Mollistephaninae and Frebolditinae, new subfamilies of Middle Jurassic stephanoceratid Ammonoidea

Abstract

Two new Bajocian stephanoceratid subfamilies are distinguished based on morpho-structural criteria and phyletic patterns. At the Aalenian/Bajocian transition,

Pseudoteloceras, a new stephanoceratid genus (Ammonitida) of the lower Humphriesianum Zone (lower Bajocian, Middle Jurassic) from western Tethys

“…(2) The thin Bajocian successions of the sector south of Caen (Calvados, NW France) where the condensed sections of the ''Oolithe ferrugineuse de Bayeux'' Formation (Rioult et al, 1991, and references therein) are reduced by recurrent discontinuities and the fossils are commonly preserved as reelaborated elements (i.e. exhumed and displaced before their final burial: Fernandez-Lopez, 1991, 1995, 2007, 2011Fernandez-Lopez & Pavia, 2015). The specimens come from outcrops of Feuguerolles-sur-Orne, Bretteville-sur-Odon, Evrecy, Maizet and Les Fours à Chaux at Croisilles (Fig.…”

“…The biostratigraphical and biochronostratigraphical classifications and units proposed by Rioult et al (1997) are referred to herein as they are accepted almost unanimously (see Sandoval et al, 2001Sandoval et al, , 2002Callomon, 2003;Fernandez-Lopez and Pavia, 2015, and references therein). The ammonite Standard Zonation, dividing the Bajocian Stage of the Mediterranean-Caucasian Subrealm, is as follows from bottom up: lower Bajocian: Discites Zone, Laeviuscula Zone, Propinquans Zone (Patella, Hebridica subzones), Humphriesianum Zone (Romani, Umbilicum, Blagdeni subzones); upper Bajocian: Niortense Zone, Garantiana Zone, Parkinsoni Zone.…”

“…The pandemic family Stephanoceratidae Neumayr, 1875, one of the five families of the Middle to Late Jurassic superfamily Stephanoceratoidea Neumayr, 1875, evolves from the Otoitidae Mascke, 1907, at the Aalenian/Bajocian transition (Fernandez-Lopez, 2014;Fernandez-Lopez and Pavia, 2015) and ranges throughout the Bajocian and Bathonian. It consists of three classical subfamilies Stephanoceratinae Neumayr, 1875, Garantianinae Wetzel, 1937, and Cadomitinae Westermann, 1956, and in addition two new early Bajocian subfamilies were recently defined: Mollistephaninae Fernandez-Lopez and Frebolditinae Fernandez-Lopez andPavia, 2015 (for diagnostic features see Fernandez-Lopez and Pavia, 2015, p. 2, and references therein).…”

“…136, figs. 4-5, neotype designed by Westermann, 1954, p. 338, on de Grossouvre, 1930, from the upper Bajocian of Calvados, France) span from the uppermost lower Bajocian Humphriesianum Zone to the upper Bathonian/lower Callovian transition (Sandoval, 1983;Fernandez-Lopez, 1985;Dietl and Herold, 1986;Fernandez-Lopez and Pavia, 2015). The genus Lokuticeras Galá cz, 1994 (type-species Lokuticeras rossbrunnense Galá cz, 1994, p. 165, pl.…”

Ups and downs of belemnite diversity in the Early Jurassic of Western Tethys

“…2010; Joly 2012; Sandoval et al . 2012; Fernandez‐Lopez & Pavia 2015; for brachiopods see Manceñido 2002; Debahuti 2010; for bivalves see Damborenea 2000;Aberhan 2001; for corals see Leinfelder et al . 2002; for ostracods see Boomer & Ballent 1996; Guzel 2012; Ballent & Whatley 2012; and for marine reptiles see Gasparini et al .…”