Tzaganosuchus
Encyclopedia
Tzaganosuchus
is an extinct genus
of fossil
crocodile
from the Gobi Desert
of southern/southeastern Mongolia
. The type and only known
species
for this genus, Tzaganosuchus infansis was discovered during a joint paleontological
expedition conducted by the Soviet Union
and Mongolia. That same expedition also described several other reptiles including several species of Shamosuchus
and the archosaur
genus Irenosaurus
(originally named Tchoiria
egloni). The prefix of the name "Tzaganosuchus" is a Mongol
word derived from the locality where its fossils were first found: the Tsagan Khushu Quarry, which dates to the Paleogene
epoch
(Thanetian
stratigraphic stage) and is part of the Naran-Bulak Formation. The suffix suchus is a Latin word for crocodile.
and virtually all extant crocodile species and is the largest the three Crocodylidae subfamilies.
, as well as several fossil species that have only recently (from the standpoint of geologic time) become extinct, such as Rimasuchus
or Voay
. Therefore, Tzaganosuchus must retain several traits common to these groups, such as the long, pointed snout, amphibious lifestyle, and so on.
age of Asian land mammals, which Tzangosuchus may have preyed upon.
Tzaganosuchus
Tzaganosuchus is an extinct genus of fossil crocodile from the Gobi Desert of southern/southeastern Mongolia. The type and only known species for this genus, Tzaganosuchus infansis was discovered during a joint paleontological expedition conducted by the Soviet Union and Mongolia...
is an extinct genus
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 fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
crocodile
Crocodile
A crocodile is any species belonging to the family Crocodylidae . The term can also be used more loosely to include all extant members of the order Crocodilia: i.e...
from the Gobi Desert
Gobi Desert
The Gobi is a large desert region in Asia. It covers parts of northern and northwestern China, and of southern Mongolia. The desert basins of the Gobi are bounded by the Altai Mountains and the grasslands and steppes of Mongolia on the north, by the Hexi Corridor and Tibetan Plateau to the...
of southern/southeastern Mongolia
Mongolia
Mongolia is a landlocked country in East and Central Asia. It is bordered by Russia to the north and China to the south, east and west. Although Mongolia does not share a border with Kazakhstan, its western-most point is only from Kazakhstan's eastern tip. Ulan Bator, the capital and largest...
. The type and only known
Monotypic
In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...
species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
for this genus, Tzaganosuchus infansis was discovered during a joint paleontological
Paleontology
Paleontology "old, ancient", ὄν, ὀντ- "being, creature", and λόγος "speech, thought") is the study of prehistoric life. It includes the study of fossils to determine organisms' evolution and interactions with each other and their environments...
expedition conducted by the Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
and Mongolia. That same expedition also described several other reptiles including several species of Shamosuchus
Shamosuchus
Shamosuchus is an extinct genus of neosuchian crocodile that lived during the Late Cretaceous period in what is now the Gobi desert of Mongolia, approximately 85 to 65 million years ago. The teeth were adapted to crush bivalves, gastropods and other animals with a shell or exoskeleton . The genus...
and the archosaur
Archosaur
Archosaurs are a group of diapsid amniotes whose living representatives consist of modern birds and crocodilians. This group also includes all extinct non-avian dinosaurs, many extinct crocodilian relatives, and pterosaurs. Archosauria, the archosaur clade, is a crown group that includes the most...
genus Irenosaurus
Irenosaurus
Irenosaurus is a genus of choristodere, a type of amphibious reptile. It is known from a single fragmentary postcranial skeleton , discovered in the Aptian-age Lower Cretaceous Hühteeg Formation at Hüren Dukh, central Mongolia. The type species is I...
(originally named Tchoiria
Tchoiria
Tchoiria is a genus of simoedosaurid choristodere, a type of crocodile-like aquatic reptile. Fossils of this genus have been found in Early Cretaceous-age rocks in Mongolia. Four species have been named, but two have been given their own genera. The type species is T...
egloni). The prefix of the name "Tzaganosuchus" is a Mongol
Mongolian language
The Mongolian language is the official language of Mongolia and the best-known member of the Mongolic language family. The number of speakers across all its dialects may be 5.2 million, including the vast majority of the residents of Mongolia and many of the Mongolian residents of the Inner...
word derived from the locality where its fossils were first found: the Tsagan Khushu Quarry, which dates to the Paleogene
Paleogene
The Paleogene is a geologic period and system that began 65.5 ± 0.3 and ended 23.03 ± 0.05 million years ago and comprises the first part of the Cenozoic Era...
epoch
Epoch (geology)
An epoch is a subdivision of the geologic timescale based on rock layering. In order, the higher subdivisions are periods, eras and eons. We are currently living in the Holocene epoch...
(Thanetian
Thanetian
The Thanetian is, in the ICS' Geologic timescale, the latest age or uppermost stratigraphic stage of the Paleocene Epoch or series. It spans the time between and . The Thanetian is preceded by the Selandian age and followed by the Ypresian age...
stratigraphic stage) and is part of the Naran-Bulak Formation. The suffix suchus is a Latin word for crocodile.
Taxonomy
When it was described in 1983, along with a number of other reptile species, Tzaganosuchus was put in the subfamily Crocodylinae, which contains the genus CrocodylusCrocodylus
Crocodylus is one of three genera from the Crocodylinae subfamily extending from the Crocodylidae family.Established species include three extinct species:* † Crocodylus acer - probably represents a distinct genus....
and virtually all extant crocodile species and is the largest the three Crocodylidae subfamilies.
Description
Based purely on its taxonomic location, it is clear that Tzaganosuchus is closely related to many modern crocodile species, such as the Nile CrocodileNile crocodile
The Nile crocodile or Common crocodile is an African crocodile which is common in Somalia, Ethiopia, Uganda, Kenya, Egypt, Tanzania, Zambia, Zimbabwe, Gabon, South Africa, Malawi, Sudan, Botswana, and Cameroon...
, as well as several fossil species that have only recently (from the standpoint of geologic time) become extinct, such as Rimasuchus
Rimasuchus
Rimasuchus is an extinct genus of crocodile from the Neogene period of Africa and the Middle East. Its name comes from the Latin words rima, meaning "crack" and suchus, which means "crocodile"...
or Voay
Voay
Voay is an extinct genus of crocodylid crocodilian. Numerous subfossils have been found from Madagascar, including complete skulls as well as vertebrae and osteoderms from such places as Ambolisatra and Antsirabe. The genus is thought to have become extinct relatively recently during the Holocene...
. Therefore, Tzaganosuchus must retain several traits common to these groups, such as the long, pointed snout, amphibious lifestyle, and so on.
Distribution and habitat
Tzanganosuchus lived in the Gobi during the Paleocene–Eocene Thermal Maximum, a time of increased temperature and humidity worldwide, that was most extreme during the last stages of the Paleocene. The time in which this crocodile lived also corresponds closely to the GashatanGashatan
The Gashatan is an Asian Land Mammal Age, a large biozone which corresponds to ages between 58.7—55.8 Ma for finds of fossil mammals in Asia. This zone lies within the Thanetian stage of the Paleocene series. It precedes the Bumbanian....
age of Asian land mammals, which Tzangosuchus may have preyed upon.