ベーリング島
Steller's sea cows are reported to have grown to long as adults, much larger than extant sirenians. In 1987, a rather complete skeleton was found on Bering Island measuring . In 2017, another such skeleton was found on Bering Island measuring , and in life probably about . Georg Steller's writings contain two contradictory estimates of weight: . The true value is estimated to fall between these figures, at about . This size made the sea cow one of the largest mammals of the Holocene epoch, along with whales, and was likely an adaptation to reduce its surface-area to volume ratio and conserve heat.