Diversity

 Diversity

Size

Further information: Largest organisms and Smallest organisms

The blue whale (Balaenoptera musculus) is the largest animal that has ever lived, weighing up to 190 tonnes and measuring up to 33.6 metres (110 ft) long.^[62][63] The largest extant terrestrial animal is the African bush elephant (Loxodonta africana), weighing up to 12.25 tonnes^[62] and measuring up to 10.67 metres (35.0 ft) long.^[62] The largest terrestrial animals that ever lived were titanosaur sauropod dinosaurs such as Argentinosaurus, which may have weighed as much as 73 tonnes, and Supersaurus which may have reached 39 metres.^[64][65] Several animals are microscopic; some Myxozoa (obligate parasites within the Cnidaria) never grow larger than 20 μm,^[66] and one of the smallest species (Myxobolus shekel) is no more than 8.5 μm when fully grown.^[67]

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  The blue whale is the largest animal that has ever lived; it can be up to 33.6 metres (110 ft) long.
 
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  Myxozoans such as Myxobolus cerebralis are single-celled parasites, never more than 20 μm across.