CollectA HydrotherosaurusCollectA Hydrotherosaurus CollectA Model 88139 Age: 3 years and up Product Dimensions: 19 x 6. 5 x 6 cm Hydrotherosaurus, a type of marine reptile known as a plesiosaur, was an awe inspiring creature that roamed the oceans during the Late Cretaceous period. Its most notable feature was its incredibly long neck, which consisted of around 60 vertebrae, making it one of the longest necked plesiosaurs ever discovered. With such a neck, Hydrotherosaurus