Were dinosaurs on their way out before “the great extinction”? Grrl Scientist reviews some new research and concludes yes and no.It gets a little technical:
In short, morphological disparity is a measure of the spectrum of body plans, behaviours, and ecological niches exploited by a group. Such measures can reveal the long-term trajectory of a particular group regardless of whether they had high or low species richness or abundance.
The team’s findings reveal clade-specific disparity patterns, painting a more subtle picture than previously thought. On one hand, both geographic and clade-specific morphological variability declined in large-bodied herbivores, the ceratopsids and hadrosauroids, but on the other hand, no decline in morphological variability was detected in carnivorous dinosaurs, mid-sized herbivores, and some Asian taxa. The authors propose that the decrease of morphological disparity in the ceratopsids and hadrosauroids could be due to their more specialised chewing abilities.