Futabasaurus
Encyclopedia
Futabasaurus is a genus
of plesiosaur
from the Late Cretaceous
of Fukushima
, Japan
. Described and named in 2006
, it was assigned to the family Elasmosauridae
. The length was about 7 m, and the weight was about 3~4 tons. Futabasaurus is the first elasmosaurid found in Japan. The type species
is F. suzukii. Many of the bones of the type specimen
show apparent scavenging or predation by sharks.
The name "Futabasaurus" also appears in connection with a theropod dinosaur
, also from the Late Cretaceous of Japan. However, this dinosaur
was not officially named, so the dinosaur "Futabasaurus" is a nomen nudum
when applied to this theropod. It is not the same as the plesiosaur named Futabasaurus.
, and futaba from the Futaba Group.
, Futaba Group
, Fukushima Prefecture, Japan, dating to the Inoceramus amakusensis zone of the early Santonian
. The fossils were found by Tadashi Suzuki, a high school student around that time.
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 plesiosaur
Plesiosaur
Plesiosauroidea is an extinct clade of carnivorous plesiosaur marine reptiles. Plesiosauroids, are known from the Jurassic and Cretaceous Periods...
from the Late Cretaceous
Late Cretaceous
The Late Cretaceous is the younger of two epochs into which the Cretaceous period is divided in the geologic timescale. Rock strata from this epoch form the Upper Cretaceous series...
of Fukushima
Fukushima Prefecture
is a prefecture of Japan located in the Tōhoku region on the island of Honshu. The capital is the city of Fukushima.-History:Until the Meiji Restoration, the area of Fukushima prefecture was known as Mutsu Province....
, Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
. Described and named in 2006
2006 in paleontology
-Insects:-Tetrapodomorphs:-Newly named temnospondylians:-Newly named amphibians:-Ichthyosaurs:-Newly named basal lepidosauromorphs:-Newly named plesiosaurs:-Newly named squamates:-Newly named crurotarsans:-Newly named dinosaurs:...
, it was assigned to the family Elasmosauridae
Elasmosauridae
Elasmosauridae was the family of plesiosaurs. They had the longest necks of the plesiosaurs and survived from the Late Triassic to the end of the Cretaceous. They had a diet of fish and shelless cephalopods.-Size:...
. The length was about 7 m, and the weight was about 3~4 tons. Futabasaurus is the first elasmosaurid found in Japan. 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 F. suzukii. Many of the bones of the type specimen
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...
show apparent scavenging or predation by sharks.
The name "Futabasaurus" also appears in connection with a theropod dinosaur
Dinosaur
Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...
, also from the Late Cretaceous of Japan. However, this dinosaur
Futabasaurus (dinosaur)
"Futabasaurus" is an informal name for a genus of theropod dinosaur from the Late Cretaceous of Japan, known only from a partial shin bone discovered in the Coniacian-age Ashizawa Formation of the Futaba Group. It was coined by David Lambert in 1990 as a conversion from the Japanese nickname...
was not officially named, so the dinosaur "Futabasaurus" is a nomen nudum
Nomen nudum
The phrase nomen nudum is a Latin term, meaning "naked name", used in taxonomy...
when applied to this theropod. It is not the same as the plesiosaur named Futabasaurus.
Etymology
Futabasaurus suzukii was named from the family name of discover SuzukiSuzuki
is a Japanese multinational corporation headquartered in Hamamatsu, Japan that specializes in manufacturing compact automobiles and 4x4 vehicles, a full range of motorcycles, all-terrain vehicles , outboard marine engines, wheelchairs and a variety of other small internal combustion engines...
, and futaba from the Futaba Group.
Discovery
The first fossils of Futabasaurus were found in the Irimazawa Member of the Tamayama FormationTamayama Formation
The Tamayama Formation is a Mesozoic geologic formation. Dinosaur remains diagnostic to the genus level are among the fossils that have been recovered from the formation.-See also:* List of dinosaur-bearing rock formations...
, Futaba Group
Futaba Group
The Futaba Group is a Mesozoic geologic formation. Dinosaur remains are among the fossils that have been recovered from the formation, although none have yet been referred to a specific genus.-See also:* List of dinosaur-bearing rock formations...
, Fukushima Prefecture, Japan, dating to the Inoceramus amakusensis zone of the early Santonian
Santonian
The Santonian is an age in the geologic timescale or a chronostratigraphic stage. It is a subdivision of the Late Cretaceous epoch or Upper Cretaceous series. It spans the time between 85.8 ± 0.7 mya and 83.5 ± 0.7 mya...
. The fossils were found by Tadashi Suzuki, a high school student around that time.
Characteristics
- Long distance between the eye sockets and nostrils.
- InterclavicleInterclavicleAn interclavicle is a bone which, in most tetrapods, is located between the clavicles. Therian mammals are the only tetrapods which never have an interclavicle, although some members of other groups also lack one. Monotremes, although part of the mammalian class, do have interclavicles...
s and clavicles are fused and the anteriorAnatomical terms of locationStandard anatomical terms of location are designations employed in science that deal with the anatomy of animals to avoid ambiguities that might otherwise arise. They are not language-specific, and thus require no translation...
edge is bent. - Relatively long upper armHumerusThe humerus is a long bone in the arm or forelimb that runs from the shoulder to the elbow....
- Slim thigh boneFemurThe femur , or thigh bone, is the most proximal bone of the leg in tetrapod vertebrates capable of walking or jumping, such as most land mammals, birds, many reptiles such as lizards, and amphibians such as frogs. In vertebrates with four legs such as dogs and horses, the femur is found only in...
s with a significant muscle scar.
External links
- Futabasaurus at Dinosaurier-Web (German)