New information on ornithopod dinosaurs from the Late Jurassic of Portugal FILIPPO MARIA ROTATORI, MIGUEL MORENO-AZANZA, and OCTÁVIO MATEUS Rotatori, F.M., Moreno-Azanza, M., and Octávio, M. 2020. New information on ornithopod dinosaurs from the Late Jurassic of Portugal. Acta Palaeontologica Polonica 65 (1): 35–57. Ornithopods are one of the most speciose group of herbivorous dinosaurs, rising during the Jurassic and getting extinct at the Cretaceous–Paleogene boundary. However, most of the attention has been given to derived forms (hadrosaurids). Herein, cranial and post-cranial ornithopod material from the Upper Jurassic Lourinhã Formation and housed at Museu da Lourinhã is described and discussed. Comparison and phylogenetic analyses has allowed the attribution of the material either to Dryosauridae or to Ankylopollexia. The large-sized taxa conservatively ascribed to Ankylopollexia, resemble more closely Early Cretaceous styracosternans than Late Jurassic taxa. Due to the lack of autapomorphic characters, it was not possible to assign the material to any of the two valid Jurassic ornithopod Portuguese species, Draconyx lou- reiroi and Eousdryosaurus nanohallucis, although phylogenetic analyses hint a close relationship between the Lourinhã dryosaurid material and E. nanohallucis. Principal Component Analysis plotting limb bones proportions indicates a not fully mature ontogenetic stage for the Portuguese specimens. Comparing the Portuguese ornithopod fauna with the one in Morrison Formation and Kimmeridge Clay Formation, it is remarked the key-role of Portugal to understand biogeo- graphic patterns in the distribution of iguanodontians. Key words: Dinosauria, Ornithischia, Iguanodontia, taxonomy, systematics, biogeograhy, Jurassic, Lourinhã Forma- tion, Portugal. Filippo Maria Rotatori [[email protected]], Miguel Moreno-Azanza [[email protected]], and Octávio Mateus [[email protected]], GeoBioTec, Department of Earth Sciences, Faculdade de Ciências e Tecnologia, FCT, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal; Museu da Lourinhã, Espaço Novapaleo, Rua João Luis de Moura 95, 2530-158 Lourinhã, Portugal. Received 5 August 2019, accepted 4 December 2019, available online 4 March 2020. Copyright © 2020 F.M. Rotatori et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License (for details please see http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. the North American Morrison Formation, and from the Introduction Tanzanian Tendaguru Formation (Gilmore 1909; Janensch 1955; Galton 1981; Carpenter and Wilson 2008; McDonald Ornithopods are among the most successful groups of di- nosaurs from the Mesozoic. They range from the Jurassic 2011), while European faunas are far less abundant. From (Ruiz-Omeñaca et al. 2006) to the end of the Cretaceous Portugal, the Guimarota Mine lignites yielded a rich fos- (Horner et al. 2004). Ornithopoda contains some iconic siliferous assemblage, providing significant insights on the species and some of the very first taxa known to paleontol- structure of Late Jurassic ecosystems (Martin and Krebs ogy (Horner et al. 2004; Norman 2004). Systematic studies 2000). Among the dinosaurian fauna, in 1973 Thulborn with cladistic approaches on the Ornithopoda began in the erected the species Phyllodon henkeli, a small ornithis- 1980s (Norman 1984; Sereno 1984, 1986) and for a long chian which appears to be closely related to Drinker nisti time the relationships within the clade remained stable. and Othnielosaurus rex from the Morrison Formation However, in recent years, many systematic revisions chal- (Martin and Krebs 2000). Rauhut (2001) described a large lenged the very first phylogenetic hypothesis (Butler et sample of herbivorous dinosaur material from Guimarota, al. 2008; Boyd 2015; Madzia et al. 2018). These revisions reporting on over 100 teeth and a fragmentary dentary affected primarily the base of Ornithopoda (non-iguano- ascribed to Phyllodon, and proposed a diagnosis of the dontian ornithopods), while more derived taxa maintained species based on the arrangement and proportion of the stable positions. Jurassic basal iguanodontians are a rare tooth ridges. In addition, Rauhut (2001) reported three component of terrestrial faunal assemblages (Foster 2007). dentary teeth ascribed to indeterminate iguanodontians. The majority of the taxa and specimens are known from From the Upper Callovian locality of Pedrógao, in Leiria Acta Palaeontol. Pol. 65 (1): 35–57, 2020 https://doi.org/10.4202/app.00661.2019 36 ACTA PALAEONTOLOGICA POLONICA 65 (1), 2020 municipality, Thulborn (1973) erected the taxon Alocodon Geological settings kuehnei based on isolated teeth. Most of the Late Jurassic ornithischians of Portugal come from the outcrops of the Specimens described here were recovered along the coastline Lourinhã Formation (Antunes and Mateus 2003) includ- in the Lourinhã municipality, western-central Portugal, from ing Trimucrodon cuneatus and cf. Hypsilophodon from a north-south transect that goes from north Vale Pombas to the Porto Dinheiro locality (Thulborn 1973). Due to the Santa Rita municipality (Fig. 1). All specimens come from fragmented state of the specimens and the paucity of sub- the famous and highly fossiliferous Upper Jurassic Lourinhã sequent discoveries, a clear assessment of this material is Formation (Kimmeridgian–Tithonian; Hill 1989). This litho- problematic (Norman et al. 2004). Two undisputed iguano- stratigraphic unit comprises a succession of sandstone and dontian species were recovered from Lourinhã Formation: mudstone beds, representing braided fluvial systems, allu- the camptosaurid Draconyx loureiroi (Mateus and Antunes vial fans and upper deltas, with the occasional presence of 2001) and the dryosaurid Eousdryosaurus nanohallucis shallow marine limestone that represent short transgressive (Escaso et al. 2014). The holotypes consist of fragmen- events. The subdivision of the Lourinhã Formation into sub- tary post-cranial elements. D. loureiroi has been treated as units has been subjected to various revisions (Hill 1989; a wildcard in several phylogenetic analyses dealing with Manuppella 1998; Manuppella et al. 1999; Taylor et al. 2014). basal iguanodontians relationships (McDonald 2012; Boyd In the present work, we follow the subdivision proposed by Mateus et al. (2017). From bottom to top, the beds outcrop- 2015), while E. nanohallucis is represented by an immature ping belong to the following members: Porto Novo/Praia de individual (Escaso et al. 2014). The scarcity of ornithopod Amoreira, Praia Azul, Santa Rita. and, in general, neornithischian remains, strongly contrasts Porto Novo/Praia da Amoreira Member is characterized with the abundance of other herbivorous dinosaurs, such as by a percentage of sands that range 34–44%, and are formed sauropods and thyreophorans (Antunes and Mateus 2003). of fluvial channel deposits and calcrete-bearing floodplain Up until now it has not been possible to assess if this gap mud with occasional fine sand lenses. The depositional en- may be due to differential preservation linked to ecologi- vironment is interpreted as either distal mudflat of an al- cal segregation as seen for ornithischians and saurischians luvial fan, or of a braided river system. It is dated to the in the Morrison Formation (Foster 2013) or if it reflects uppermost Kimmeridgian (Fig. 1) (Hill 1989; Taylor et al. inter-specific competition between different herbivorous 2014; Mateus et al. 2017). taxa. Beside skeletal and dental ornithopod fossils, various Praia Azul Member is characterized by a lower per- tracks and track-sites have been reported from the Lourinhã centage of sand with respect to the underlying Porto Novo/ Formation (Mateus and Milàn 2009) including a giant sized Praia da Amoreira Member, ranging 12–25%. Three ex- Iguanodontipus-like footprint which is 70 cm long, sug- tensive carbonated shell layers, representing three marine gesting the presence of a large sized iguanodontian possibly transgression events, can be correlated along the whole ba- larger than any previously known Late Jurassic species sin, being important marker beds (Hill 1989). This mem- (Mateus and Milàn 2008), but also smaller sized camp- ber is dated to the Kimmeridgian–Tithonian interval, being tosaurid tracks (as figured by Antunes and Mateus 2003: the boundary between these two stages corresponding to fig. 11) and Dinehichnus-like ones, probably made by dryo- the second carbonated layer (Hill 1989; Taylor et al. 2014; saurids or other small bipedal neornithischians (Mateus Mateus et al. 2017). and Milàn 2009). Santa Rita Member is constituted mainly of mudstone with numerous pedogenic carbonated concretions, interca- Here, we extend the current knowledge of the Late lated by levels of cross-bedded sandstone. The sandstone Jurassic ornithopod fauna of Portugal, reporting and de- elements include large scale point bars, flat tabular lenses, scribing previously unpublished fossils housed at the Museu crevasse splay, and levees bodies. This is the youngest mem- da Lourinhã. ber, being dated to Tithonian (Mateus et al. 2017). Institutional abbreviations.—CM, Carnegie Museum of Natural History, Pittsburgh, PA, USA; IRSNB, Institut Royal des Sciences Naturelles de Belgique, Brussels, Bel gium; Material and methods NHMUK, Natural History Museum, London, UK; OUM, Oxford University Museum,