Here's a list of the seven longest extinct and extant animal species.

This article presents the longest animals to have ever existed or still existing on the planet. This list of longest animals refers to their over-all length not the weight or height.

Here are the longest extant animals in the world…

1.) Bootlace Worm (Lineus longissimus)


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The longest known animal in the world is the Bootlace Worm. Although this creature usually has only a 5-10 mm in width, it can grow enormously as long as 60 meters. It can be found along the coasts of Britain. The longest specimen on record which was measured in Scotland in 1864 had a length of 55 meters.

2.) Lion's Mane Jellyfish (Cyanea capillata)


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The second longest living animal on the planet is the Lion's Mane Jellyfish. It is also the largest known species of jellyfish. They inhabit the cold waters of Arctic, Atlantic and Pacific Oceans. The largest specimen on record was found washed up on the shore of Massachusetts Bay in 1870. Its tentacles were 36.5 meters long and its bell (body) had a diameter of 2.3 meters.

3.) Blue Whale (Balaenoptera musculus)

blue whale

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Although the Blue Whale is considered as the largest animal ever known to have existed, it is only the 3rd longest animal in term of length. This enormously huge marine mammal can grow as long as 33.6 meters and can weigh as much as 180 metric tons.

Here are the longest extinct animals in the world…

1.) Amphicoelias fragillimus


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Some experts said that the Amphicoelias fragillimus is the longest and largest animal to have existed on Earth. Its length ranged from 40 meters to 60 meters and weighed as much as 122 metric tons. But due to lack of complete fossils of this creature, the data provided can not be considered factual. Other scientists estimated that this species could have measured about 58 meters long.

2.) Diplodocus hallorum


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The Diplodocus hallorum of North America was an extremely long animal with very large and long-neck and very long tail. Estimated length of this extinct animal ranged from 40 to 50 meters long and can grow as long as 54 meters making it the longest known dinosaur. It was estimated that it can weigh as much as 113 tonnes. This species is the longest dinosaur known from a complete skeleton.

3.) Bruhathkayosaurus

Another very long extinct creature is the Bruhathkayosaurus. This creature, which is among the longest and largest animals to have existed, is estimated to have a length of up to 45 meters and a weight that ranged from 140 to 220 metric tons.

4.) Silver Lizard – Argentinosaurus


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Argentinosaurus of South America is one of the largest or heaviest dinosaurs to have existed. It is also one of the longest animals to ever walk on the planet. This extinct creature is believed to have existed more than 90 million years ago. This very huge animal's length is estimated from 30 to 35 meters long and can way as much as 110 short tons.