Final answer:
The Late Triassic saw the diversification of reptiles, including dinosaurs, but it was not the time when amphibians and bats first appeared. Amphibians thrived much earlier, around 300 million years ago, and bats appeared in the fossil record around 52.5 million years ago, well after the Triassic period.
Step-by-step explanation:
The groups of animals that first appeared during the Late Triassic were not amphibians and bats. The heyday of amphibians was around 300 million years ago, specifically in the Carboniferous period, which is often termed the "age of the amphibians" due to their diversity and abundance. By the Triassic period, however, amphibians' dominance had diminished, making way for the reptiles, including the earliest dinosaurs.
During the Triassic, the mass extinction paved the way for the rise of dinosaurs in the Jurassic, often considered the golden age of dinosaurs. The earliest birds evolved from reptile ancestors during this time. The therapsids, a group that eventually gave rise to mammals, had developed distinct mammalian traits by the Triassic. However, bats, being mammals, did not appear until much later in the timeline, with the earliest known bat fossils dating to around 52.5 million years ago, long after the Triassic period.
Regarding other significant evolutionary developments, the Permian period saw the rise of the therapsids, which would evolve into mammals, while cynodonts, a successful group of therapsids, thrived during the Triassic. Both therapsids and cynodonts exhibited mammalian characteristics, but it's crucial to note that modern mammalian groups, including bats, did not emerge until much later.