Extant

In biology, an extant group is one which has survived to the present day, and so it is a living group. This distinguishes it from an extinct group.

The term 'extant' can also be used to describe species or higher groups (such as genera or families) which are still in existence (living).Barnes, Robert D. 1982. Invertebrate zoology. Holt-Saunders, Philadelphia PA. pp945–946 

Example: in the group of molluscs known as the cephalopods, there are about 600 extant species and 7500 extinct species.
http://www.iucn.org/themes/ssc/red_list_2004/GSAexecsumm_EN.htm  .

 References 

Category:Biology