Late CenomanianeEarly Turonian ammonites of the southern Tethys margin from Morocco to Oman: Biostratigraphy, paleobiogeography and morphology Christian Meister * , André Piuz Natural History Museum of Geneva, Geology and Paleontology Department, CP 6434,1211 Geneva 6, Switzerland article info Article history: Received 28 November 2012 Accepted in revised form 29 March 2013 Available online xxx Keywords: Ammonites Late Cretaceous Southern Tethys margin Biostratigraphy Paleobiogeography Morphology abstract The CenomanianeTuronian ammonite biostratigraphical framework for the southern Tethys margin (North Africa, Middle East and the Arabian Peninsula) is becoming better understood. A first attempt at a synthetic range chart is presented, with 85 taxa and precise correlations for ammonites along a weste east transect from Morocco to Oman, inclusive of the Trans-Saharan Seaway as far south as northern Nigeria. On the basis of a critical review of ammonite taxonomy, 13 bioevents can be identified in the interval from the Late Cenomanian to the Early Turonian (c. 3.5 myr) with each bioevent corresponding to a time interval of approximately 270,000 years, on average. They are consistent throughout several regions along the southern Tethys margin, though some gaps remain, at least at the stage boundary. These bioevents are correlated with the zonation defined for the stratotype (GSSP) of the base of the Turonian in the Western Interior (USA). The paleobiogeographic distribution of ammonites reveals some endemism but the predominant picture is that of a homogeneous fauna throughout the area, even though distinct Boreal and Western Tethys (Atlantic domain) marine influences are evident. An inter- pretation of the evolution of conch morphology and ornamentation through the zones of the Late CenomanianeEarly Turonian is proposed. Ó 2013 Elsevier Ltd. All rights reserved. 1. Introduction The present study analyses the spatial and temporal distribution of ammonites of the Upper Cenomanian and Lower Turonian along the southern margin of the Tethys from Morocco to Oman, inclusive of the Trans-Saharan Seaway as far south as northern Nigeria (Fig. 1). It is based on a critical compilation of our own data and those taken from the literature. The latter sources include Basse and Choubert (1959), Charrière et al. (1998), Meister and Rhalmi (2002), Kennedy et al. (2008), Lehmann and Herbig (2009) and Cavin et al. (2010) for Morocco (Pre-African Trough, High and Middle Atlas); Amédro et al. (1996), Busson et al. (1999), Chikhi-Aouimeur et al. (2011) and Benyoucef et al. (2012) for Algeria (Pre-African Trough, Atlas, Sahara); Robaszynski et al. (1990, 1993), Chancellor et al. (1994), Meister and Abdallah (1996, 2005, 2012) for central and southern Tunisia; Meister et al. (1992, 1994) for Niger (Damergou, Tenere); Reyment (1954), Barber (1957), Meister (1989), Courville et al. (1991), Zaborski (1993, 1995, 1996) and Courville (1993) for northern Nigeria; Rossi Ronchetti and Albanesi (1961) for Libya (Tripolitania); Allam (1986), Luger and Gröschke (1989), Kassab (1991 , 1996), Wiese and Schulze (2005), Nagm et al. (2010a, b) and Nagm and Wilmsen (2012) for Egypt (Libyan Desert, Eastern Desert); Freund and Raab (1969), Lewy and Raab (1978), Lewy et al. (1984), Aly and Abdel-Gawad (2001) and Kassab and Obaidalla (2001) for Egypt and Israel (Sinai and Negev); Basse (1940, 1954), Dubertret (1950), Dubertret and Wetzel (1956), Saint Marc (1974) and Wiese and Schulze (2005) for Lebanon; Mouty et al. (2003) for Syria (Palmyrides Chain); Aly et al. (2008) for Jordan; Powers et al. (1966), El-Khayal (1986) for Saudi Arabia; Kennedy and Simmons (1991) and Meister and Piuz (in prep.) for Oman (Adam foothills). These data are of variable reliability. The currently known distribution of the fauna and the high diversity in some areas could simply be a historical artefact due to the longer and more intensive investigation of areas such as northern Nigeria, Tunisia or Egypt, in comparison to regions such as Libya, Syria, Lebanon and the Arabian Peninsula, where knowledge is at a preliminary stage. 2. Biostratigraphical framework For the first time, a tentative synthetic range chart is proposed for Late CenomanianeEarly Turonian ammonites of the southern Tethys margin from Morocco to Oman (Figs. 2 and 3). This range chart is based on data published for this region. It should be borne in mind that the taxonomy and the stratigraphic records rely * Corresponding author. E-mail addresses: christian.meister@ville-ge.ch (C. Meister), andre.piuz@ville- ge.ch (A. Piuz). Contents lists available at SciVerse ScienceDirect Cretaceous Research journal homepage: www.elsevier.com/locate/CretRes 0195-6671/$ e see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.cretres.2013.03.009 Cretaceous Research xxx (2013) 1e21 Please cite this article in press as: Meister, C., Piuz, A., Late CenomanianeEarly Turonian ammonites of the southern Tethys margin from Morocco to Oman: Biostratigraphy, paleobiogeography and morphology, Cretaceous Research (2013), http://dx.doi.org/10.1016/j.cretres.2013.03.009