1 · Observe

Microscopy records structures such as spines, mouthparts and specialized limbs.

2 · Compare

Seven coastal species are examined together: five redescribed and two newly named.

3 · Cross-check

Molecular phylogeny tests whether genetic patterns support distinctions suggested by anatomy.

4 · Make repeatable

A dichotomous key turns distinctions into paired choices another observer can test.

Callipallene pilosuspedes

Recorded: Long, curved lower-leg spines; grooming with comb-bearing ovigers.
Still unknown: How its traits vary across sexes, ages and locations.

Tanystylum kiixin

Recorded: Close association with the hydroid Plumularia setacea; smaller, less dexterous egg-carrying limbs.
Still unknown: The broader consequences of its observed debris and parasite load.

The limiting branch: only one C. pilosuspedes specimen is known. Its features can be documented, but one animal cannot reveal the species’ normal range of variation.