Which sentence contains a comma splice? The last known Tasmanian tiger, nicknamed Benjamin, died in a zoo in 1936; the species was declared extinct after 50 years passed with no further sightings.

To save the California condor, scientists trapped the surviving 27 birds and bred them in captivity, but the condor is still one of the rarest birds in the world.

Birds are the direct descendants of a type of small, feathered dinosaur, that means the dinosaurs are still alive!

Some scientists want to clone woolly mammoths, yet others worry that bringing an extinct species back from the dead could trigger an ecological disaster.