Ichthyosaur

Ichthyosaurs (Greek for "fish lizard" - ιχθυς or ichthys meaning "fish" and σαυρος or sauros meaning "lizard") are large marine reptiles. Ichthyosaurs belong to the order known as Ichthyosauria or Ichthyopterygia ('fish flippers' - a designation introduced by Sir Richard Owen in 1840, although the term is now used more for the parent clade of the Ichthyosauria).

Ichthyosaurs thrived during much of the Mesozoic era; based on fossil evidence, they first appeared approximately 250 million years ago (mya) and at least one species survived until about 90 million years ago, into the Late Cretaceous. During the early Triassic Period, ichthyosaurs evolved from a group of unidentified land reptiles that returned to the sea, in a development parallel to that of the ancestors of modern-day dolphins and whales, which they gradually came to resemble in a case of convergent evolution. They were particularly abundant in the later Triassic and early Jurassic Period, until they were replaced as the top aquatic predators by another marine reptilian group, the Plesiosauria, in the later Jurassic and Cretaceous Period. In the Late Cretaceous, ichthyosaurs became extinct for unknown reasons.

Half-Life (series)

Half-Life (stylized HλLF-LIFE) is a series of first-person shooter video games that share a single science fiction alternate history. The games in the series all utilize either the GoldSrc or Source engines and are linear, narrative, single-player titles.

Valve Corporation is the developer, and partly the publisher and distributor, for their signature games of the series. The major titles in the series feature the player as the protagonist, Gordon Freeman, a theoretical physicist initially employed by the Black Mesa Research Facility. Two of these games, Half-Life and Half-Life 2 are full length titles, while two more, Half-Life 2: Episode One and Half-Life 2: Episode Two, are shorter, episodic titles. A final episode, Half-Life 2: Episode Three, was originally scheduled to appear around Christmas 2007, but now has no public release date.

A puzzle-based first-person series, set in the same fictional universe as the Half-Life games, was created with Portal in 2007, followed by a sequel, Portal 2, in 2011.