July 23rd, 2021
This week’s #fossilfriday is the wonderful triangular shaped predentary. This bone makes up the front part of Pachyrhinosaurus lakustai’s lower jaw and connects the 2 lower jaw bones (dentary) by having a grove that allows these bones to fit snuggly into. This bone also would have been covered by a keratin sheath which is the same material that makes up the beaks of modern birds.
The shape of the predentary has important clues to determine what this dinosaur ate. Large robust beaks like this in modern species are often a sign of eating tougher plant material and the narrow point of the predentary also suggests a very specialized or picky diet. These clues point to Pachyrhinosaurus lakustai eating tough fern and cycad fronds where it would use its beak to nip off the frond before chewing. #FossilFriday
A special thank you to our Preparation Lab volunteer Cindy Wendorf for preparing this specimen.