Dichotomous Key/Parasitiformes

1

 * Latigynial plates and palpal tarsus
 * Both reduced - 2
 * Neither reduced - 3

2: Ixodida

 * Attachment to host
 * Remain attached for long periods - ../Ixodidae/
 * Do not remain attached long - ../Argasidae/

Could also be the poorly-known Nuttalliellidae

3

 * Diet
 * Scavenger - Holothyrida
 * Other - Mesostigmata