Ankylosaurus Dermal Armor - Scute Fragment
Above: Front of Specimen Card
Covered in rows of bony plates and wielding a powerful clubbed tail, the Ankylosaurs are one of the most distinctive and successful of all dinosaur families. Spread across more than 90 million years of the fossil record, various species of this sturdy dinosaur can be found on every continent on earth.
This specimen is a fragment of an Ankylosaurus dermal plate from the Hell Creek formation in South Dakota. It was recovered by paleontologists working on private land. Large and oval in shape, these "scutes" are consistent with the armor that protected the neck and shoulders of Ankylosaurus from the sharp teeth of predators. Ankylosaurus first appeared in the Third Edition of the Mini Museum. It is also featured in Age of Dinosaurs.
The specimen comes inside a classic, glass-topped riker display case measuring 4 1/2" x 3 1/2". A small information card is also enclosed that also serves as the certificate of authenticity.
Please Note: The fragments vary widely by size and shape. They are roughly 1/2" (2cm) in size.
More about Ankylosaurus
"The armor are bones that form within the skin, just like crocodiles."
~ Ken Carpenter, Director USU Eastern Prehistoric Museum
The plates of an Ankylosaurus were not part of the skeleton, but rather formed within the skin. This type of growth is called an osteoderm. Osteoderms usually begin with small nodules of cartilage around which more dense material forms.
Osteoderms are found in many different and unrelated species from reptiles and amphibians to mammals, fish, and of course dinosaurs. They sometimes form fantastic structures such as the shells of the armadillo and glyptodon, or the tall, dorsal plates and tail spikes of Stegosaurus.
Another interesting aspect of Ankylosaurus's evolution is a progressive widening of the "hindgut" over time. The hindgut is broadly referred to as the lower part of the digestive system. In certain animals, this feature is highly developed, allowing for the extraction of nutrients from cellulose via microbial fermentation. An increase in the size of this feature over time might speak specifically to competitive pressure between different herbivorous dinosaur species such as the ceratopsids and hadrosaurids.
Above: Back of Specimen Card