All live in the fresh waters of South America and have a single row of sharp, interlocking teeth on each jaw.

它们都生活在南美洲的淡水中，每个下巴上都有一排锋利的、互锁的牙齿。

A new study reports that the planthopper Issus coleoptratus evolved a foolproof solution to this problem: in young nymphs of the species, the two legs meet under the belly in plates fringed with interlocking teeth.

它们在幼年时期，它们的两条腿在肚子下方被有紧连着的牙齿的鳞甲连接。

Bivalve shells are made to open and shut, but on what a number of patterns is the hinge constructed, from the long row of neatly interlocking teeth in a Nucula to the simple ligament of a Mussel!

双壳贝壳是用来打开和关闭的， 但是铰链的构造有多少种模式， 从 Nucula 的一长排整齐互锁的牙齿到贻贝的简单韧带！