CT scans offer new insight into the little-understood Pawpawsaurus: One clue that led the researchers to determine that the sense of smell was Pawpawsaurus’s strongest sense was the large olfactory ratio.
Independent science journalist Sarah Puschmann covered the research of SMU Earth Sciences Professor Louis L. Jacobs in a post on her blog “Armored Dinosaur May Have Relied Most on Sense of Smell.”
A professor in Dedman College‘s Roy M. Huffington Department of Earth Sciences, Jacobs is co-author of a new analysis of the Cretaceous Period dinosaur Pawpawsaurus based on the first CT scans ever taken of the dinosaur’s skull.
A Texas native from what is now Tarrant County, Pawpawsaurus lived 100 million years ago, making its home along the shores of an inland sea that split North America from Texas northward to the Arctic Sea.
The Laser Beats Rock article published July 25, 2016.
Pawpawsaurus campbelli is the prehistoric cousin of the well-known armored dinosaur Ankylosaurus, famous for a hard knobby layer of bone across its back and a football-sized club on its tail.
Jacobs, a world-renowned vertebrate paleontologist, joined SMU’s faculty in 1983 and in 2012 was honored by the 7,200-member Science Teachers Association of Texas with their prestigious Skoog Cup for his significant contributions to advance quality science education.
Jacobs is president of SMU’s Institute for the Study of Earth and Man.
By Sarah Puschmann
Laser Beats Rock
In 1819, the German naturalist Lorenz Oken found something astonishing inside a pterodactyl’s broken skull: petrified mud in the form of the long deceased dinosaur’s brain, so well molded into the crevices as to reveal the brain’s two distinct halves.
This so-called “fossil brain” is one of the first known instances of a cranial endocast, an internal cast of the skull that makes the impressions of the decayed soft tissue visible. For paleoneurologists not lucky enough to uncover a natural endocast, some have opted to slice open skulls and made molds using liquid latex rubber or plaster of Paris.
But cutting open a skull for study isn’t always an option, particularly if it is a holotype, the singular specimen used to define a species for the first time. This is the case for the 100 million year old skull from a dinosaur called Pawpawsaurus campbelli studied by Ariana Paulina-Carabajal of the National Research Council of Argentina (CONICET) and the Institute of Investigations in Biodiversity and the Environment (INIBIOMA) and her team, led by Louis Jacobs.
By CT scanning the skull, it was possible to make important insights about the dinosaur’s olfaction and hearing while leaving the precious holotype intact. Their analysis led the researchers to conclude that smell was the sense Pawpawsaurus most likely relied on most, as reported in the journal PLOS ONE.
This is valuable information, especially because so little is known about this dinosaur. What is known is that the four-legged herbivore most likely had long spines on its shoulders and neck, as was the case for other members of the same family of nodosaurids. It also probable that Pawpawsaurus wasn’t endowed with the knob of bone in its tail characteristic of ankylosaurids, a related dinosaur family, nor did it experience the satisfaction of slamming a club tail against, well, anything. (Was there such a thing as tail envy?)