Mark Carwardine's ATA GLANCE...

摘要

The word 'ivory' usually refers to the tusks (enlarged upper incisors) of elephants and extinct mammoths and mastodons. Tusks are found in almost all African elephants (they are much larger in males - the record is 3.5m long) and some male Asian elephants. However, 'ivory" can correctly be used to describe any mammalian tooth - such as from hippos, walruses, narwhals and sperm whales - which is large enough to be carved or engraved.