Key Points of Morphological Differentiation of Nautiloids and Helicoceramites
In view of the challenges in identifying aquatic animals such as Nautilidae,Eutrephoceras and Helicoceramites,this paper summarizes key identification points employed by customs laboratories,including external morphology,growth lines,reddish-brown radial markings,sutures and umbilical features.The identification of extant Nautilidae mainly relies on differences in peristoma,size,umbilical part,reddish-brown radial markings and growth lines.Eutrephoceras and Helicoceramites fossils are identified based on the differences in shell,peristoma,suture line,umbilical part,growth lines,septum and drawing line.This research can provide valuable reference for practitioners involved in the identification process.
NautiloidsHelicoceramitesmorphological identificationendangered speciesawareness of aquatic animal protection