The typical nemertean body is very thin in proportion to its length. The smallest are a few millimeters long, most are less than , and several exceed . The longest animal ever found, at long, may be a specimen of Lineus longissimus, Ruppert, Fox and Barnes refer to a Lineus longissimus long, washed ashore after a storm off St Andrews in Scotland. Other estimates are about . Zoologists find it extremely difficult to measure this species. For comparison: The longest recorded blue whale was . The dinosaurs Argentinosaurus and Patagotitan are estimated at approximately and respectively. A specimen of the Arctic giant jellyfish Cyanea capillata arctica was long.
The typical nemertean body is very thin in proportion to its length. The smallest are a few millimeters long, most are less than , and several exceed . The longest animal ever found, at long, may be a specimen of Lineus longissimus, Ruppert, Fox and Barnes refer to a Lineus longissimus long, washed ashore after a storm off St Andrews in Scotland. Other estimates are about . Zoologists find it extremely difficult to measure this species For comparison: The longest recorded blue whale was . The dinosaurs Argentinosaurus and Patagotitan are estimated at approximately and respectively. A specimen of the Arctic giant jellyfish Cyanea capillata arctica was long.