A combination of methods from cladistics and stratophenetic analyses is used for a reconstruction of Early and
    Middle Devonian ammonoid phylogeny.  The analyses are based mainly on principal characters such as conch geo-
    metry (coiling form, whorl expansion rate, whorl cross-section shape), septal geometry (form of septa, number, posi-
    tion, and shapes of lobes), and ornament (growth lines und ribs); a new classification scheme of the ancient
    ammonoid order Agoniatitida is proposed.  It is subdivided into four suborders: Agoniatitina (paraphyletic),
    Gephuroceratina (monophyletic), Anarcestina (paraphyletic), and Pharciceratina (monophyletic).  Morphometric
    analysis shows the unfolding of several morphological trends, such as the modification of coiling parmeters, among
    the Early md Middle Devonian ammonoids.  Two major independent lineages can be recognised in the phylogeny of
    the Middle Devonian ammonoids, the first represents the agoniatids in which the Gephuroceratina is nested, the sec-
    ond are the anarcistids which gave rise to the Pharciceratina.  The new families Latanarcestidae, Tamaritidae,
    Atlantoceratidae, und Taouzitidae, as well as the new genera Taouzites, Croyites and Meragoniatites are introduced.