| Identification and utilization of proxy characters in extant families has been accomplished with success for fossil members of the Calappidae, Hepatidae, Necrocarcinidae, Matutidae, and Hexapodidae. The fossil and extant Raninidae have been revised using primarily hard-part morphology preserved in the fossil record although formal designation of “proxy characters” has not occurred. Hard-part characters can also be used to differentiate among members of the Atelecyclidae and the Cheiragonidae. Thus, the method of using proxy characters is demonstrably suitable for application to a difficult group like the Xanthoidea. |
