Dinosaur-plant interactions within a Middle Jurassic ecosystem—palynology of the Burniston Bay dinosaur footprint locality, Yorkshire, UK

Abstract

Dinosaur footprints are abundant in the Middle Jurassic Ravenscar Group of North Yorkshire, UK. Footprints are particularly common within the Bathonian Long Nab Member of the Scalby Formation and more so within the socalled 'Burniston footprint bed' at Burniston Bay. The Yorkshire Jurassic is also famous for its exceptional plant macrofossil and spore-pollen assemblages. Here we investigate the spore-pollen record from the dinosaur footprint-bearing successions in order to reconstruct the vegetation and assess possible dinosaur-plant interactions. We also compare the spore-pollen assemblages with the macroflora of the Scalby Ness Plant Bed, which occurs within the same geological member as the Burniston succession. The spore-pollen assemblages are dominated by Deltoidospora spp., the majority of which were probably produced by Coniopteris. Lycophyte spores (including megaspores) are common in the Yorkshire Jurassic, but lycophyte parent plants are extremely poorly represented in the macroflora. Seed ferns, represented by Alisporites spp., are moderately abundant. Conifer pollen assemblages are dominated by Araucariacites australis (probably produced by Brachyphyllum mamillare), Perinopollenites elatoides and Classopollis spp., with additional bisaccate pollen taxa. Abundant Ginkgo huttonii in the macroflora suggests that much of the monosulcate pollen was produced by ginkgoes. The diverse vegetation of the Cleveland Basin presumably represented an attractive food source for herbivorous dinosaurs. The dinosaurs probably gathered at the flood plains for fresh-water and also used the non-vegetated plains and coastline as pathways. Although assigning specific makers to footprints is difficult, it is clear that a range of theropod, ornithopod and sauropod dinosaurs inhabited the area.

The rise of feathered dinosaurs:Kulindadromeus zabaikalicus, the oldest dinosaur with ‘feather-like’ structures

“…Most of the palynomorphs recovered at Kulinda are characterized by wide stratigraphic ranges through both Jurassic and Cretaceous deposits (e.g., Norris, 1965; Cornet, Traverse & McDonald, 1973; Filatoff, 1975; Higgs & Beese, 1986; Ilyina, 1986; Markevich, 1995; Li & Batten, 2004; Pestchevitskaya, 2007; Ribecai, 2007; Markevich & Bugdaeva, 2009; Ercegovac, 2010; Lebedeva & Pestchevitskaya, 2012; Kujau et al, 2013; Zhang et al, 2014; Slater et al, 2018; Shevchuk, Slater & Vajda, 2018). The spore and pollen taxa observed in the Kulinda deposits are reported in Middle Jurassic palynozones that are calibrated to ammonite biozones from marine sections (Ilyina, 1986) and palaeofaunas from continental strata (Starchenko, 2010).…”

An introduction to Jurassic biodiversity and terrestrialenvironments

“…The Middle Jurassic terrestrial deposits of the Yorkshire coast, UK, are discussed in this issue by Slater et al (2018). These sequences are well-known for their exceptional plant macrofossil (e.g.…”

“…Couper 1958;Wellman 2015, 2016). Slater et al (2018) examine palynological assemblages and dinosaur footprint fossils to improve vegetation reconstructions and assess possible dinosaur-plant interactions. The authors hypothesize that the diverse vegetation of the Yorkshire Jurassic represented an attractive food source for herbivorous dinosaurs that gathered on the flood plains for freshwater and also used the non-vegetated plains and coastline as pathways (Palaeobiodiversity and Palaeoenvironments 98(1) Doi: https://doi.org/10.1007/s12549-017-0309-9).…”

A Comparison of the Dinosaur Communities from the Middle Jurassic of the Cleveland (Yorkshire) and Hebrides (Skye) Basins, Based on Their Ichnites

“…Certainly, the 'highlands' do not appear to have been a major physical barrier, since the general lack of much coarse-grained sediment at least in the Cleveland Basin indicates a rather subdued topography (see Section 2). The abundance of plant remains [24], both as in situ erect stems (and rootlet beds) and isolated drifted leaves and trunks [5], indicates a rich source of plant food, both on the alluvial plain and in the hinterland [95]. Thus, migrations from the Cleveland to Hebrides area could have taken place either around the margins of the land masses or over their tops.…”

“…Over 250 plant species have been recorded from the Yorkshire Basin, representing species that lived on the alluvial plain or in the adjacent hinterland. These belong to conifers, ferns, bryophytes, lycopsids, sphenophytes, pteridosperms, Caytoniales, Cycadales, Ginkgoales and Bennettitales [24,95,97,98], while allochthonous floras have been recorded from Skye [99]. The next layer in the food chain may be represented by the small gracile forms, both herbivorous ornithischians (not illustrated in Figure 6) feeding on this flora and carnivorous theropods.…”