Thursday, July 11, 2013

[PaleoEcology / Paleontology • 2013] Skull Ecomorphology of Megaherbivorous Dinosaurs from the Dinosaur Park Formation (Upper Campanian) of Alberta, Canada | Dinosaurs, Diets and Ecological Niches

Styracosaurus, Euoplocephalus & Gryposaurus 
Herbivorous (plant-eating) Dinosaurs from Alberta,
about 75 million years ago, shows niche partitioning at work. It is likely that dietary differences between each species allowed the habitat to support such a diverse population of herbivores.
Shown are six species including two ceratopsids, two hadrosaurs and two anylosaurs;
Chasmosaurus belli, Lambeosaurus lambei and Styracosaurus albertensis,
Euoplocephalus tutus, Gryposaurus and Panoplosaurus mirus with Styracosaurus in background
illustration: Julius Csotonyi


Megaherbivorous dinosaur coexistence on the Late Cretaceous island continent of Laramidia has long puzzled researchers, owing to the mystery of how so many large herbivores (6–8 sympatric species, in many instances) could coexist on such a small (4–7 million km2) landmass. Various explanations have been put forth, one of which–dietary niche partitioning–forms the focus of this study. Here, we apply traditional morphometric methods to the skulls of megaherbivorous dinosaurs from the Dinosaur Park Formation (upper Campanian) of Alberta to infer the ecomorphology of these animals and to test the niche partitioning hypothesis. We find evidence for niche partitioning not only among contemporaneous ankylosaurs, ceratopsids, and hadrosaurids, but also within these clades at the family and subfamily levels. Consubfamilial ceratopsids and hadrosaurids differ insignificantly in their inferred ecomorphologies, which may explain why they rarely overlap stratigraphically: interspecific competition prevented their coexistence.

Mallon JC, Anderson JS. 2013. Skull Ecomorphology of Megaherbivorous Dinosaurs from the Dinosaur Park Formation (Upper Campanian) of Alberta, Canada. PLoS ONE. 8(7): e67182.

Chasmosaurus & Lambeosaurus | EuoplocephalusGryposaurus Panoplosaurus with Styracosaurus in background

GryposaurusPanoplosaurus mirus and Styracosaurus albertensis in background

Dinosaurs, diets and ecological niches: Study shows recipe for success
A new study by a Canadian Museum of Nature scientist helps answer a long-standing question in palaeontology—how numerous species of large, plant-eating dinosaurs could co-exist successfully over geological time.