Sauropod dinosaur trackways in a Middle Jurassic lagoon on the Isle of Skye, Scotland

Abstract

Synopsis:The Middle Jurassic was a dynamic interval in dinosaur evolution, but the dinosaur fossil record from this time is extremely poor throughout the world. The Isle of Skye (Scotland) preserves marginal marine and terrestrial deposits of Middle Jurassic age, which have yielded sparse bones, teeth, footprints, and small segments of trackways belonging to dinosaurs. We report the discovery of the most extensive dinosaur fossil site yet known in Scotland: a coastal outcrop of the Duntulm Formation (Bathonian) at Cairidh Ghlumaig, Skye, that preserves numerous trackways of sauropod dinosaurs in multiple layers deposited in a lagoonal system. We present an initial description of these tracks and identify them as most likely belonging to a primitive, non-neosauropod species that retained a large claw on manual digit I and produced narrow-gauge trackways. They provide additional evidence that basal sauropods persisted deep into the Middle Jurassic, a time when the earliest members of larger and more derived sauropod lineages were radiating. The new Skye tracks document multiple generations of sauropods living with the lagoonal environments of Jurassic Scotland, and along with other tracks found over the past two decades, suggest that sauropods may have frequented such environments, contrary to their image as land-bound behemoths.

Review of the Dinosaur Remains from the Middle Jurassic of Scotland, UK

“…A large number of eusauropod tracks were found in situ in sediments of the Duntulm Formation at Cairidh Ghulmaig at Duntulm Castle (Figure 4e) [13] and a single footprint was recorded on a loose block at Rubha nam Brathairean in rocks of the Valtos Formation [12]. Similar footprints have also been found in the Valtos Formation near Dùn Dearg in calcareous sandstones on sun cracked surfaces ( Figure 3b) [8].…”

“…Middle Jurassic dinosaurs are becoming better known from Scotland as more discoveries are made each year along the rocky shoreline of the Isle of Skye [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. Studies of the track diversity from the Isle of Skye have shown that there are several different forms of tridactyl prints of varying sizes.…”

“…From small theropod footprints (mostly between 6 and 30 cm in length) [5,7,8] to much larger theropod footprints (about 50 cm long) [6,8] as well as large supposed ornithopod footprints [1,2]. More recently there have been trackways and single footprints of sauropods demonstrating that there existed a diverse dinosaur fauna during the Middle Jurassic of north western Scotland [12,13].…”

New Bathonian (Middle Jurassic) sauropod remains from the Valtos Formation, Isle of Skye, Scotland

“…1). The marine reptile fauna has also generated a lot of interest with research being carried out more recently by the inter-institutional collaborative group: PalAlba (Clark et al 1993, Rees & Underwood 2005, Brusatte et al 2015b.…”

An unusual small-bodied crocodyliform from the Middle Jurassic of Scotland, UK, and potential evidence for an early diversification of advanced neosuchians

“…A scenario depicting the overall environment was presented by Hudson & Trewin (2003). Dinosaur fossils, most notably the trackways of large sauropods, are now known from the lower part of the formation (Brusatte et al 2016), northeast of where NMS G.2016.21.1 was collected.…”