Seeleyosaurus
Seeleyosaurus was a plesiosaur, a long-necked marine reptile that swam in the Jurassic seas. It had four flippers like paddles and a mouth full of sharp teeth for catching fish. This reptile lived about 183 million years ago in the warm waters of what is now Germany.31
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Fun facts
Seeleyosaurus had a skull about 17 centimeters (6.7 inches) long, with five teeth in the upper jaw and up to 20 teeth in the lower jaw.1
Its flippers were long, making up about 25 percent of its total body length.1
Seeleyosaurus lived during the Toarcian age of the Jurassic period, between 184.2 and 182.9 million years ago.3
The first fossil of Seeleyosaurus was found in the Posidonia Shale, a famous rock formation in Germany known for its well-preserved fossils.31
Scientists once thought Seeleyosaurus was a type of Plesiosaurus, but later studies showed it was its own genus.1
Seeleyosaurus had a short neck compared to some other plesiosaurs, with 35 neck vertebrae.3
The species name guilelmiimperatoris means 'of Emperor William', honoring the German emperor.1
Most asked questions about Seeleyosaurus
?How big was Seeleyosaurus?
It was a relatively small plesiosaur, measuring about 2.88 to 3.66 metres (9.4 to 12.0 feet) long and weighing around 199 kilograms (439 pounds).2
?What did Seeleyosaurus eat?
It ate fish and other small sea creatures, catching them with its sharp teeth.2
?Is Seeleyosaurus a dinosaur?
No, it is not a dinosaur. Seeleyosaurus is a plesiosaur, a type of marine reptile that lived in the sea during the Jurassic period.2
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For dino experts
- Scientific name
- Seeleyosaurus
- Named by
- White 19403
- Group
- Plesiosaurs
- Family / clade
- Microcleididae3
- Classification
- Plesiosauria > Sauropterygia3
- Age of the rocks
- 184 to 183 million years (Toarcian)3
- Rock formations
- Posidonia Shale3
- Countries
- Germany3
- Fossil records
- 2 in the Paleobiology Database3
- Discovery
- The first Seeleyosaurus fossil was described by German paleontologist Wilhelm Dames in 1895, who named it Plesiosaurus guilelmiimperatoris. In 1940, American paleontologist Theodore White gave it the new genus name Seeleyosaurus.31
- Still debated
- Scientists still debate whether Seeleyosaurus was a type of elasmosaur or a microcleidid, because different studies place it in different groups.31
Where the facts come from
- THE TAXONOMIC AND PHYLOGENETIC POSITION OF THE PLESIOSAUROIDEA FROM THE LOWER JURASSIC POSIDONIA SHALE OF SOUTH-WEST GERMANY (onlinelibrary.wiley.com)
- Seeleyosaurus (en.wikipedia.org)
- Seeleyosaurus in The Paleobiology Database (CC BY 4.0): age, places, rock formations, classification.
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