The “mid”-Cretaceous (Lower Cenomanian) Continental Vertebrates of Gara Samani, Algeria. Sedimentological Framework and Palaeodiversity

Abstract

Excellent outcrops of the upper part of the “Continental Intercalaire” deposits occur in the Gara Samani area, southern Algeria. These strata are recognised herein as belonging to the Gara Samani Formation, which is composed of the Samani Vertebrate-rich Sand Member, the Samani Sandstone Member and the Méguidène Stratified Sand Member. The first two members are from a fluvial system and the last member corresponds to an aeolian (dune and interdune) system. They have preserved one of the most diverse continental vertebrate faunas of latest Albian–early Cenomanian age yet known from northern Africa. Most of the taxa identified there, cited for the first time for the “mid”-Cretaceous of Algeria, have not been analysed in detail so far; and many of them have never been figured. The faunal list of vertebrates from this locality was supplemented thanks to detailed analysis of new and relatively abundant finds. As a consequence, the Gara Samani vertebrate assemblage is recognised as composed of elasmobranchs (two Hybodontiformes, i.e., Tribodus sp. and Distobatidae indet.; and a Batoidea, Onchopristis numida), actinopterygians (Bawitius sp., Adrianaichthys sp., Obaichthys africanus, and Calamopleurus africanus), sarcopterygians (Mawsoniidae indet. and the Dipnoi, cf. Lavocatodus humei and Neoceratodus africanus), testudines (at least two Pelomedusoides, one of them being a representative of Araripemydidae), crocodyliforms (all remains being compatible with Neosuchia, represented at least by Elosuchus broinae), ornithocheirid pterosaurs, and non-avian dinosaurs (titanosauriform sauropods and at least two theropods, Spinosaurus aegyptiacus and Carcharodontosaurus saharicus). This fauna association displays close similarities to contemporaneous ones from North Africa, especially with that from the Kem Kem beds.

Isolated tooth reveals hidden spinosaurid dinosaur diversity in the British Wealden Supergroup (Lower Cretaceous)

“…However the quantitative evidence presented herein corroborates previous suggestions that XMDFEC V10010 cannot be referred to Spinosauridae ( Buffetaut et al, 2019 ; Katsuhiro & Yoshikazu, 2017 ; Soto, Toriño & Perea, 2020 ). With the Patagonian late Cenomanian-early Turonian tooth referred to Spinosauridae in Salgado et al (2009) also likely from a different theropod lineage ( Soto, Toriño & Perea, 2020 ), the youngest definitive spinosaurid remains appear to come from Cenomanian deposits of Africa ( Benyoucef et al, 2022 ; Ibrahim et al, 2020b ; Sereno et al, 2022 ).…”

“…Spinosaurid skeletal material is rare ( Hone, Xu & Wang, 2010 ), but tooth crowns attributed to the group are regularly discovered; numerous isolated specimens have been reported from England ( Charig & Milner, 1997 ; Fowler, 2007 ; Martill & Hutt, 1996 ; Turmine-Juhel et al, 2019 ), Spain ( Alonso & Canudo, 2016 ; Isasmendi et al, 2020 ; Ruiz-Omeñaca et al, 2005 ), China ( Buffetaut et al, 2008 ; Shu’an, Pei & Daolin, 2022 ), Malaysia ( Sone et al, 2015 ), Japan ( Hasegawa et al, 2003 ; Katsuhiro & Yoshikazu, 2017 ), Thailand ( Buffetaut & Ingavat, 1986 ; Buffetaut et al, 2019 ; Wongko et al, 2019 ), Algeria ( Benyoucef et al, 2015 ; Benyoucef et al, 2022 ), Cameroon ( Congleton, 1990 ), Morocco ( Richter, Mudroch & Buckley, 2013 ), Libya ( Le Loeuff et al, 2010 ), Niger ( Sereno et al, 1998 ), Tunisia ( Benton et al, 2000 ; Bouaziz et al, 1988 ) and Brazil ( Lacerda et al, 2023 ; Medeiros, 2006 ; Sales et al, 2017 ) (see also Bertin (2010) for further references and notes). Putative spinosaurid dental material may also extend the temporal span of the clade, though reported teeth from the Jurassic of France ( Vullo et al, 2014 ), Tanzania ( Buffetaut, 2012 ) and Niger ( Serrano-Martínez et al, 2015 ; Serrano-Martínez et al, 2016 ), as well as the Late Cretaceous of China ( Hone, Xu & Wang, 2010 ) and Patagonia ( Salgado et al, 2009 ), likely belong to other archosaur clades ( Hendrickx et al, 2019 ; Soto, Toriño & Perea, 2020 ).…”

A peirosaurid mandible from the Albian–Cenomanian (Lower Cretaceous) of Algeria and the taxonomic content of Hamadasuchus (Crocodylomorpha, Peirosauridae)

“…1971; Lefranc & Toutin 1971; Lefranc & Guiraud 1990; Busson & Cornée 1991; de Lapparent de Broin 2002; Meunier & Larsson 2017; Benyoucef et al . 2022). La Gara Samani has yielded a diverse fauna including crocodylomorphs (de Lapparent de Broin et al .…”

On the Occurrence of the Gar Obaichthys africanus Grande in the Cretaceous of Portugal: Palaeoecological and Palaeobiogeographical Implications

“…123, 127, figures 1C-E, 4A-H), [48] (pp. 49, figure 5L), [49] (pp. 9-10, figure 8M), [50] (table 8, figure 61I-J), [51] (pp.…”

“…In Spain, O. africanus scales have been identified in Cenomanian coastal deposits of the Cantabrian Ranges, in La Cabaña [60], and the Iberian Ranges, in Algora [47,51,52]. Outside Iberia, O. africanus has been recorded in the Cenomanian of France [45,46]; Morocco, e.g., [18,43,50,61]; Algeria [48,49]; and Egypt [13] (Figure 5). Some scales attributed to Stromerichthys have been reported from the Albian of the Congo Basin [62] (pl.4, figures 15-16), but they could belong to different Obaichthyidae which present affinities with correlative Brazilian forms [18].…”