モササウルス

📖 1. 概要

白亜紀末期の海を支配した最上位の海生爬虫類で、現生のオオトカゲやヘビ（有鱗目）の巨大な海の親戚です。

🌐 Wikipedia 要約抜粋

Mosasaurus is the type genus of the Mosasauridae, an extinct group of aquatic squamate reptiles. It lived from about 82 to 66 million years ago during the Campanian and Maastrichtian stages of the Late Cretaceous. The genus was one of the first Mesozoic marine reptiles known to science—the first fossils of Mosasaurus were found as skulls in a chalk quarry near the Dutch city of Maastricht in the late 18th century, and were initially thought to be crocodiles or whales. One skull discovered in 1778 was famously nicknamed the "great animal of Maastricht". In 1808, naturalist Georges Cuvier concluded that it belonged to a giant marine lizard with similarities to monitor lizards but otherwise unlike any known living animal. This concept was revolutionary at the time and helped support the then-developing ideas of extinction. Cuvier did not designate a scientific name for the animal; this was done by William Daniel Conybeare in 1822 when he named it Mosasaurus in reference to its origin in fossil deposits near the Meuse River. The exact affinities of Mosasaurus as a squamate remain controversial, and scientists continue to debate whether its closest living relatives are monitor lizards or snakes.

🦴 2. 体の構造と特徴

上あごの奥（翼状骨）に二列目の歯（翼状骨歯）が生えており、一度くわえた獲物を決して逃しませんでした。

🔍 3. 化石記録と古生態

1764年にオランダのマーストリヒトで発見され、人類に「絶滅」という概念を確立させた歴史的な化石です。

🇰🇷 4. 韓国との関わり

環太平洋における白亜紀の海洋生態系の頂点捕食者です。