Dorosuchus
Encyclopedia
Dorosuchus is an extinct genus
of archosauriform that is possibly a member of the family
Euparkeriidae
. It lived during the Anisian
stage of the Middle Triassic
. Fossil material is known from Sol-Iletsk
in Orenburg Oblast
, Russia
. The type species
is D. neoetus, named in 1989.
, sharing many features in the limbs and pelvic girdle. Most specimens are known from a single block of siltstone
from a location known as the Berdyanka I locality. Limb and hip elements, sacral
and caudal vertebrae, and a braincase are preserved in the block and represent four individuals. A partial illium is known from another locality.
of South Africa
. Several other genera have been assigned to the family and include Turfanosuchus
, Halazaisuchus, and Wangisuchus. However, most of these genera have been excluded from the family on the basis of anatomical features such as those found in the ankle
(e.g. Turfanosuchus and Wangisuchus) or are known from specimens that are too poorly preserved to offer many features that could include them within the family (e.g. Halazbaisuchus and Wangisuchus). Doubts have also been raised about the assignment of Dorosuchus to the family Euparkeriidae because of a lack of defining characteristics. Despite this, Dorosuchus is usually considered to be a euparkeriid, along with the genera Euparkeria and Osmolskina
.
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 archosauriform that is possibly a member of the family
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...
Euparkeriidae
Euparkeriidae
Euparkeriidae is a family of small basal archosauromorph carnivores which lived from the Early Triassic to the Middle Triassic . Their fossil remains are known so far from South Africa and Russia...
. It lived during the Anisian
Anisian
In the geologic timescale, the Anisian is the lower stage or earliest age of the Middle Triassic series or epoch and lasted from 245 million years ago until 237 million years ago, approximately...
stage of the Middle Triassic
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. It spans the time between 245 ± 1.5 Ma and 228 ± 2 Ma...
. Fossil material is known from Sol-Iletsk
Sol-Iletsk
Sol-Iletsk is a town in Orenburg Oblast, Russia, located on the right bank of the Ilek River , south of Orenburg. Population: 22,000 ; 11,802 ....
in Orenburg Oblast
Orenburg Oblast
Orenburg Oblast is a federal subject of Russia . Its administrative center is the city of Orenburg. From 1938 to 1957, it bore the name Chkalov Oblast in honor of Valery Chkalov...
, Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
. 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 D. neoetus, named in 1989.
Description
Dorosuchus is similar in appearance to the euparkeriid EuparkeriaEuparkeria
Euparkeria was a small African reptile of the early Triassic period between 248-245 million years ago, close to the ancestry of the archosaurs.- Palaeobiology :...
, sharing many features in the limbs and pelvic girdle. Most specimens are known from a single block of siltstone
Siltstone
Siltstone is a sedimentary rock which has a grain size in the silt range, finer than sandstone and coarser than claystones.- Description :As its name implies, it is primarily composed of silt sized particles, defined as grains 1/16 - 1/256 mm or 4 to 8 on the Krumbein phi scale...
from a location known as the Berdyanka I locality. Limb and hip elements, sacral
Sacrum
In vertebrate anatomy the sacrum is a large, triangular bone at the base of the spine and at the upper and back part of the pelvic cavity, where it is inserted like a wedge between the two hip bones. Its upper part connects with the last lumbar vertebra, and bottom part with the coccyx...
and caudal vertebrae, and a braincase are preserved in the block and represent four individuals. A partial illium is known from another locality.
Classification
Dorosuchus was initially classified as a euparkeriid in 1989 with its first description. The family Euparkeriidae is best represented by the genus Euparkeria from the Early TriassicEarly Triassic
The Early Triassic is the first of three epochs of the Triassic period of the geologic timescale. It spans the time between 251 ± 0.4 Ma and 245 ± 1.5 Ma . Rocks from this epoch are collectively known as the Lower Triassic, which is a unit in chronostratigraphy...
of South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
. Several other genera have been assigned to the family and include Turfanosuchus
Turfanosuchus
Turfanosuchus is a genus of archosauriform reptile which lived during the Middle Triassic of northwestern China. The type species, T. dabanensis, was described by C.C. Young in 1973, based on a partially complete but disarticulated fossil skeleton...
, Halazaisuchus, and Wangisuchus. However, most of these genera have been excluded from the family on the basis of anatomical features such as those found in the ankle
Ankle
The ankle joint is formed where the foot and the leg meet. The ankle, or talocrural joint, is a synovial hinge joint that connects the distal ends of the tibia and fibula in the lower limb with the proximal end of the talus bone in the foot...
(e.g. Turfanosuchus and Wangisuchus) or are known from specimens that are too poorly preserved to offer many features that could include them within the family (e.g. Halazbaisuchus and Wangisuchus). Doubts have also been raised about the assignment of Dorosuchus to the family Euparkeriidae because of a lack of defining characteristics. Despite this, Dorosuchus is usually considered to be a euparkeriid, along with the genera Euparkeria and Osmolskina
Osmolskina
Osmolskina is a genus of archosauriform reptile which lived during the Early Triassic in what is now Poland. The type species, Osmolskina czatkowicensis, was described by Magdalena Borsuk−Białynicka and Susan Evans in 2003. The generic name honors the late female Polish paleontologist Halszka...
.