Name: Helveticosaurus
Phonetic: Hel-vet-e-co-sore-us.
Named By: Peyer‭ ‬-‭ ‬1955.
Classification: Chordata,‭ ‬Reptilia,‭ ‬Sauropsida,‭ ‬Diapsida,‭ ‬Archosauromorpha‭?
Species: H.‭ ‬zollingeri‭ (‬type‭)‬.
Diet: Probably shellfish.
Size: Uncertain.
Known locations: Europe,‭ ‬Switzerland.
Time period: Anisian of the Triassic.
Fossil representation: Almost complete remains.

       For a long time Helveticosaurus was thought to be one of the placodonts,‭ ‬specialist marine reptiles that lived in the Triassic seas‭ ‬that fed upon shellfish.‭ ‬However further analysis has revealed that only the vertebra of Helveticosaurus are similar to the placodonts,‭ ‬which has led to Helveticosaurus being re-classed as a diapsid‭ (‬two holes in the back of the skull,‭ ‬similar to lizards‭) ‬and possibly an archosaur,‭ ‬reptiles that were the dominant land animals of the Triassic before the advent of the large dinosaurs.
       Helveticosaurus however was adapted for an aquatic life,‭ ‬although with a body similar to the early unarmoured placodonts such as Paraplacodus and Placodus,‭ ‬it may not have spent all of its time in the water.‭ ‬Also like with these placodonts,‭ ‬Helveticosaurus is thought to have primarily swum with a laterally undulating‭ (‬side to side‭) ‬movement of the tail while using its legs to steer and change direction by pushing in the opposite direction that it wanted to turn.‭ ‬Perhaps the best examples of this style of swimming observable today are newts and marine iguanas.
       The skull of Helveticosaurus was quite robust with short jaws,‭ ‬something that has caused confusion amongst some people as to why they would not be along the same proportions as other marine reptiles such as nothosaurs and pliosaurs,‭ ‬especially so when you consider that Helveticosaurus had caniform teeth.‭ ‬Usually however such an adaptation is seen in predators‭ ‬that need to focus bite force so that they can bite through hard and tough prey.‭ ‬This is a simple principal where the closer to the fulcrum‭ (‬in an animal the point of jaw articulation‭) ‬an object is,‭ ‬the greater the crushing force it is exposed to.‭ ‬This would see Helveticosaurus being capable of crushing the protective armour of shellfish like bivalves and crustaceans that would have thwarted predators with less powerful jaws.‭ ‬These kinds of prey would have also been the most suitable for Helveticosaurus as its swimming style meant that it was probably incapable of chasing after faster prey like fish.‭

Further reading
- Die Triasfauna der Tessiner Kalkalpen. XVIII. Helveticosaurus zollingeri, n.g. n.sp. - Schweizerische Paläontologische Abhandlungen. 72: 3–50. - Bernhard Peyer - 1955.


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