Multiple parallel deinonychosaurian trackways from a diverse dinosaur track assemblage of the Lower Cretaceous Dasheng Group of Shandong Province, China

Many newly-discovered dinosaur tracksites have recently been reported from the Lower Cretaceous Dasheng Group of Shandong Province. These are proving valuable as tools for characterizing the fauna in deposits almost devoid of body fossils. Here we report on a new Cretaceous site, the 14th documented in recent years, with multiple track-bearing levels, that adds ∼300 tracks to a growing database. At least two morphotypes tentatively labelled as cf. Menglongpus isp., representing a deinonychosaur, and cf. Tatarornipes isp., representing an avian theropod, add to the list of at least seven named ichnogenera attributed to avian and non-avian theropods reported from the Dasheng Group in Shandong Province. Combined with two sauropodomorph and two ornithopod ichnogenera, and unnamed turtle tracks, the genus-level ichnodiversity (∼14) is one of the highest reported for any Cretaceous unit either regionally in China or globally. The tracks identified as cf. Menglongpus isp. occur in four parallel trackways indicating a group of small didactyl bipeds of inferred deinonychosaurian affinity. Despite the lack of body fossils from the Dasheng Group in Shandong Province, a high diversity of deinonychosaur body fossils is known from the contemporary Jehol Biota from northeastern China. This similarity underscores the importance of the Shandong track assemblage as indicators of regional, tetrapod biodiversity during the Cretaceous

The Evolution of Fangs, Venom, and Mimicry Systems in Blenny Fishes

Venom systems have evolved on multiple occasions across the animal kingdom, and they can act as key adaptations to protect animals from predators. Consequently, venomous animals serve as models for a rich source of mimicry types, as non-venomous species benefit from reductions in predation risk by mimicking the coloration, body shape, and/or movement of toxic counterparts. The frequent evolution of such deceitful imitations provides notable examples of phenotypic convergence and are often invoked as classic exemplars of evolution by natural selection. Here, we investigate the evolution of fangs, venom, and mimetic relationships in reef fishes from the tribe Nemophini (fangblennies). Comparative morphological analyses reveal that enlarged canine teeth (fangs) originated at the base of the Nemophini radiation and have enabled a micropredatory feeding strategy in non-venomous Plagiotremus spp. Subsequently, the evolution of deep anterior grooves and their coupling to venom secretory tissue provide Meiacanthus spp. with toxic venom that they effectively employ for defense. We find that fangblenny venom contains a number of toxic components that have been independently recruited into other animal venoms, some of which cause toxicity via interactions with opioid receptors, and result in a multifunctional biochemical phenotype that exerts potent hypotensive effects. The evolution of fangblenny venom has seemingly led to phenotypic convergence via the formation of a diverse array of mimetic relationships that provide protective (Batesian mimicry) and predatory (aggressive mimicry) benefits to other fishes. Our results further our understanding of how novel morphological and biochemical adaptations stimulate ecological interactions in the natural world

Additional notes on the Mount Morgan dinosaur tracks from the Lower Jurassic (Sinemurian) Razorback beds, Queensland, Australia

In a recent paper, community-held archival material was used to evaluate the palaeo-biology of dinosaur track-makers from the ‘fireclay caverns’ of Mount Morgan. With the ensuing interest, community members disclosed additional photographic documentation of Mount Morgan dinosaur tracks. The described theropodan and ornithischian tracks are consistent with the known Mount Morgan ichnofaunal record, while evidence of Anomoepus track-makers walking with the atypical plantigrade pedal posture has not been previously documented in Australia

A reassessment of large theropod dinosaur tracks from the mid-Cretaceous (late Albian-Cenomanian) Winton Formation of Lark Quarry, central-western Queensland, Australia: A case for mistaken identity

Multivariate analysis is used to differentiate shape variations between ichnites of theropod and ornithopod dinosaurs. Tracks of an alleged theropod cf. Tyrannosauropus from the mid-Cretaceous (late Albian-Cenomanian) Winton Formation of Lark Quarry, central-western Queensland, Australia were examined and foot shape ratios calculated. Multivariate analysis of these shape variables indicates this track-maker was an ornithopod dinosaur. A strong morphological similarity exists between the Lark Quarry ichnites and those of the iguanodontian ichnotaxon Amblydactylus gethingi. Considering the grade of ornithopod this ichnogenus is thought to represent (a non-hadrosaurid styracosternan) and the age and geography of Lark Quarry, we suggest that the track-maker may have been a dinosaur similar to Muttaburrasaurus langdoni. (C) 2010 Elsevier Ltd. All rights reserved

Large dinosaurian tracks from the Upper Cretaceous (Cenomanian-Turonian) portion of the Winton Formation, Lark Quarry, central-western Queensland, Australia: 3D photogrammetric analysis renders the 'stampede trigger' scenario unlikely

The largest dinosaurian tracks at Lark Quarry, central-western Queensland, Australia, were re-examined using revised analytical protocols that incorporate three-dimensional (3D) structure. Comparisons were made with archival photographs, replica specimens (c. 1977) and the in situ tracks (2013) to account for changes to the track surface. Damage caused both during and after the excavation of the tracks was evident, and in cases where the archival photographs and 1970's replicas strongly differ from the in situ tracks, it is apparent that restoration has modified the original track morphology

Footprints of large theropod dinosaurs in the Middle–UpperJurassic (lower Callovian–lower Tithonian) Walloon Coal Measures of southern Queensland, Australia

Dinosaur tracks associated with coal-mines of the Middle to Upper Jurassic (Callovian–Tithonian) Walloon Coal Measures (Clarence–Morton Basin) have been reported on more than any other track-bearing formation in Australia, yet due to the brevity of ichnological information, remain poorly known. All these tracks were found in sediments directly above coal seams in the ceilings of subterranean mines. This style of mining ceased more than a quarter of a century ago, and with many of the original mines having been back-filled or closed, ichnological investigations are restricted to the study of museum specimens and archival photo- graphs. Here, we consolidate data from the literature, present previously unpublished archival photographs, and show the 3D topography of all accessioned track specimens from the Walloon Coal Measures. We recognise eleven track-bearing sites, most of which produced large (length of 30–50 cm) and very large (length greater than 50 cm) sized theropod tracks, including Australia’s largest carnivorous dinosaur footprint (79 cm long). The domination of theropod tracks is unique among Australian dinosaur tracksites. In light of the absence of near coveal body-fossil candidates, the Walloon Coal Measures ichnofaunal assemblages fills significant gaps in our understanding of Australia's Jurassic dinosaur fauna

An unusual dinosaur track assemblage from the Jurassic-Cretaceous boundary, Anning formation, Lufeng Basin, China

Late Jurassic dinosaur track assemblages from China are much less common than those reported from the Lower and Middle Jurassic which are heavily dominated by well-known theropod ichnogenera such as Grallator, Eubrontes, Kayentapus, and a few sauropodomorph and ornithischian ichnotaxa. We here report two tridactyl dinosaur morphotypes from the Lufeng Basin in southern China that most closely resemble Late Jurassic Dinehichnus from North America, a probable gracile ornithopod morphotype, and an unnamed avian morphotype reported from rare occurrences in North America and Europe, which we here name as Tridentigerpes ichnogen. nov., accommodating two ichnospecies T. huasibanleei ichnosp. nov. from the Lufeng Basin, and T. pinuelai ichnosp nov., from Spain. These ichnites re-orient our understanding of Late Jurassic dinosaur track distributions in the Late Jurassic of China, which was previously based in large part on very poor material of presumed theropod affinity. Given the sparse body fossil record from southern China including very fragmentary sauropod remains, the ichnological record of diverse bipedal dinosaurs, suggestive of avian and non-avian dinosaurs and ornithopods, the Anning Formation represents a type 2b deposit where tracks are more common than skeletal remains and indicative of faunas not represented by the body fossil record