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[dinosaur] Australia: Theropod tracks from Jurassic + Early Cretaceous vertebrate dates




Ben Creisler
bcreisler@gmail.com

Some recent papers for Australian dinosaurs:


Anthony Romilio, Steven W. Salisbury & AndrÃas Jannel (2020)
Footprints of large theropod dinosaurs in the Middle-UpperJurassic (lower Callovian-lower Tithonian) Walloon Coal Measures of southern Queensland, Australia.
Historical Biology (advance online publication)
doi: https://doi.org/10.1080/08912963.2020.1772252
https://www.tandfonline.com/doi/full/10.1080/08912963.2020.1772252


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 photographs. Here, we consolidate data from the literature, present previously unpublished archival photographs, and show the 3D topography of all accessioned track specimens from the Walloon Coal Measures.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 Australiaâs 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.

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Barbara E. Wagstaff, Stephen J. Gallagher, W. Michael Hall, Vera A. Korasidis, Thomas H. Rich, Doris E. Seegets-Villiers & Patricia A. Vickers-Rich (2020)
Palynological-age determination of Early Cretaceous vertebrate-bearing beds along the south Victorian coast of Australia, with implications for the spore-pollen biostratigraphy of the region.
Alcheringa: An Australasian Journal of Palaeontology (advance online publication)
doi: https://doi.org/10.1080/03115518.2020.1754464
https://www.tandfonline.com/doi/full/10.1080/03115518.2020.1754464


Palynology is used to provide new age controls for the coastal exposures yielding Early Cretaceous vertebrate faunas in the Otway and Gippsland basins, southeast Australia. This work shows all vertebrate-bearing deposits in the Otway Basin are Albian in age. On the eastern margin of Cape Otway, vertebrate-bearing deposits are attributed to the early Albian Crybelosporites striatus Zone, except for one in the younger Coptospora paradoxa Zone. To the west of Cape Otway, the sampled deposits range from the oldest zone in the Albian, the C. striatus Zone, to the C. paradoxa and Phimopollenites pannosus zones, providing a complete section of the Albian stage. In the Gippsland Basin, the structural setting of vertebrate deposits is more complicated and large portions of the coastal exposures consist of repeated sections controlled by small-scale faults. Sites in this region lie below or above the Barremian/Aptian boundary. However, owing to the paucity of age indicator species, some sampled deposits remain undated. In this basin, the ranges of certain key palynomorph species (e.g., Pilosisporites notensis and Pilosisporites parvispinosus) differed from those outlined in some previously published biostratigraphic schemes. The discovery of the angiosperm pollen Clavatipollenites hughesii in the lowermost Aptian deposits of the Gippsland Basin is consistent with its first occurrence elsewhere in Australia and shows it is a reliable indicator for the Aptian stage. This study shows that there is currently a collection bias towards vertebrate assemblages that are latest Barremian and early Albian in age.

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