Consumption of crustaceans by megaherbivorous dinosaurs: dietary flexibility and dinosaur life history strategies

Abstract

Large plant-eating dinosaurs are usually presumed to have been strictly herbivorous, because their derived teeth and jaws were capable of processing fibrous plant foods. This inferred feeding behavior offers a generalized view of dinosaur food habits, but rare direct fossil evidence of diet provides more nuanced insights into feeding behavior. Here we describe fossilized feces (coprolites) that demonstrate recurring consumption of crustaceans and rotted wood by large Late Cretaceous dinosaurs. These multi-liter coprolites from the Kaiparowits Formation are primarily composed of comminuted conifer wood tissues that were fungally degraded before ingestion. Thick fragments of laminar crustacean cuticle are scattered within the coprolite contents and suggest that the dinosaurian defecators consumed sizeable crustaceans that sheltered in rotting logs. The diet of decayed wood and crustaceans offered a substantial supply of plant polysaccharides, with added dividends of animal protein and calcium. Nevertheless, it is unlikely that the fossilized fecal residues depict year-round feeding habits. It is more reasonable to infer that these coprolites reflected seasonal dietary shifts—possibly related to the dinosaurs’ oviparous breeding activities. This surprising fossil evidence challenges conventional notions of herbivorous dinosaur diets and reveals a degree of dietary flexibility that is consistent with that of extant herbivorous birds.

Allometric scaling of seed retention time in seed dispersers and its application to estimation of seed dispersal potentials of theropod dinosaurs

“…The estimated mean SRT, however, varied widely according to the model used (simple model or best PGLS model); the best PGLS model, which incorporated food habits, yielded estimates that were approximately three times longer (Table 3). This result and the fact that the food habits and feeding strategies of these dinosaurs remain partly unknown (Chin et al 2017) indicates the uncertainty of our estimates and the clear need for their further refinement. These refinements should involve a deeper understanding of these dinosaurs' lifestyles, as well as further SRT modelling for extant animals with diverse foraging and digestive strategies, particularly for herbivores.…”

Histological evidence for a dynamic dental battery in hadrosaurid dinosaurs

“…Some species, such as Edmontosaurus annectens , had up to 60 tooth families with approximately 300 teeth per dentary 1 , 5 . This complex dental system increased the efficiency of processing tough vegetation, including siliceous phytoliths and the soil attached to low-lying vegetation 8 , 9 , as well as crustaceans 10 .…”

The oldest freshwater crabs: claws on dinosaur bones

“…Beside their proposed systematics assignment, claw shape and important size cannot be used to inform on a specific diet or life habit of the crabs, nor on the actual interactions they could have maintained with reported members of their ecosystem. Interestingly, it is of note stressing that consumption behaviours of decapod crustaceans by megaherbivorous dinosaurs have been reported from the Campanian of two North American formations 92 . In that case, representatives of ankylosaurs, brachylophosaurs and neornithischians were point 350 out to display scattered undetermined crustacean cuticles associated to fragments of likely rotted wood fragments in their in-situ coprolites.…”

“…In that case, representatives of ankylosaurs, brachylophosaurs and neornithischians were point 350 out to display scattered undetermined crustacean cuticles associated to fragments of likely rotted wood fragments in their in-situ coprolites. This led the authors to suggest these crustaceans were consumed when sheltered in dead logs without these cuticles could be identified as belonging to a specific order, although possibly corresponding fossil crab-like claws (not identified as Eubrachyura) were known from surrounding continental middle Campanian formations [92][93][94] .…”