Article: The affinities of Idiohamites ellipticoides Spath (Cretaceous Ammonoidea)

Idiohamites ellipticoides Spath is an aberrant species of the genus Idiohamites which shows the recoiling trend so widespread in Cretaceous heteromorph ammonites. Its ornament is identical with some members of the largely southern hemisphere family Labeceratidae, but study of suture lines show this to be merely a case of homeomorphy. The species is described and illustrated on the basis of large new collections.