During the mesozoic period, diapsids diverged
pterosaurs and dinosaurs
mammals and reptiles
lepidosaurs and archosaurs
testudines and sphenodontia

lepidosaurs and archosaurs

Explanation:

Diapsids was a group of terrestrial vertebrates that are the ancestors of lizards, tuatuaras, crocodiles and birds. In the prehistory. The diapsids were a group that included dinosaurs, pterosaurs, plesiosaurs, notosaurs, kinosaurs, prolacertiformes, and aetosaurs. During the Mesozoic period, the diapsids diverged into lepidosaurs and arcosaurs.

The Lepidosaurs gave rise to one of Reptilia's largest groups, containing more than 4,000 lizard species and 2,700 snake species, in addition to the two tuataras species. They are predominantly terrestrial tetrapods, with some secondary aquatic species, especially among snakes.

Archosaurs, also known as Avesuchia, are a group of reptiles that stand out from the rest for their current and past importance. It is a group that emerged at the beginning of the Mesozoic Era (Middle Triassic - ca. 235 million years ago) and quickly spread to the various continents, where they became the dominant vertebrates. Currently this group is represented by crocodilians (alligators, crocodiles and gavials) and birds. In the past, however, arcosaurs were more diverse and, in addition to crocodilians and birds, were represented by pterosaurs (flying reptiles), various forms of non-avian dinosaurs, and other lesser-known groups.

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