Eastmanosteus
Encyclopedia
Eastmanosteus is a fossil genus of dinichthyid placoderms. It was closely related to the giant Dunkleosteus
, but differed from that genus in possessing a distinctive tuberculated bone ornament, a differently shaped nuchal plate and a more zig-zagging course of the sutures of the skull roof.
Species of Eastmanosteus had powerful jaws with sharp cutting edges and were likely active predators. Fossils have been found in many parts of the world in marine sediments dating from the Middle to Late Devonian
. They were medium-to-large fish, with specimens E. pustulosus and E. licharevi approaching a total length of 3 metres. Complete exoskeletons with soft-tissue traces of E. calliaspis from Australia make this one of the best known dinichthyids.
From the Frasnian
Gogo Formation
of northwestern Western Australia
. This is the best known member of the genus with many articulated skulls and trunk armours in museum collections. Evidence of muscle fibres, circulatory structures and nerve tissue have been preserved representing some of the oldest known gnathostome soft tissue. The largest known skull is 272mm in length suggesting a total size of roughly 1.5m. It was one of the largest fish in the Gogo assemblage.
A poorly known species from Russia, originally described from an isolated nuchal plate from the Frasnian of Timman with additional material from the Famennian
of Lipetsk
.
A medium sized species from the Eifelian of south-central Manitoba
, Canada
. One of the earliest and most completely known members of the genus.
Based on a single almost complete head shield from the Late Devonian of New York State, USA. Has previously been assigned to Dinicthys and Dunkleosteus.
This is the type species and was originally placed in the genus Dinichthys. It was a large and widely distributed form, with fossil material from the Middle-Late Devonian of the USA (Wisconsin, Iowa, Michigan, New York State) and the Frasnian of Poland.
Originally assigned to Dunkleosteus. From the Middle Devonian of Yunnan
Province, China
.
An undescribed species based on relatively well preserved material from the Frasnian of
Kerman
, East Iran
.
Morocco, and the USA. Most of these are either indeterminate dinichthyids or are now placed in different genera.
Dunkleosteus
Dunkleosteus is a genus of prehistoric fish, one of the largest arthrodire placoderms ever to have lived, existing during the Late Devonian period, about 380-360 million years ago.This hunter, measuring up to and weighing , was a hypercarnivorous apex predator...
, but differed from that genus in possessing a distinctive tuberculated bone ornament, a differently shaped nuchal plate and a more zig-zagging course of the sutures of the skull roof.
Species of Eastmanosteus had powerful jaws with sharp cutting edges and were likely active predators. Fossils have been found in many parts of the world in marine sediments dating from the Middle to Late Devonian
Devonian
The Devonian is a geologic period and system of the Paleozoic Era spanning from the end of the Silurian Period, about 416.0 ± 2.8 Mya , to the beginning of the Carboniferous Period, about 359.2 ± 2.5 Mya...
. They were medium-to-large fish, with specimens E. pustulosus and E. licharevi approaching a total length of 3 metres. Complete exoskeletons with soft-tissue traces of E. calliaspis from Australia make this one of the best known dinichthyids.
Species
- Eastmanosteus calliapsis Dennis-Bryan 1987
From the Frasnian
Frasnian
The Frasnian is one of two faunal stages in the Late Devonian epoch. It lasted from 385.3 ± 2.6 million years ago to 374.5 ± 2.6 million years ago. It was preceded by the Givetian stage and followed by the Famennian stage...
Gogo Formation
Gogo Formation
The Gogo Formation in the Kimberley region of Western Australia is a Lagerstätte that exhibits exceptional preservation of a Devonian reef community.- Sedimentology :...
of northwestern Western Australia
Western Australia
Western Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...
. This is the best known member of the genus with many articulated skulls and trunk armours in museum collections. Evidence of muscle fibres, circulatory structures and nerve tissue have been preserved representing some of the oldest known gnathostome soft tissue. The largest known skull is 272mm in length suggesting a total size of roughly 1.5m. It was one of the largest fish in the Gogo assemblage.
- Eastmanosteus licharevi (Obrucheva 1956)
A poorly known species from Russia, originally described from an isolated nuchal plate from the Frasnian of Timman with additional material from the Famennian
Famennian
The Famennian is one of two faunal stages in the Late Devonian epoch. It lasted from 374.5 ± 2.6 million years ago to 359.2 ± 2.5 million years ago. It was preceded by the Frasnian stage and followed by the Tournaisian stage and is named after Famenne, a natural region in southern Belgium.It was...
of Lipetsk
Lipetsk
Lipetsk is a city and the administrative center of Lipetsk Oblast, Russia, located on the banks of the Voronezh River in the Don basin, southeast of Moscow.-History:...
.
- Eastmanosteus lundarensis Hanke, Stewart and Lammers 1996
A medium sized species from the Eifelian of south-central Manitoba
Manitoba
Manitoba is a Canadian prairie province with an area of . The province has over 110,000 lakes and has a largely continental climate because of its flat topography. Agriculture, mostly concentrated in the fertile southern and western parts of the province, is vital to the province's economy; other...
, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
. One of the earliest and most completely known members of the genus.
- Eastmanosteus magnificus (Hussakof & Bryant 1918)
Based on a single almost complete head shield from the Late Devonian of New York State, USA. Has previously been assigned to Dinicthys and Dunkleosteus.
- Eastmanosteus pustulosus (Eastman 1897)
This is the type species and was originally placed in the genus Dinichthys. It was a large and widely distributed form, with fossil material from the Middle-Late Devonian of the USA (Wisconsin, Iowa, Michigan, New York State) and the Frasnian of Poland.
- Eastmanosteus yunnanensis (Wang 1982)
Originally assigned to Dunkleosteus. From the Middle Devonian of Yunnan
Yunnan
Yunnan is a province of the People's Republic of China, located in the far southwest of the country spanning approximately and with a population of 45.7 million . The capital of the province is Kunming. The province borders Burma, Laos, and Vietnam.Yunnan is situated in a mountainous area, with...
Province, China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
.
- Eastmanosteus species 1 Janvier
An undescribed species based on relatively well preserved material from the Frasnian of
Kerman
Kerman
- Geological characteristics :For the Iranian paleontologists, Kerman has always been considered a fossil paradise. Finding new dinosaur footprints in 2005 has now revealed new hopes for paleontologists to better understand the history of this area.- Economy :...
, East Iran
Iran
Iran , officially the Islamic Republic of Iran , is a country in Southern and Western Asia. The name "Iran" has been in use natively since the Sassanian era and came into use internationally in 1935, before which the country was known to the Western world as Persia...
.
- Many other species have been included within this genus based on material from Russia,
Morocco, and the USA. Most of these are either indeterminate dinichthyids or are now placed in different genera.