Diversity, Relationships, and Biogeography of the Lambeosaurine Dinosaurs from the European Archipelago, with Description of the New Aralosaurin Canardia garonnensis

Abstract

We provide a thorough re-evaluation of the taxonomic diversity, phylogenetic relationships, and historical biogeography of the lambeosaurine hadrosaurids from the European Archipelago. Previously published occurrences of European Lambeosaurinae are reviewed and new specimens collected from upper Maastrichtian strata of the south-central Pyrenees are described. No support is found for the recognition of European saurolophines in the available hadrosaurid materials recovered so far from this area. A new genus and species of basal lambeosaurine, Canardia garonnensis, is described on the basis of cranial and appendicular elements collected from upper Maastrichtian strata of southern France. C. garonnensis differs from all other hadrosaurids, except Aralosaurus tuberiferus, in having maxilla with prominent subrectangular rostrodorsal flange; it differs from A. tuberiferus in a few maxillary and prefrontal characters. Together with A. tuberiferus, C. garonnensis integrates the newly recognized tribe Aralosaurini. Inference of lambeosaurine interrelationships via maximum parsimony analysis indicates that the other three known European lambeosaurines are representatives of two additional subclades (tribes) of these hadrosaurids: Tsintaosaurini (Pararhabdodon isonensis) and Lambeosaurini (the Arenysaurus ardevoli-Blasisaurus canudoi clade). The tribes Aralosaurini, Tsintaosaurini, Lambeosaurini, and Parasaurolophini are formally defined and diagnosed for the first time. Three event-based quantitative methods of ancestral range reconstruction were implemented to infer the historical biogeography of European lambeosaurines: Dispersal-Vicariance Analysis, Bayesian Binary MCMC, and Dispersal-Extinction-Cladogenesis. The results of these analyses, coupled with the absence of pre-Maastrichtian lambeosaurines in the Mesozoic vertebrate fossil record of Europe, favor the hypothesis that aralosaurins and tsintaosaurins were Asian immigrants that reached the Ibero-Armorican island via dispersal events sometime during the Maastrichtian. Less conclusive is the biogeographical history of European lambeosaurins; several scenarios, occurring sometime during the Maastrichtian, are possible, from vicariance leading to the splitting of Asian or North American from European ranges to a dispersal event from North America to the European Archipelago.

The Molí del Baró-1 site, a diverse fossil assemblage from the uppermost Maastrichtian of the southern Pyrenees (north-eastern Iberia)

“…Moreover, these authors estimated that nearly the 25% of the teeth from Iberian localities showed anterior denticles. However, the studied specimens differ from the tooth described by Prieto-M arquez et al (2000) in having the posterior carina placed in the medial plane of the crown and totally denticulated. The multivariate analysis carried out by Torices et al (in press) revealed clear differences among the specimen studied by Prieto-M arquez and collaborators and the remaining Iberian sample.…”

“…The relatively small size of the denticles suggests affinity to Richardoestesia (Currie et al, 1990;Sankey et al, 2002;Llorens, 2010). MCD5033 resembles the Richardoestesia specimen from the lower Maastrichtian of the L'Abeller locality in the Eastern Tremp Syncline (Prieto-M arquez et al, 2000). However, unlike the tooth described by Prieto-M arquez et al (2000), the studied specimen has the caudal carina symmetrically placed in the crown and totally denticulated.…”

“…MCD5033 resembles the Richardoestesia specimen from the lower Maastrichtian of the L'Abeller locality in the Eastern Tremp Syncline (Prieto-M arquez et al, 2000). However, unlike the tooth described by Prieto-M arquez et al (2000), the studied specimen has the caudal carina symmetrically placed in the crown and totally denticulated. As mentioned above, it is important to note that the specimen described by Prieto-M arquez et al (2000) probably belongs to a different taxon to Richardoestesia (Torices et al, in press).…”

“…However, unlike the tooth described by Prieto-M arquez et al (2000), the studied specimen has the caudal carina symmetrically placed in the crown and totally denticulated. As mentioned above, it is important to note that the specimen described by Prieto-M arquez et al (2000) probably belongs to a different taxon to Richardoestesia (Torices et al, in press). Taking into account all these evidence, MCD5033 is assigned to an indeterminate theropod morphotype.…”

Late cretaceous continental and marine vertebrate assemblages from the Laño quarry (Basque-Cantabrian Region, Iberian Peninsula): an update

“…The isolation from other landmasses may have facilitated the survival of relict (vicariant) taxa in Europe until Campanian-Maastrichtian times. Moreover, dispersal events between Asia (and, tentatively, between North America) and Europe have been documented during the Late Cretaceous (see Weishampel et al, 2010;Prieto-Márquez et al, 2013;Csiki et al, 2015 and references therein). The faunal exchanges that are hypothesized to occur between the Gondwanan landmasses and Europe during the Late Cretaceous are still matters of debate (Gheerbrant and Rage, 2006).…”