Biogeographical affinities of Late Cretaceous continental tetrapods of Europe: a review

The continental tetrapod assemblages from the Santonian-Maastrichtian of Europe consist of dinosaurs (theropods: Abelisauroidea, Alvarezsauridae, Dromaeosauridae, ?Oviraptorosauria, ?Troodontidae, and birds: Enantiornithes, basal Ornithtirae; sauropods: Titanosauria; ankylosaurs: Nodosauridae; ornithopods: Hadrosauridae, Rhabdodontidae; and neoceratopsians), pterosaurs (Azhdarchidae), crocodyliforms (eusuchians: Alligatoroidea, Gavialoidea, ?Hylaeochampsidae; sebecosuchian-like ziphosuchians; and, probably, basal neosuchians), choristoderes (?Champsosauridae), squamates (lacertilians: Iguanidae s.l., Paramacellodidae, Polyglyphanodontinae, Varanoidea; snakes: Madtsoiidae; possible atnphishaenians), turtles (cryptodires: Chelydroidea, Kallokibotionidae, Soletnydidae; pleurodires: Bothremydidae, Dorlokidae), lissamphibians (Albanerpetontidae; anurans: Discoglossidae, Palacobatrachidae; caudates: Batrachosauroididae, Salamandridae), and mammals (multituberculates: Kogaionidae, ?Paracimexomys group; marsupials: Herpetotheriidae; eutherians: Zhelestidae). The palaeobiogeographical affinities of the Late Cretaceous continental tetrapods of Europe are complex. The faunas are commonly considered to show a mixed pattern resulting from the addition of Asamerican and Gondwanan forms to European taxa. Albanerpetontids, both paramacellodid and polyglyphonodontine lizards, and hadrosaurid dinosaurs are taxis with Palaeolaurasian (or, in some case, even Neopangean) affinities. Other forms, such as paleobatrachid and batrachosauroidid lissamphibians, solemydid turtles, alligatoroid crocodyliforms, and nodosaurid dinosaurs can be considered as Euramerican taxa. Kallokibotionid and dortokid turtles, rhabdodontid dinosaurs and kogaionid mammals are endemic to Europe. The Gondwanan taxa have been regarded as African immigrants that reached southern Europe via the Mediterranean Tethyan sill. Abelisaurid and titanosaurid dinosaurs, trematochampsid crocodyliforms, podoenemidid and bothremydid turtles, and boid and madtsoiid snakes constitute the basic pattern of the so-called Eurogondwanan fauna. However, the validity of some of these taxa is a disputed matter (Titanosauridae, Trematochampsidae), and the presence of other taxa in the Late Cretaceous of Europe is based on controversial data (Boidac, Podoenemididae). Only Abelisauroidea, Madtsoiidae and Bothremydidae (and, yet for confirming, Sebecosuchia) provide evidence of interchanges between Africa and Europe. At least abelisauroids might have reached Europe before the Late Cretaceous. In conclusion, most of the continental tetrapod taxa from the latest Cretaceous of Europe show affinities with those of northern Hemisphere landmasses. Latest Cretaceous trans-Tethyan dispersal events between Africa and Europe remain poorly documented.