thalattosuchian

Thalattosuchian is an extinct group of marine crocodylomorphs that lived during the Jurassic and Early Cretaceous periods. These reptiles were adapted for a life in the ocean, with some species evolving streamlined bodies, flippers, and tails that were likely used for propulsion. Unlike their modern, land-dwelling relatives, thalattosuchians had significantly reduced limbs, making them less suited for terrestrial locomotion.

The group is divided into two main families: the Thallatocheiridae and the Metriorhynchidae. Thallatocheiridae, such as Thallatocherius, were generally smaller and more generalized in their adaptations. The Metriorhynchidae, a more diverse and widespread family, included larger and more specialized forms like Metriorhynchus and Geosaurus. These animals possessed various skull shapes, ranging from slender and elongated to more robust, suggesting diverse feeding strategies.

Fossil evidence for thalattosuchians has been found in marine deposits across the globe, including Europe, North America, and Africa. Their presence in these environments indicates a successful colonization of marine ecosystems during the Mesozoic Era. The exact reasons for their extinction are not fully understood, but they likely succumbed to environmental changes or competition with other marine predators that emerged during the Cretaceous. Their evolutionary lineage highlights the adaptability of the crocodylomorph body plan to aquatic environments.