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Thecodontian, archaic term formerly applied to any member of a group of primitive archosaurs (“ruling reptiles”) thought to include the ancestral stock of all other archosaurs, including birds, dinosaurs, pterosaurs (extinct flying reptiles), and crocodiles. The name thecodont means “socket-toothed.”
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dinosaur: Dinosaur ancestors…group of Triassic reptiles termed thecodontians (“socket-toothed reptiles”). Today it is recognized that “thecodontian” is simply a name for the basal, or most primitive, members of the archosaurs (“ruling reptiles”), a group that is distinguished by the three anatomic features mentioned above and that includes dinosaurs, pterosaurs (flying reptiles), crocodiles,…
reptile: Annotated classificationTeeth in deep sockets (thecodont); nasal longer than frontal; no pineal foramen on skull roof; hooked metatarsal. †Order Pterosauria (pterodactyls) Upper Triassic to Upper Cretaceous. Two suborders, about 16 families, and more than 30 genera. Highly specialized flying reptiles with hollow bones; fourth digit of the forelimb greatly elongated…
Triassic Period: The first dinosaurs…in the Early Triassic, the thecodonts became common during the Middle Triassic but disappeared before the beginning of the Jurassic. Typical of this group of archosaurs (or “ruling reptiles”) in the Triassic were small bipedal forms belonging to the pseudosuchians. Forms such as
Lagosuchuswere swift-running predators that had erect…