During the first half of the nineteenth century, the number of plesiosaur finds steadily increased, especially through discoveries in the sea cliffs of Lyme Regis. Sir Richard Owen alone named nearly a hundred new species. The majority of their descriptions were, however, based on isolated bones, without sufficient diagnosis to be able to distinguish them from the other species that had previously been described. Many of the new species described at this time have subsequently been invalidated. The genus "Plesiosaurus" is particularly problematic, as the majority of the new species were placed in it so that it became a wastebasket taxon. Gradually, other genera were named. Hawkins had already created new genera, though these are no longer seen as valid. In 1841, Owen named "Pliosaurus brachydeirus". Its etymology referred to the earlier "Plesiosaurus dolichodeirus" as it is derived from πλεῖος, "pleios", "more fully", reflecting that according to Owen it was closer to the Sauria than "Plesiosaurus". Its specific name means "with a short neck". Later, the Pliosauridae were recognised as having a morphology fundamentally different from the plesiosaurids. The family Plesiosauridae had already been coined by John Edward Gray in 1825. In 1835, Henri Marie Ducrotay de Blainville named the order Plesiosauria itself.