Almost 4 whorls of the very strongly ribbed shell are well shown. This liparoceratid intermediate possibly gave rise to the serpenticone Aegoceras , which its inner whorls resemble, with close strong ribbing, some forming ventral chevrons (which are absent in this single-sided specimen). The outer whorls are also quite similar to Liparoceras (PLI 7.0A & APA 2.0) giving these specimens a paedomorphic phylogeny. This is also closely related to the genus Pleuroceras. From England, UK.
Size: 55 mm in diameter
Size: 55 mm in diameter