Loricata is a clade within the Archosauria that includes the last common ancestor of all living crocodilians and all of its descendants. It is considered a crown group of the Crocodylomorpha. The name "Loricata" is derived from the Latin word lorica, meaning a cuirass or coat of mail, referring to the armored scutes (osteoderms) characteristic of these reptiles.
Classification
Historically, Loricata was sometimes used as an order, encompassing all crocodilians. In modern phylogenetics, Loricata is typically recognized as a superorder or a crown group, with its sole living order being Crocodilia (or Crocodylia). The group diverged from other archosaurs during the Triassic period.
Characteristics
Members of Loricata are distinguished by several key features:
- Osteoderms: The most prominent feature is the presence of rows of bony plates (osteoderms) embedded in the skin, forming a protective armor, particularly along the dorsal surface.
- Semi-aquatic Lifestyle: All extant Loricata are semi-aquatic predators, inhabiting tropical and subtropical regions around the world. They are highly adapted to both aquatic and terrestrial environments.
- Strong Jaws: They possess powerful jaws lined with numerous conical teeth, used for seizing prey.
- Valvular Nostrils and Ears: Specialized valves allow them to close their nostrils and ear openings when submerged, preventing water entry.
- Four-Chambered Heart: Unlike most reptiles, Loricata have a fully four-chambered heart, similar to birds and mammals, which is an advanced circulatory adaptation.
Genera
The extant members of Loricata belong to three families within the order Crocodilia:
- Alligatoridae: Includes alligators and caimans.
- Crocodylidae: Includes true crocodiles.
- Gavialidae: Includes gharials and false gharials.
Numerous extinct forms are also classified within Loricata, providing insights into the evolutionary history of crocodilians.