Heteromorph ammonites from the Tata Limestone Formation (Aptian–Lower Albian), Hungary

Abstract

ABSTRACT. An important new ammonite fauna was collected by Fu Èlo Èp in 1953 and 1960 from basal lenses between a Tithonian hardground and the overlying Tata Limestone Formation containing many heteromorph ammonites. This assemblage of ammonites has been determined as being of Early Albian (tardefurcata Zone) age. Among the heteromorphs are species of Tonohamites and Ptychoceras, which are familiar components of Late Aptian or Early Albian ammonite faunas. The genera Ephamulina, Hamites and Protanisoceras are also recorded, the earliest species of which had previously come from sediments of late Early Albian (mammillatum Zone) age. While Hamites and Protanisoceras are common in Europe, Ephamulina had previously only been known from Madagascar. The discovery of Ephamulina, Hamites and Protanisoceras supports the view that these phylogenetically signi®cant ammonites had radiated close to the Aptian/Albian boundary. Four new species of Hamites (H. czaszari, H. fazekasensis, H. fueloepi and H. kalvariensis) and one new species of Tonohamites (T. boldii ) are described.

First occurrence of Pictetia (Ammonoidea) from the Albian of Japan and its systematical implications

“…Most of the younger members of the Anisoceratidae show bifid lobes but trifid lobes occur in the older members. A similar suture line configuration with trifid lobes is present in the closely related Lower Albian paraphyletic Hamitidae (Monks 1999, Monks 2002, Szives & Monks 2002. Based on the ontogenetic changes from juvenile trifid lobes to later ontogenetic stages with subsymmetric bifid lobes, Pictetia obviously belongs to one of these two groups.…”

“…That idea is mainly based on the suture line development concerning the low number of elements becoming more or less strongly slit during ontogeny. Nevertheless, both the Ancylocerataceae, with predominantly trifid lobes, and the Ancyloceratina are recognized as a paraphylum (Szives & Monks 2002).…”

“…later assigned to Ephamulina, a genus belonging to the Anisoceratidae (Collignon 1963, Kennedy et al 2000, Szives & Monks 2002, Szives et al 2007.…”

Albian and Cenomanian ammonites of the eastern margin of the Lut block (East Iran)

“…Dimensions ( Occurrence: This species occurs in upper Albian strata of Hungary (SZIVES et al, 2007) and the lower and middle lower Cenomanian of southern England (C.W. WRIGHT & E.V.…”

Cladistic Analysis of A Problematic Ammonite Group: the Hamitidae (Cretaceous, Albian–turonian) and Proposals for New Cladistic Terms

“…One of these is Hamites pseudattenuatus Casey, 1961 from the Lower Albian (Douvilleiceras mammillatum Zone, Sonneratia kitchini Subzone) of Norfolk, England. The second is a species of Hamites from the Tata Limestone Formation (Middle Aptian±Lower Albian) recorded by Szives (1996Szives ( , 1999 but as yet not described (Text-®g. 3A).…”