacertiformes
Prolacertiformes
Prolacertiformes were an order of archosauromorph reptiles that lived during the Permian and Triassic Periods...
currently represents four families: Sharovipterygidae, Protorosauridae, Prolacertidae and Tanystropheidae. Chatterjee provisionally regarded Malerisaurus as close to Protorosaurus
Protorosaurus
Protorosaurus , a lizard-like reptile of the order Prolacertiformes, is the earliest known archosauromorph. It lived during the Late Permian period in Germany. In 1914, a new ceratopsian dinosaur found by Lawrence Lambe was again given the name Protorosaurus...
.
A second species, M. langstoni, is known from the holotype
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
TMM
TMM
TMM is a three letter acronym that may refer to:* The Mythical Man Month, the seminal book about management of software development* Tokyo Mew Mew, a Japanese anime and manga series* Turkmenistani manat, the currency of Turkmenistan...
31099-11, a partial but poorly preserved skeleton
Skeleton
The skeleton is the body part that forms the supporting structure of an organism. There are two different skeletal types: the exoskeleton, which is the stable outer shell of an organism, and the endoskeleton, which forms the support structure inside the body.In a figurative sense, skeleton can...
. It was collected in the Otis Chalk Quarry 2 (TMM 31099 locality) from the Colorado City Formation, Chinle Group, dating to the early Carnian
Carnian
The Carnian is the lowermost stage of the Upper Triassic series . It lasted from about 228.7 till 216.5 million years ago . The Carnian is preceded by the Ladinian and is followed by the Norian...
stage of the 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...
, about 228-227.5 million years ago. It was found in the Howard County
Howard County
Howard County is the name of seven counties in the United States of America:* Howard County, Arkansas, named for James H. Howard, Arkansas state senator* Howard County, Indiana, named for Tilghman Ashurst Howard, U.S. Representative from Indiana...
of Texas.
Etymology
Malerisaurus was named by Sankar Chatterjee in 19801980 in paleontology
-Newly named dinosaurs:Data courtesy of George Olshevsky's dinosaur genera list and Dr. Jeremy Montague's dinosaur genus database.-New taxa:-New taxa:-Non-mammalian:-References:...
and the type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
is Malerisaurus robinsonae. A second species, M. langstoni, was named by him in 1986
1986 in paleontology
-Newly named dinosaurs:Data courtesy of George Olshevsky's dinosaur genera list and Dr. Jeremy Montague's dinosaur genus database.-New taxa:-Pterosaurs:...
. The generic name is derived from the name of the Lower Maleri Formation
Lower Maleri Formation
The Lower Maleri Formation is a sedimentary rock formation found in Andhra Pradesh, India. It is the lowermost member of the Pranhita–Godavari Basin. It is of late Carnian to early Norian age , and is notable for its fossils of early dinosaurs, including the basal saurischian ...
, where the holotype of the type species was collected, and sauros, Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
for "lizard". The specific name of M. langstoni honors the American paleontologist and professor Wann Langston, Jr.
Wann Langston, Jr.
Wann Langston, Jr. is an American paleontologist and professor at the University of Texas at Austin. He has worked on a number of different reptiles and amphibians in his long career, beginning with the 1950 description of the theropod dinosaur Acrocanthosaurus...
.