Question

Which one is an example of a living fossil?
A. Coral
B. Ascidia
C. Octopus
D. King crab

Answer 1

Living fossil is a group of organisms that are the last remaining species which closely resembles organisms otherwise known only from the fossil record

Complete answer:
A living fossil is an existing species that closely resembles an organism otherwise known only
from the fossil record. Among the given options, king crab is the only chelicerates that have
compound eyes and is the only living representative of the Merostomata Chelicerates. (Chelicerata) are a group of arthropods that includes many organisms like harvestmen, scorpions, mites, spiders, horseshoe crabs, sea spiders, and ticks. There are about 77,000 living species of chelicerates. Chelicerates have two body segments (tagmenta) and six
pairs of appendages. They have an exoskeleton that is rich in chitin. Another characteristic
a feature of this group is the presence of fine hair over the body which acts as sensory receptors which can detect slight movements in the air .Merostomata is the scientific name of the horseshoe crab. It is alSo, the common name of four species of marine arthropods found on the east coasts of Asia and of North America. Despite their name, horse-shoe crabs are not crabs at all but are related to scorpions, spiders, and some extinct trilobites.

Therefore, Option D, King crab is correct.

Note:
-Cycads are gymnosperms that are living fossils
-Solenodon is a living fossil found on the Caribbean islands of Hispaniola and Cuba. They are
small and clumsy and fully colored; they are one of the rarest and weirdest mammals on the
planet. The solenodon is one of the very few mammals to produce its own venom, which flows up through grooves in the incisors in its bottom jaw.
-The chevrotain also known as the mouse-deer is another living fossil and is mostly found in
southeast Asia.