Ordovician-Silurian Extinction Event (444 million years ago):
- Graptolites: These were colonial, floating animals that were common in ancient oceans.
- Trilobites: These were diverse marine arthropods that occupied various ecological niches.
- Brachiopods: These were marine invertebrates with bivalve shells, similar to modern clams.
Late Devonian Extinction Event (374 million years ago):
- Placoderms: These were the first jawed fishes and included armored species like Dunkleosteus.
- Acanthodians: These were spiny-finned fishes that were diverse in Devonian ecosystems.
- Ammonoids: These were shelled cephalopods, closely related to modern-day nautilus.
Permian-Triassic Extinction Event (252 million years ago):
- Trilobites: The last remaining trilobite species disappeared during this extinction event.
- Synapsids: Many non-mammalian synapsids, the ancestors of mammals, went extinct.
- Conodonts: These small, eel-like animals had tooth-like structures and were essential components of ancient food webs.
Triassic-Jurassic Extinction Event (201 million years ago):
- Dinosaurs: Many non-avian dinosaurs, including sauropods, theropods, and ornithischians, became extinct.
- Marine reptiles: Groups such as ichthyosaurs, plesiosaurs, and many marine crocodile lineages also went extinct.
- Conodonts: The remaining conodont species disappeared during this event.
Cretaceous-Paleogene Extinction Event (66 million years ago):
- Non-avian dinosaurs: All remaining non-avian dinosaurs, except for the ancestors of modern birds, became extinct.
- Marine reptiles: Various groups of marine reptiles, such as mosasaurs, plesiosaurs, and many marine turtles, also went extinct.
- Ammonoids: The last remaining ammonoid species vanished during this event.
- Many mammal, bird, and plant species also became extinct during these mass extinction events, leading to significant ecological changes and paving the way for the rise of new dominant species.