Description:
<jats:p>The first ichthyosaur to be recorded from the Pliensbachian Stage of the English Lower Liassic is described as <jats:italic>Leptonectes moorei</jats:italic> sp. nov., extending the geological range of <jats:italic>Leptonectes</jats:italic> to the Pliensbachian. According to criteria for assessing the maturity of ichthyosaurs, it is concluded that <jats:italic>L. moorei</jats:italic> is an immature individual of a relatively small, slender and short snouted species close to the earlier long‐snouted <jats:italic>L. tenuirostris</jats:italic> (Conybeare) which ranges from the Rhaetian to the Sinemurian. The presence of a short‐snouted leptonectid in the Pliensbachian suggests two contrasting patterns of rostral morphology within the clade Leptonectidae in the latest Early Jurassic, rostral reduction within the genus <jats:italic>Leptonectes</jats:italic> and rostral elongation in <jats:italic>Excalibosaurus</jats:italic><jats:italic>Eurhinosaurus</jats:italic>.</jats:p>