An Early Cretaceous vertebrate assemblage from the Cabao Formation of NW Libya

Abstract

-Fossil vertebrates from the Cabao Formation discovered in the area of Nalut in northwestern Libya include the hybodont shark Priohybodus, the crocodilian Sarcosuchus, an abelisaurid, a baryonichine spinosaurid and a large sauropod with spatulate teeth. The Cabao Formation may be Hauterivian to Barremian in age, although an earlier Berriasian to Valanginian age cannot be excluded. Its dinosaur assemblage is reminiscent of that of the El Rhaz and Tiouraren formations of Niger and strongly differs from both the Cenomanian assemblages of Morocco and Egypt and the Late Aptian to Albian fauna of Tunisia. Fossil vertebrates may be an important tool to establish the stratigraphical framework of the poorly dated Early Cretaceous continental deposits of Africa.

The “Continental Intercalaire” of southern Tunisia: Stratigraphy, paleontology, and paleoecology

“…This taxon has been previously reported from Late Jurassic deposits of Somalia, Ethiopia, Yemen, and Uruguay, as well as from the Early Cretaceous of Libya (Duffin, 2001;Perea et al, 2001;Cuny et al, 2004;Le Loeuff et al, 2010;Soto et al, 2012). In this study we consider this taxon as a biostratigraphic marker for the lower Douiret Formation.…”

“…Surface collection yielded a total of 2574 identifiable elements from the lower Douiret Formation (Sandy Member) and 2888 from the Oum ed Diab member providing a robust database for palaeontological interpretation (see Table 1). Vertebrate remains were compared with taxa described in the literature, in particular from Tunisia (Bouaziz et al, 1988;Benton et al, 2000;Buffetaut and Ouaja, 2002;Cuny et al, 2004Cuny et al, , 2010, Libya (Duffin, 2001;Smith and Dalla Vecchia, 2006;Le Loeuff et al, 2010;Smith et al, 2010), Egypt (Smith et al, 2001), Niger (Taquet, 1976;Broin, 1980;Taquet and Russell, 1999;Sereno et al, 1999Sereno et al, , 2001Sereno and Brusatte, 2008) and Morocco (Russell, 1998;Cavin et al, 2010).…”

“…and ''Pelomedusoides'' from the Douiret Formation. Pleurodiran chelonids have been also reported from coeval deposits of Libya (Cabao Formation, El-Zouki, 1980;Le Loeuff et al, 2010;Rubino et al, 2010) and from the Gadofaoua site in Niger (Broin, 1980;Rauhut and Lòpez-Arbarello, 2009). Similarly, indeterminate pleurodiran remains have been reported from the Early Cretaceous of northern Brazil (Candeiro et al, 2011), whereas Cenomanian representatives of four groups of Pleomedusoides have been recognized in the Kem Kem beds of Morocco (see Torices et al, in press).…”

“…In fact, with the exception of few fossil-bearing beds, much of the deposits are barren of fossils and those recovered provide environmental rather than biostratigraphic information. Thus, the entire succession has been primarily dated on correlation with marine-equivalent deposits to the north and by correlations far east with their Libyan counterparts Ben Youssef and Peybernès, 1986;Abdallah and Memmi, 1994;Bouaziz, 1995;Duffin, 2001;Bodin et al, 2010;Le Loeuff et al, 2010). As a consequence, the age of fossil-bearing strata based on indirect evidences can result very inaccurate.…”

Continental fossil vertebrates from the mid-Cretaceous (Albian–Cenomanian) Alcântara Formation, Brazil, and their relationship with contemporaneous faunas from North Africa

“…Cretaceous faunal similarities between continental Africa and South America are widely documented in the dinosaurian fossil record (e.g., Calvo and Salgado, 1995;Russell, 1996;Sereno et al, 1996Sereno et al, , 1998Sereno et al, , 1999Sereno et al, , 2004Forster, 1999;Sues et al, 2002;Upchurch et al, 2002;Candeiro et al, 2004Candeiro et al, , 2006Holtz et al, 2004;Coria and Currie, 2006;Wilson, 2006;Sereno and Brusatte, 2008;Cavin et al, 2010;Le Loeuff et al, 2010;Smith et al, 2010). However, it is important to view paleontological discoveries in light of stratigraphic and paleogeographic data when generating and evaluating paleobiogeographic hypotheses.…”