The Dinosaurian Ichnofauna of the Lower Cretaceous (Valanginian–Barremian) Broome Sandstone of the Walmadany Area (James Price Point), Dampier Peninsula, Western Australia

Abstract

Extensive and well-preserved tracksites in the coastally exposed Lower Cretaceous (Valanginian-Barremian) Broome Sandstone of the Dampier Peninsula provide almost the entire fossil record of dinosaurs from the western half of the Australian continent. Tracks near the town of Broome were described in the late 1960s as Megalosauropus broomensis and attributed to a medium-sized theropod trackmaker. Brief reports in the early 1990s suggested the occurrence of at least another nine types of tracks, referable to theropod, sauropod, ornithopod, and thyreophoran trackmakers, at scattered tracksites spread over more than 80 km of coastline north of Broome, potentially representing one of the world's most diverse dinosaurian ichnofaunas. More recently, it has been proposed that this number could be as high as 16 and that the sites are spread over more than 200 km. However, the only substantial research that has been published on these more recent discoveries is a preliminary study of the sauropod tracks and an account of the ways in which the heavy passage of sauropod trackmakers may have shaped the Dampier Peninsula's Early Cretaceous landscape. With the other types of dinosaurian tracks in the Broome Sandstone remaining undescribed, and the full extent and nature of the Dampier Peninsula's dinosaurian tracksites yet to be adequately addressed, the overall scientific significance of the ichnofauna has remained enigmatic.At the request of the area's Goolarabooloo Traditional Custodians, 400C hours of ichnological survey work was undertaken from 2011 to 2016 on the 25 km stretch of coastline in the Yanijarri-Lurujarri section of the Dampier Peninsula, inclusive of the coastline at Walmadany (James Price Point). Forty-eight discrete dinosaurian tracksites were identified in this area, and thousands of tracks were examined and measured in situ and using three-dimensional photogrammetry. Tracksites were concentrated in three main areas along the coast: Yanijarri in the north, Walmadany in the middle, and Kardilakan-Jajal Buru in the south. Lithofacies analysis revealed 16 repeated facies types that occurred in three distinctive lithofacies associations, indicative of an environmental transgression between the distal fluvial to deltaic portions of a large braid plain, with migrating sand bodies and periodic sheet floods. The main dinosaurian track-bearing horizons seem to have been generated between periodic sheet floods that blanketed the preexisting sand bodies within the braid plain portion of a tidally influenced delta, with much of the original, gently undulating topography now preserved over large expanses of the present day intertidal reef system. Of the tracks examined, 150 could be identified and are assignable to a least eleven and possibly as many as 21 different track types: five different types of theropod tracks, at least six types of sauropod tracks, four types of ornithopod tracks, and six types of thyreophoran tracks. Eleven of these track types can formally be assigned or compared to existing or new ichnotaxa,...

Shape variability in tridactyl dinosaur footprints: the significance of size and function

“…These reference marks are not necessarily homologous and thus are not incorporated in the Procrustes superimposition or any of the subsequent geometric morphometric analyses. Coordinates of both the landmarks and reference marks, as well as scaling information, were collected using the freeware tpsDig 2.17 (Rohlf 2014).…”

A multidisciplinary approach to digital mapping of dinosaurian tracksites in the Lower Cretaceous (Valanginian–Barremian) Broome Sandstone of the Dampier Peninsula, Western Australia

“…This is very likely because of the simplicity associated with the ease of point-and-shoot camera operations as the basic means of data collection. As a consequence this approach has been used for track data collection (Thulborn, 1997; Matthews & Breithaupt, 2001; Breithaupt, Matthews & Noble, 2004; Matthews, Noble & Breithaupt, 2006) and documentation (Bates et al, 2008; Petti et al, 2008; Romilio & Salisbury, 2014; Pond et al, 2014; Salisbury et al, 2014), ichnotaxonomic assessments (Pond et al, 2014; Lallensack, Van Heteren & Wings, 2016; Salisbury et al, in press), and for demonstrating track sequence formation (Xing et al, 2015). …”

“…1), with a rich diversity of dinosaurian tracks at tracksites scattered over more than 80 km (Thulborn, Hamley & Foulkes, 1994; Long, 1998; Thulborn, 2012; Salisbury et al, 2014; Salisbury et al, in press). In addition to the scientific importance of the dinosaurian tracks, their recent inclusion in the West Kimberley National Heritage Area (Australian National Heritage List, Place ID 106063) necessitates the need for comprehensive documentation.…”

Peer Review #2 of "The systematic position of the enigmatic thyreophoran dinosaur Paranthodon africanus, and the use of basal exemplifiers in phylogenetic analysis (v0.1)"

“…The aforementioned Isaberrysaura from Patagonia has characteristics of both basal thyreophorans and basal stegosaurs; however, further study and a postcranial description of the skeleton, are needed to elucidate the taxonomic status of the specimen. Stegosaurian ichnofacies are also reported throughout Gondwana, in Western Australia (Salisbury et al, 2016), Southern India (Galton and Ayyasami, 2017), and Bolivia (Apestequía and Gallina, 2011). Additionally, an indeterminate stegosaurian specimen was reported by Haddoumi et al (2016) in Morocco, and there have been repeated reports to a taxon previously referred to as Dravidosaurus in Southern India (Galton and Ayyasami, 2017).…”

“…Manuscript to be reviewed 2013) (although these appear similar to sauropod footprints according to Salisbury et al (2016)) and in the Lower Cretaceous Broome Sandstone of Western Australia (Salisbury et al, 2016), as well as in the Upper Cretaceous of Southern India (Galton and Ayyasami, 2017).…”