ワニ類は恐竜とは異なる戦略で白亜紀末の大量絶滅を乗り越えて生命のリレーを続けた

現生のワニ類は熱帯から亜熱帯地方に23種が分布している。約２億２千万年前のワニ形類は２足歩行の食虫性の動物であったが、このグループから進化したワニ類はほぼ全てが半水生生活に適応していた。ジュラ紀になると海での生活に適応するものも現れた。ワニ類の驚くべき進化の歴史はこの保守的な戦略によるところが大きい。

At the end of the Cretaceous while dinosaurs were on the brink of extinction, crocodiles survived and took over dinosaurs thanks to the different adaptation strategy they adopted during their early evolution.

Even though 23 species of crocodiles are distributed nowadays all around the world between tropical and subtropical regions, modern crocodiles are very different from their early ancestors. Indeed, about 220 million years ago, Crocodylomorph were bipedal insectivorous animals whose descendants evolved and adapted to the semi-aquatic life as we know today. At the beginning of the Jurassic, some of them even adapted to the marine life. This amazing evolution path is due for a big part to this conservative strategy.