May 28th, 2021

Picture 1: three π‘ƒπ‘Žπ‘β„Žπ‘¦π‘Ÿβ„Žπ‘–π‘›π‘œπ‘ π‘Žπ‘’π‘Ÿπ‘’π‘  π‘™π‘Žπ‘˜π‘’π‘ π‘‘π‘Žπ‘– dentaries from 3 different individuals, arranged from youngest individual at the top, to oldest and most mature at the bottom. Scale bar is 10 cm long.

For today’s #FossilFriday feast your eyes on these beautiful lower jaws from the ceratopsian dinosaur, π‘ƒπ‘Žπ‘β„Žπ‘¦π‘Ÿβ„Žπ‘–π‘›π‘œπ‘ π‘Žπ‘’π‘Ÿπ‘’π‘  π‘™π‘Žπ‘˜π‘’π‘ π‘‘π‘Žπ‘–, recovered from the local Pipestone Creek Bonebed. The size and shape of these jaws are different because they are from different growth stages in the horned dinosaur’s life. The term used by palaeontologists mentioning the relationship of how bones transformed as animals aged is referred to as ontogeny.

The way these lower jaw bones (dentaries) are arranged, represents a very general idea on the bone development of the extinct animal, from youngest at the top to most mature at the bottom. These lower jaw bones have slots or sockets where teeth use to be housed. The teeth have fallen out from their original sockets. This likely happened after the animals died, during stages of decomposition.

Picture 2: interior view of dentaries, (side view from inside the mouth).
Picture 3: exterior view of dentaries, (side view from outside of the mouth).
Picture 4: highlighted in red on this juvenile skull of π‘ƒπ‘Žπ‘β„Žπ‘¦π‘Ÿβ„Žπ‘–π‘›π‘œπ‘ π‘Žπ‘’π‘Ÿπ‘’π‘  π‘™π‘Žπ‘˜π‘’π‘ π‘‘π‘Žπ‘– is the location of where the youngest jawbone comes from, the lower right side of the animal’s head, (modified from Scott Hartman).
Picture 5: highlighted in red on the more mature skull of π‘ƒπ‘Žπ‘β„Žπ‘¦π‘Ÿβ„Žπ‘–π‘›π‘œπ‘ π‘Žπ‘’π‘Ÿπ‘’π‘  π‘™π‘Žπ‘˜π‘’π‘ π‘‘π‘Žπ‘– is the location of where the more mature jaw bones come from, the lower left side of the animal’s head, (modified from Scott Hartman).
Your browser is out-of-date!

Please update your browser to view this website correctly. Update my browser now

x