Question

Which of the following is considered as a living fossil?

• A. Protopterus
• B. Coelacanth
• C. Ornithorhynchus
• D. Peripatus

Answer 1

The correct option is B Coelacanth

The term living fossils refers to organisms which belong to an extant taxa (taxonomic group with living members) that have resemblance in appearance to ancestral species about which we know only from fossil records.

The coelacanths are members of the genus Latimeria which comes under a rare order of fishes known as Coelacanthiformes. The earliest fossils of coelacanths were discovered in the 19th century and were seen to be more closely related to tetrapods (four legged vertebrates) than to the ray-finned fishes (connecting links). In 1938, the first living Latimeria specimen was discovered. Its discovery after it was presumed to have been extinct for millions of years, made coelacanths well known examples of an evolutionary line that had disappeared from the fossil record history, only to make an appearance again after millions of years. Coelacanths are considered to be living fossils because scientists believe them to be the sole remaining member of a taxonomic group about which we know only from fossil records, with no close relations alive.


Protopterus (lungfish), Ornithorhynchus and Peripatus are examples of connecting links (living organisms which possess the characteristics of two different evolutionary groups and form a connecting link between them). Protopterus is a connecting link between fishes and amphibians. Ornithorhynchus (duck-billed platypus) is a living egg-laying mammal which is believed to be the connecting link between reptiles and mammals. Peripatus is an invertebrate terrestrial worm that is considered as a connecting link between annelids (segmented worms) and arthropods (jointed leg organisms).