Dietary palaeoecology of an Early Cretaceous armoured dinosaur (Ornithischia; Nodosauridae) based on floral analysis of stomach contents

Abstract

The exceptionally well-preserved holotype of the armoured dinosaur Borealopelta markmitchelli (Ornithischia; Nodosauridae) from the Early Cretaceous (Clearwater Formation) of northern Alberta preserves a distinct mass within the abdominal cavity. Fourteen independent criteria (including: co-allochthony, anatomical position, gastroliths) support the interpretation of this mass as ingested stomach contents—a cololite. Palynomorphs in the cololite are a subset of the more diverse external sample. Analysis of the cololite documents well-preserved plant material dominated by leaf tissue (88%), including intact sporangia, leaf cross-sections and cuticle, but also including stems, wood and charcoal. The leaf fraction is dominated (85%) by leptosporangiate ferns (subclass Polypodiidae), with low cycad–cycadophyte (3%) and trace conifer foliage. These data represent the most well-supported and detailed direct evidence of diet in an herbivorous dinosaur. Details of the dietary palaeoecology of this nodosaur are revealed, including: selective feeding on ferns; preferential ingestion of leptosporangiate ferns to the exclusion of Osmundaceae and eusporangiate ferns such as Marattiaceae; and incidental consumption of cycad–cycadophyte and conifer leaves. The presence of significant (6%) charcoal may represent the dietary use of recently burned conifer forest undergoing fern succession, early evidence of a fire succession ecology, as is associated with many modern large herbivores.

Exceptionally simple, rapidly replaced teeth in sauropod dinosaurs demonstrate a novel evolutionary strategy for herbivory in Late Jurassic ecosystems

“…Despite nearly two centuries of study and the discovery of novel tooth forms, our understanding of dinosaur dietary ecologies remains limited compared to other groups, such as mammals [ 1 , 2 ]. Much of what is known relies on osteological comparisons to extant analogues, frequently noted in early discoveries [ 3 ], microwear analyses [ 2 , 4 – 9 ], and the rare preservation of stomach contents [ 10 – 14 ]. The few studies that have applied quantitative methods to the study of dinosaur dentitions have yielded tantalizing insights.…”

Neuroanatomy of the nodosaurid Struthiosaurus austriacus (Dinosauria: Thyreophora) supports potential ecological differentiations within Ankylosauria

“…Whereas nodosaurids and ankylosaurids were lumbering 57 , 58 , heavily armoured 9 , 52 and low-browsing 5 animals, mainly relying on large guts (possibly for fermentation) to digest 53 , nodosaurids possibly preferred coastal or fluvial environments 4 and are suspected for having evolved jaw biomechanics delivering stronger bite forces 7 , 8 (potentially for tougher plant material), and the gut content of a nodosaurid hints to a selective feedings style 5 .Furthermore, the combination of a relatively short cochlear duct 40 , the lack of a floccular recess 13 , 17 , 32 , 40 , a short ASC 40 , less elaborated nasal passages 6 , the obligate absence of a tail club 2 , but thickened osteoderms 9 , 52 in nodosaurids indicate different ecological adaptations in comparison to ankylosaurids. Hence, nodosaurids were possibly less reliant on their sense of hearing, applied a less active style of self-defense and, apparently, occupied different ecological niches than ankylosaurids.…”

“…These globally distributed quadruped herbivores were heavily armoured living fortresses; partly either equipped with a club tail (ankylosaurids 2 ) or a collar of hypertrophied spikes on their neck and shoulders (nodosaurids 3 ). Potential palaeoenvironmental 4 and food preferences 5 , together with features of their nasal passages 6 , jaw mechanics 7 , 8 and osteoderms 9 , may indicate different lifestyles for both groups.…”

On Dinosaur Reconstruction: An Introduction to Important Topics of Paleontology and Dinosaurs

“…Taphonomic data, such as preservation states, burial postures and wedged teeth of carnivores, can provide information on the behavior and species of scavengers [101]. In some cases, stomach contents [102] can also be found on the dinosaur excavations site, offering direct confirmation of the species' diet. Finally, the gastroliths [103] [104] found in sauropod dinosaurs raise discussions about whether they could increase grinding effectiveness by accelerating mechanical food processing and, consequently, increasing energy and nutrient acquisition.…”