Book of abstracts of the 5th Symposium on Mesozoic and Decapod Crustaceans

Stegosaurian dinosaurs have a quadrupedal stance, short forelimbs, short necks, and are generally considered to be low browsers. A new stegosaur, Miragaia longicollum gen. et sp. nov., from the Late Jurassic of Portugal, has a neck comprising at least 17 cervical vertebrae. This is eight additional cervical vertebrae when compared with the ancestral condition seen in basal ornithischians such as Scutellosaurus.
Miragaia has a higher cervical count than most of the iconically long-necked sauropod dinosaurs. Long neck length has been achieved by ‘cervicalization’ of anterior dorsal vertebrae and probable lengthening of centra. All these anatomical features are evolutionarily convergent with those exhibited in the necks of
sauropod dinosaurs. Miragaia longicollum is based upon a partial articulated skeleton, and includes the only known cranial remains from any European stegosaur. A well-resolved phylogeny supports a new clade that unites Miragaia and Dacentrurus as the sister group to Stegosaurus; this new topology challenges the common view of Dacentrurus as a basal stegosaur.

The precursor of the North Atlantic existed between the North American and Iberian blocks from the earliest Jurassic Hettangian and has been ever expanding since. By the Kimmeridgian and Tithonian, when much of the Morrison Fm rocks were deposited, the proto-Atlantic was more than 300 km wide at 27° paleolatitude between North America and Iberia. Macrovertebrate paleontology reveals a unique story to the isolation of Iberia and instead suggest a paleogeographic land connection between North American and Iberia. Torvosaurus, Allosaurus, Ceratosaurus, Stegosaurus, Supersaurus and others have a distribution restricted to Morrison Formation in North America and Lourinhã Formation in Portugal. A novel paleogeographic model is here suggested: (1) around the Middle–Late Jurassic transition there is a major palaeoceanographic and palaeoclimatic reorganization, coincidental to a major eustatic sea-level drop and uplift associated with the Callovian– Oxfordian Atlantic Regressive Event; (2) creating an ephemeral land bridge presenting a temporary opportunity for terrestrial gateways likely across the Flemish Cap and Galician Bank land masses, allowing large dinosaurian taxa to cross the northern proto-Atlantic in both directions; (3) finally, a Callovian–Oxfordian faunal exchange around the 163 Ma, through latest Kimmeridgian at 152 Ma (the age of equivalent genera in both Morrison and Portugal), is was an interval that allowed speciation, but retaining generic similarity of vertebrates. This model is consistent with the chronology and taxonomy required for speciation of the Iberian and American forms, exemplified by the coeval sister-taxa pairs Torvosaurus tanneri and T. gurneyi, Allosaurus fragilis and A. europaeus, or Supersaurus vivianae and S. lourinhanensis. While some of the smaller animals in the fauna show Morrison/Portugal affinities, most from Iberia have European or even Asian affinities. The larger-bodied fauna are more closely related to Morrison than to mainland Europe (except for dacentrurine stegosaurs). The body size differences and affinities of taxa across paleogeography is comparable to what is observed today across the Wallace Line. Migration may have also occurred in both directions. The closest relative of Torvosaurus is likely the European Bathonian Megalosaurus, thus the presence of the genus in North America represents a European migration. On other hand, Allosaurus and Supersaurus origins are consistent with a North American origin, representing an westto-east migration.

dinosaur genera Diceratops Lull, 1905 and Microceratops Bohlin, 1953 are preoccupied by the Hymenoptera insects, Diceratops Foerster, 1868 and Microceratops Seyrig, 1952, respectively. Therefore, the name of the ceratopsian dinosaur Diceratops Lull, 1905 from the Late Cretaceous of United States is a junior homonym of the hymenoptera Diceratops Foerster, 1868. Diceratus n. gen. (Greek di ‘‘two,’’ Greek ceratos ‘‘horned’’) is proposed as the replacement name of Diceratops Lull, 1905. Some workers have considered Diceratops synonymous with Triceratops (e.g., Dodson and Currie, 1990) but it was reinstated by Forster (1996) after analysis of the characteristics of all existing ceratopsid skulls, and recent reviews (e.g., Dodson et al., 2004) have considered Diceratops a valid genus.
Due to preoccupation, the name of the ceratopsian dinosaur Microceratops Bohlin, 1953 from the Cretaceous of the Gobi is
a junior homonym of the insect Microceratops Seyrig, 1952. Microceratus n. gen. (Greek micro ‘‘small,’’ Greek ceratos ‘‘horned’’) is proposed as the replacing name of Microceratops Bohlin, 1953.
Sereno (2000:489) has declared Microceratops a nomen dubium since the holotype material lacks any diagnostic features, a
convention followed by You and Dodson (2004:480). However, the name is still used by Le Loeuff et al. (2002), Lucas (2006),
Alifanov (2003) and Xu et al. (2002), and such practice justifies the renaming of the genus.
In order to preserve some stability, the names chosen here deliberately preserve the same prefixes.

Here we describe a new partial sauropod skeleton from the late Kimmeridgian (Late Jurassic) of the Lourinhã Formation, central west Portugal. The closely associated specimen comprises a complete tooth (with root), a fragment of cervical neural arch, an anterior chevron, and an almost complete right pectoral girdle and forelimb. The new sauropod, Zby atlanticus, n. gen. et sp., can be diagnosed on the basis of four autapomorphies, including a prominent posteriorly projecting ridge on the humerus at the level of the deltopectoral crest. Nearly all anatomical features indicate that Zby is a non-neosauropod eusauropod. On the basis of several characters, including tooth morphology, extreme anteroposterior compression of the proximal end of the radius, and strong beveling of the lateral half of the distal end of the radius, Zby appears to be closely related to Turiasaurus riodevensis from approximately contemporaneous deposits in eastern Spain. However, these two genera can be distinguished from each other by a number of features pertaining to the forelimb. Whereas previously described Late Jurassic Portuguese sauropods show close relationships with taxa from the contemporaneous Morrison Formation of North America, it appears that turiasaurians were restricted to Europe. All adult sauropods recovered in the Late Jurassic of Portugal thus far are very large individuals: it is possible that the apparent absence of small- or medium-sized adult sauropods might be related to the occupation of lower-browsing niches by non-sauropods such as the long-necked stegosaur Miragaia longicollum.

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This article presents a synthesis of Palaeozoic and Mesozoic fossil tetrapods from Greenland, including an updated review of the holotypes and a new photographic record of the main specimens. All fossil tetrapods found are from East Greenland, with at least 30 different known taxa: five stem tetrapods (Acanthostega gunnari, Ichthyostega eigili, I. stensioi, I. watsoni, and Ymeria denticulata) from the Late Devonian of the Aina Dal and Britta Dal Formations; four temnospondyl amphibians (Aquiloniferus kochi, Selenocara groenlandica, Stoschiosaurus nielseni, and Tupilakosaurus heilmani) from the Early Triassic of the Wordie Creek Group; two temnospondyls (Cyclotosaurus naraserluki and Gerrothorax cf. pulcherrimus), one testudinatan (cf. Proganochelys), two stagonolepids (Aetosaurus ferratus and Paratypothorax andressorum), the eudimorphodontid Arcticodactylus, undetermined archosaurs (phytosaurs and both sauropodomorph and theropod dinosaurs), the cynodont Mitredon cromptoni, and three mammals (Haramiyavia clemmenseni, Kuehneotherium, and cf. ?Brachyzostrodon), from the Late Triassic of the Fleming
Fjord Formation; one plesiosaur from the Early Jurassic of the Kap Stewart Formation; one plesiosaur and one ichthyosaur from the Late Jurassic of the Kap Leslie Formation, plus a previously unreported Late Jurassic plesiosaur from Kronprins Christian Land. Moreover, fossil tetrapod trackways are known from the Late Carboniferous (morphotype Limnopus) of the Mesters Vig Formation and at least four different morphologies (such as the crocodylomorph Brachychirotherium, the auropodomorph Eosauropus and Evazoum, and the theropodian Grallator) associated to archosaurian trackmakers are known from the Late Triassic of the Fleming Fjord Formation. The presence of rich fossiliferous tetrapod sites in East Greenland is linked to the presence of well-exposed continental and shallow marine deposits with most finds in terrestrial deposits from the Late Devonian and the Late Triassic.

Eggshells from the three extant crocodilian species Crocodylus mindorensis (Philippine Crocodile), Paleosuchus palpebrosus (Cuvier's Smooth-fronted Caiman or Musky Caiman) and Alligator mississippiensis (American Alligator or Common Alligator) were prepared for thin section and scanning electron microscope analyses and are described in order to improve the knowledge on crocodilian eggs anatomy and microstructure, and to find new apomorphies that can be used for identification. Both extant and fossil crocodilian eggs present an ornamentation that vary as anastomo-, ramo- or the here newly described rugosocavate type. The angusticaniculate pore system is a shared character for Crocodylomorpha eggshells and some dinosaurian and avian groups. Previously reported signs of incubated crocodilian eggs were found also on our only fertilised and hatched egg. Paleosuchus palpebrosus presents unique organization and morphology of the three eggshell layers, with a relatively thin middle layer characterised by dense and compact tabular microstructure.

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ABSTRACTCyclotosaurus naraserluki, sp. nov., is a new Late Triassic capitosaurid amphibian from lacustrine deposits in the Fleming Fjord Formation of the Jameson Land Basin in Greenland. It is based on a fairly complete and well-preserved skull associated with two vertebral intercentra. Previously reported as Cyclotosaurus cf. posthumus, C. naraserluki is unique among cyclotosaurs for having the postorbitals embaying the supratemporals posteromedially. The anterior palatal vacuity presents an autapomorphic complete subdivision by a wide medial premaxillary-vomerine bony connection. The parasphenoid projects between the pterygoids and the exoccipitals, preventing a suture between the two, a primitive condition shared with Rhinesuchidae, Eryosuchus, and Kupferzellia. Within Cyclotosaurus, the Greenlandic skull has a distinctive combination of circular choanae (shared with C. ebrachensis, C. posthumus, and C. robustus) and a convex posteromedial margin of the tabulars (also present in C. ebrachensis and C. intermedius). A phylogenetic analysis indicates that C. naraserluki is the sister taxon of the middle Norian C. mordax from southern Germany, with which it shares a pair of premaxillary foramina. Cyclotosaurus is one of the most successful and diverse genera of Late Triassic temnospondyls, with at least eight species reported from middle Carnian to late Norian. Cyclotosaurus naraserluki is the largest amphibian ever reported from Greenland and one of the Late Triassic vertebrates with the highest northern paleolatitude currently known.http://zoobank.org/urn:lsid:zoobank.org:pub:43AAA541-031C-4EE1-B819-4846EBBD1BBBSUPPLEMENTAL DATA?Supplemental materials are available for this article for free at www.tandfonline.com/UJVPCitation for this article: Marzola, M., O. Mateus, N. H. Shubin, and L. B. Clemmensen. 2017. Cyclotosaurus naraserluki, sp. nov., a new Late Triassic cyclotosaurid (Amphibia, Temnospondyli) from the Fleming Fjord Formation of the Jameson Land Basin (East Greenland). Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2017.1303501.ABSTRACTCyclotosaurus naraserluki, sp. nov., is a new Late Triassic capitosaurid amphibian from lacustrine deposits in the Fleming Fjord Formation of the Jameson Land Basin in Greenland. It is based on a fairly complete and well-preserved skull associated with two vertebral intercentra. Previously reported as Cyclotosaurus cf. posthumus, C. naraserluki is unique among cyclotosaurs for having the postorbitals embaying the supratemporals posteromedially. The anterior palatal vacuity presents an autapomorphic complete subdivision by a wide medial premaxillary-vomerine bony connection. The parasphenoid projects between the pterygoids and the exoccipitals, preventing a suture between the two, a primitive condition shared with Rhinesuchidae, Eryosuchus, and Kupferzellia. Within Cyclotosaurus, the Greenlandic skull has a distinctive combination of circular choanae (shared with C. ebrachensis, C. posthumus, and C. robustus) and a convex posteromedial margin of the tabulars (also present in C. ebrachensis and C. intermedius). A phylogenetic analysis indicates that C. naraserluki is the sister taxon of the middle Norian C. mordax from southern Germany, with which it shares a pair of premaxillary foramina. Cyclotosaurus is one of the most successful and diverse genera of Late Triassic temnospondyls, with at least eight species reported from middle Carnian to late Norian. Cyclotosaurus naraserluki is the largest amphibian ever reported from Greenland and one of the Late Triassic vertebrates with the highest northern paleolatitude currently known.http://zoobank.org/urn:lsid:zoobank.org:pub:43AAA541-031C-4EE1-B819-4846EBBD1BBBSUPPLEMENTAL DATA?Supplemental materials are available for this article for free at www.tandfonline.com/UJVPCitation for this article: Marzola, M., O. Mateus, N. H. Shubin, and L. B. Clemmensen. 2017. Cyclotosaurus naraserluki, sp. nov., a new Late Triassic cyclotosaurid (Amphibia, Temnospondyli) from the Fleming Fjord Formation of the Jameson Land Basin (East Greenland). Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2017.1303501.

We report a new specimen of the plesiosaur Cardiocorax mukulu that includes the most complete plesiosaur skull from sub-Saharan Africa. The well-preserved three-dimensional nature of the skull offers rare insight into the cranial anatomy of elasmosaurid plesiosaurians. The new specimen of Cardiocorax mukulu was recovered from Bentiaba, Namibe Province in Angola, approximately three meters above the holotype. The new specimen also includes an atlas-axis complex, seventeen postaxial cervical vertebrae, partial ribs, a femur, and limb elements. It is identified as Cardiocorax mukulu based on an apomorphy shared with the holotype where the cervical neural spine is approximately as long anteroposteriorly as the centrum and exhibits a sinusoidal anterior margin. The new specimen is nearly identical to the holotype and previously referred material in all other aspects. Cardiocorax mukulu is returned in an early-branching or intermediate position in Elasmosauridae in four out of the six of our phylogenetic analyses. Cardiocorax mukulu lacks the elongated cervical vertebrae that is characteristic of the extremely long-necked elasmosaurines, and the broad skull with and a high number of maxillary teeth (28–40) which is characteristic of Aristonectinae. Currently, the most parsimonious explanation concerning elasmosaurid evolutionary relationships, is that Cardiocorax mukulu represents an older lineage of elasmosaurids in the Maastrichtian.

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Portugal is ranked within the ten countries with more dinosaur taxa and the Lourinhã Formation is known
by the Late Jurassic findings of dinosaurs and other fossils. Often, studies of the external morphological
characteristics of the fossils are not sufficient and, observations of internal structures, using non-
destructive techniques, are required. The fossils here presented belong to the Museum da Lourinhã
(Portugal) and comprise a lower jaw of a basal crocodilian (possibly a Tomistomidae), eggshells and
several vertebrae from the exceptionally well preserved in ovo remains of Late Jurassic theropod dinosaur
Lourinhanosaurus. Neutron Tomography (NT) experiments with this material has been carried out at the
Geesthacht Neutron Facility in Germany. Additionally, eggshell fragments and several vertebrae have
been studied by Synchrotron-Radiation based Micro-Computed Tomography (SRμCT) at the HARWI II and
BW2 beamlines, respectively. These beamlines are operated by the Helmholtz-Zentrum Geesthacht at the
storage ring DORIS III at the Deutsches Elektronen–Synchrotron DESY in Hamburg, Germany. In both cases
(NT and SRμCT) complete 3D recordings have been obtained using a non-destructive procedure. The high-
quality tomographic datasets can be effectively studied through interactive digital visualization. Hence,
these visualization methods provide precious information about the 3D internal micro morphology of
fossils, like the network of the eggshell pores, often invisible in more traditional techniques, and provide a
direct window into the evolutionary history of organisms.