There is a possible age difference of perhaps over thirty million years between the Berriasian-Valanginian British and the younger Albian-Cenomanian American form.
In addition to its late Jurassic occurrence, Aegirosaurus has recently been discovered from the late Valanginian (Early Cretaceous) of Southeastern France (Laux-Montaux, department of Drôme; Vocontian Basin), the first diagnostic ichthyosaur recorded from the Valanginian.
Nqwebasaurus (pronounced: nnkweb-ah-sawr-us; in fact, "nq" is a nasal postalveolar click ŋǃ) is the name given to a genus of dinosaur sometime between the Tithonian to Valanginian (Late Jurassic to Early Cretaceous).
The holotype, BMNH R2559 (incorrectly given by Owen as BMNH R2556), was found near Cuckfield in layers of the Tunbridge Wells Sand Formation dating from the late Valanginian.