Futabasaurus is a genus of plesiosaur from the Late Cretaceous of Fukushima, Japan. It was described and named in 2006, and was assigned to the family Elasmosauridae. The genus contains one species, F. suzukii.

Description

Life restoration

Futabasaurus has been estimated over 6 metres (20ft) in length, possibly within the range of 6.4–9.2 metres (21–30ft). It can be distinguished from other elasmosaurids by the following characteristics: there is a long distance between the eye sockets and nostrils; the interclavicles and clavicles are fused, and the anterior edge is bent; the humerus is relatively long; and the femora are slim and show prominent muscle scars.

Discovery and naming

Cast of fossils of Futabasaurus suzukii exhibited at the National Museum of Nature and Science, Tokyo, Japan.

Futabasaurus is the first elasmosaurid found in Japan. It was originally known as either "Wellesisaurus suzukii" or "Futaba Suzuki ryu" before publication. The type specimen of Futabasaurus was found in the Irimazawa Member of the Tamayama Formation, in the Futaba Group of Fukushima Prefecture, Japan. The rocks in which it were found date to the Inoceramus amakusensis zone of the early Santonian. The fossils were found by Tadashi Suzuki, then a high school student. Many of the bones of the type specimen show signs of apparent scavenging or predation by sharks, specifically Cretalamna.

The genus Futabasaurus was named after the Futaba Group, in which it was discovered; the specific name is derived from the family name of its discoverer, Suzuki.

The name "Futabasaurus" has also been used for an unrelated theropod dinosaur, from the Late Cretaceous Ashizawa Formation of Japan. However, this dinosaur was not officially named, and remains a nomen nudum.

Classification

Pre-2006 skeletal mount which is informally labelled as "Wellesisaurus suzukii", Moscow Paleontological Museum

The following cladogram shows the placement of Futabasaurus within Elasmosauridae following an analysis by Rodrigo A. Otero, 2016:

Fossils
ElasmosauridaeEromangasaurus carinognathus Callawayasaurus colombiensis Libonectes morgani Tuarangisaurus keyesi Thalassomedon haningtoni CM Zfr 115 Hydrotherosaurus alexandrae Futabasaurus suzukii Aristonectinae Kaiwhekea katiki Alexandronectes zealandiensis Morturneria seymourensis Aristonectes parvidens Aristonectes quiriquinensis Elasmosaurinae Terminonatator pointeixensis Elasmosaurus platyurus Albertonectes vanderveldei Styxosaurus sp. (="Hydralmosaurus serpentinus") Styxosaurus snowii Styxosaurus browni
Eromangasaurus carinognathus
Callawayasaurus colombiensis Libonectes morgani Tuarangisaurus keyesi Thalassomedon haningtoni CM Zfr 115 Hydrotherosaurus alexandrae Futabasaurus suzukii Aristonectinae Kaiwhekea katiki Alexandronectes zealandiensis Morturneria seymourensis Aristonectes parvidens Aristonectes quiriquinensis Elasmosaurinae Terminonatator pointeixensis Elasmosaurus platyurus Albertonectes vanderveldei Styxosaurus sp. (="Hydralmosaurus serpentinus") Styxosaurus snowii Styxosaurus browni
Callawayasaurus colombiensis
Libonectes morgani Tuarangisaurus keyesi Thalassomedon haningtoni CM Zfr 115 Hydrotherosaurus alexandrae Futabasaurus suzukii Aristonectinae Kaiwhekea katiki Alexandronectes zealandiensis Morturneria seymourensis Aristonectes parvidens Aristonectes quiriquinensis Elasmosaurinae Terminonatator pointeixensis Elasmosaurus platyurus Albertonectes vanderveldei Styxosaurus sp. (="Hydralmosaurus serpentinus") Styxosaurus snowii Styxosaurus browni
Libonectes morgani
Tuarangisaurus keyesi Thalassomedon haningtoni CM Zfr 115 Hydrotherosaurus alexandrae Futabasaurus suzukii Aristonectinae Kaiwhekea katiki Alexandronectes zealandiensis Morturneria seymourensis Aristonectes parvidens Aristonectes quiriquinensis Elasmosaurinae Terminonatator pointeixensis Elasmosaurus platyurus Albertonectes vanderveldei Styxosaurus sp. (="Hydralmosaurus serpentinus") Styxosaurus snowii Styxosaurus browni
Tuarangisaurus keyesi Thalassomedon haningtoni
Tuarangisaurus keyesi
Thalassomedon haningtoni
CM Zfr 115 Hydrotherosaurus alexandrae Futabasaurus suzukii
CM Zfr 115
Hydrotherosaurus alexandrae Futabasaurus suzukii
Hydrotherosaurus alexandrae
Futabasaurus suzukii
Aristonectinae Kaiwhekea katiki Alexandronectes zealandiensis Morturneria seymourensis Aristonectes parvidens Aristonectes quiriquinensis Elasmosaurinae Terminonatator pointeixensis Elasmosaurus platyurus Albertonectes vanderveldei Styxosaurus sp. (="Hydralmosaurus serpentinus") Styxosaurus snowii Styxosaurus browni
AristonectinaeKaiwhekea katiki Alexandronectes zealandiensis Morturneria seymourensis Aristonectes parvidens Aristonectes quiriquinensis
Kaiwhekea katiki
Alexandronectes zealandiensis Morturneria seymourensis Aristonectes parvidens Aristonectes quiriquinensis
Alexandronectes zealandiensis
Morturneria seymourensis Aristonectes parvidens Aristonectes quiriquinensis
Morturneria seymourensis
Aristonectes parvidens Aristonectes quiriquinensis
Aristonectes parvidens
Aristonectes quiriquinensis
ElasmosaurinaeTerminonatator pointeixensis Elasmosaurus platyurus Albertonectes vanderveldei Styxosaurus sp. (="Hydralmosaurus serpentinus") Styxosaurus snowii Styxosaurus browni
Terminonatator pointeixensis
Elasmosaurus platyurus Albertonectes vanderveldei Styxosaurus sp. (="Hydralmosaurus serpentinus") Styxosaurus snowii Styxosaurus browni
Elasmosaurus platyurus Albertonectes vanderveldei
Elasmosaurus platyurus
Albertonectes vanderveldei
Styxosaurus sp. (="Hydralmosaurus serpentinus") Styxosaurus snowii Styxosaurus browni
Styxosaurus sp. (="Hydralmosaurus serpentinus")
Styxosaurus snowii Styxosaurus browni
Styxosaurus snowii
Styxosaurus browni

In Popular Culture

In the anime movie, Doraemon: Nobita's Dinosaur, Nobita finds a fossilized futabasaurus egg. Using Doraemon's tools, he makes the egg viable, hatches the egg, and raises it to adulthood before returning it to its time period.

See also

External links

  • (German)