The year 2018 in non-avian dinosaur paleontology was eventful. Archosaurs include the only living dinosaur group — birds — and the reptile crocodilians, plus all extinct dinosaurs, extinct crocodilian relatives, and pterosaurs. Archosaur palaeontology is the scientific study of those animals, especially as they existed before the Holocene Epoch began about 11,700 years ago. This article records new taxa of fossil archosaurs of the non-avian variety that have been described during the year 2018, as well as other significant discoveries and events related to paleontology of archosaurs that occurred in the year 2018.
Research A study intending to identify the evolutionary processes that drove the diversification of dinosaur body mass is published by Benson et al. (2018). A study on the impact of geography on the evolutionary radiation of dinosaurs is published by O'Donovan, Meade & Venditti (2018), who note increasing amounts of sympatric speciation as terrestrial space became a limiting factor. A study on the impact of publication history on the estimates of dinosaur diversity patterns through time is published by Tennant, Chiarenza & Baron (2018). A study evaluating the possible influence of cuirassal ventilation and a herbivorous diet on the orientation of the pubis of dinosaurs is published by Macaluso & Tschopp (2018). A study on embryos of extant reptiles and birds, aiming to determine the developmental mechanism underlying the acquisition of the dinosaur-type perforated acetabulum, is published by Egawa et al. (2018). A study on the nesting style and incubation heat source in non-avian dinosaurs as indicated by comparison with extant crocodylians and megapode birds is published by Tanaka et al. (2018). A study on pigment traces in fossilized dinosaur eggshells is published by Wiemann, Yang & Norell (2018), who interpret their findings as indicating that eggshell coloration and pigment pattern originated in nonavian theropod dinosaurs. A study on the nutritional value of plants grown under elevated CO2 levels, evaluating the hypothesis that constraints on sauropod diet quality were driven by Mesozoic CO2 concentration, is published by Gill et al. (2018). Studies evaluating the link between the Carnian Pluvial Event and the explosive diversification of dinosaurs in the early Late Triassic are published by Bernardi et al. (2018) and Benton, Bernardi & Kinsella (2018). A study comparing non-avian dinosaur faunas of Appalachia and Laramidia from the Aptian to Maastrichtian stages of the Cretaceous period is published by Brownstein (2018), who also evaluates dinosaur provincialism and ecology on Appalachia. A study on the bone histology of sauropod dinosaurs and birds, looking for histological correlates indicative of the presence of bird-like air sacs, is published by Lambertz, Bertozzo & Sander (2018). A study on the Middle Jurassic flora from Yorkshire (United Kingdom) as indicated by pollen and spores, and on the possible dinosaur-plant interactions in the area is published by Slater et al. (2018). Description and analysis of insect borings on hadrosaur bones from the late Campanian Cerro del Pueblo Formation (Mexico) is published by Serrano-Brañas, Espinosa-Chávez & Maccracken (2018). A study on the sedimentological and ichnological contexts of Early Jurassic dinosaur tracks and trackways from the Ha Nohana palaeosurface located within the upper Elliot Formation (Lesotho), and on the locomotor dynamics and behaviour of the trackmaker dinosaurs, is published by Rampersadh et al. (2018). New Middle Jurassic dinosaur tracksite, preserving sauropod and theropod tracks, is described from the Lealt Shale Formation (Skye, Scotland, United Kingdom) by dePolo et al. (2018). Large theropod (possibly carcharodontosaurid) and ornithopod (basal hadrosauroid) tracks are described from the Lower Cretaceous Sanbukdong Formation (South Korea) by Lee et al. (2018). A unique association of hadrosaur and therizinosaur tracks is reported from the Late Cretaceous lower Cantwell Formation (Alaska, United States) by Fiorillo et al. (2018). Large theropod and small sauropod tracks are described from the Lower Cretaceous Jingchuan Formation (China) by Lockley et al. (2018), who name a new ichnotaxon Ordexallopus zhanglifui. A study on the small to medium-sized tridactyl theropod tracks from the Upper Jurassic of the Jura Mountains (Switzerland), focusing on the possible variations in footprint shape along trackways, is published by Castanera et al. (2018). Theropod tracks (probably produced by Acrocanthosaurus) are described from the Cretaceous (Albian) De Queen Formation (Arkansas, United States) by Platt et al. (2018). First Cretaceous track morphotype attributable to the non-avian theropod ichnogenus Gigandipus is reported from the Lower Cretaceous Jiaguan Formation (Guizhou, China) by Xing et al. (2018), who name a new ichnospecies Gigandipus chiappei. New dinosaur ootaxon Duovallumoolithus shangdanensis is described on the basis of fossil eggs from the Upper Cretaceous Lijiacun Formation (China) by Zheng et al. (2018). A study on dendroolithid eggs from the Upper Cretaceous Tumiaoling Hill locality (Gaogou Formation; Yunxian, Hubei Province, China) is published by Zhang et al. (2018), who transfer the oospecies "Dendroolithus" tumiaolingensis Zhou, Ren, Xu & Guan (1998) to the genus Placoolithus. Evidence of cuticle preservation on theropod eggshells from the Nanxiong Group in China and the Two Medicine Formation in Montana, United States is presented by Yang et al. (2018). Description of a femur of a young diplodocoid sauropod from the Carnegie Quarry (Upper Jurassic Morrison Formation) at Dinosaur National Monument (United States), showing extensive bite marks on the bone, and a study on the identity and feeding technique of the tracemaker is published by Hone & Chure (2018). A skull of a chasmosaurine ceratopsian, preserving bite traces made by a tyrannosaurid theropod, is described from the Campanian Kirtland Formation (New Mexico, United States) by Dalman & Lucas (2018). A study on the function of denticle shape variation in the teeth of coelurosaurs of various body shapes and sizes is published by Torices et al. (2018). New data on feather anatomy in theropod dinosaurs Sinosauropteryx, Caudipteryx and Anchiornis is presented by Saitta, Gelernter & Vinther (2018). Theropod tracksite discovered in the Maastrichtian Nemegt Formation (Mongolia), preserving tracks of least four different trackmakers, and associated with a distorted foot skeleton of Gallimimus, is described by Lee et al. (2018). Didactyl theropod tracks with similarities to footprints attributed to small deinonychosaurian theropods are described from the Middle Jurassic (Aalenian-Bajocian) Dansirit Formation (Iran) by Xing, Abbassi & Lockley (2018). Parallel trackways indicating a group of small didactyl bipeds of inferred deinonychosaurian affinity are described from the Lower Cretaceous Dasheng Group (China) by Xing et al. (2018). Didactyl tracks attributed to juvenile or diminutive dromaeosaurs are described from the Lower Cretaceous (Aptian) Jinju Formation (South Korea) by Kim et al. (2018), who name a new ichnotaxon Dromaeosauriformipes rarus. Bishop et al. (2018) present predictive equations that may be used to model non-avian theropod locomotion, developed on the basis of a study of extant ground-running birds. A three-part series of papers investigating the architecture of cancellous bone in the main hindlimb bones of theropod dinosaurs, and evaluating its implications for inferring locomotor biomechanics in extinct non-avian theropods, is published by Bishop et al. (2018). A study on the resource partitioning among theropod dinosaurs known from the mid-Cretaceous assemblages from Niger (Gadoufaoua) and Morocco (Kem Kem Beds) as indicated by calcium isotope values from tooth enamel is published by Hassler et al. (2018). A study on the early evolution of the theropod hands and wrists, especially on the transition from five- to four-fingered hands, as indicated by the anatomy of the hands of Coelophysis bauri and Megapnosaurus rhodesiensis is published by Barta, Nesbitt & Norell (2018). A study on the morphological changes that occurred during ontogeny in the postcranial skeleton of Coelophysis bauri and Megapnosaurus rhodesiensis is published by Griffin (2018). A study on the anatomy, phylogenetic relationships, paleobiology and biogeography of members of Ceratosauria is published by Delcourt (2018), who names a new clade Etrigansauria. A study on the pneumatization of a noasaurid vertebra recovered from the Upper Cretaceous Adamantina Formation (Brazil) is published by Brum et al. (2018). Two shed tooth crowns of an abelisaurid theropod are described from the Cenomanian Alcântara Formation by Sales, de Oliveira & Schultz (2018), representing the oldest abelisaurid occurrence from Brazil to date. Paulina-Carabajal & Filippi (2018) reconstruct the endocranial cavity enclosing the brain, cranial nerves, blood vessels and the labyrinth of the inner ear of the holotype specimen of Viavenator exxoni. Description of the osteology of Viavenator exxoni is published by Filippi et al. (2018). Fragmented theropod maxilla from the Upper Cretaceous Presidente Prudente Formation (Brazil), initially thought to be a carcharodontosaurid fossil, is interpreted as more likely to be an abelisaurid fossil by Delcourt & Grillo (2018). A vertebra of a large megalosaurid theropod, as well as large theropod footprints representing two morphotypes, are described from the Upper Jurassic (Kimmeridgian) of Asturias (Spain) by Rauhut et al. (2018). A study on the anatomy and histology of a partial spinosaurid tibia from the Lower Cretaceous Romualdo Formation (Brazil), possessing traits previously only observed in Spinosaurus aegyptiacus and correlated with semi-aquatic habits in many limbed vertebrates, is published by Aureliano et al. (2018). Spinosaurid fossils assigned to a form distinct from Baryonyx, Suchomimus and Sigilmassasaurus are described from the upper Barremian Arcillas de Morella Formation (Spain) by Malafaia et al. (2018). A nearly complete pedal ungual phalanx of an early juvenile specimen of Spinosaurus, representing the smallest known specimen assigned to this genus reported so far, is described from the Cretaceous Kem Kem Beds (Morocco) by Maganuco & Dal Sasso (2018). A study on the floating capabilities of Spinosaurus and other theropods is published by Henderson (2018), who argues that Spinosaurus was not highly specialized for a semi-aquatic mode of life. A study on the anatomy of the skull of Concavenator corcovatus is published by Cuesta et al. (2018). A study on the limb anatomy of Concavenator corcovatus is published by Cuesta, Ortega & Sanz (2018). A review of the fossil record of carcharodontosaurid theropods from the Cretaceous of North Africa, assessing its implications for understanding the distribution and ecological role of members of this group, is published by Candeiro et al. (2018). Description of theropod (including tyrannosauroid, ornithomimosaur and dromaeosaurid) specimens from the Ellisdale site of the Cretaceous Marshalltown Formation (New Jersey, United States) is published by Brownstein (2018). A study on the dietary and habitat preferences of theropod dinosaurs from the Upper Cretaceous Mussentuchit Member of the Cedar Mountain Formation of Utah is published by Frederickson, Engel & Cifelli (2018). Theropod fossils from the Lower Cretaceous (Albian) Santana Formation (Brazil), initially thought to be oviraptorosaur fossils, are reinterpreted as fossils of a member of Megaraptora by Aranciaga Rolando et al. (2018).