Wyoming’s smallest dinosaur is a new raptor-like species

By: Peat Bakke

Thermopolis, Wyoming – The Wyoming Dinosaur Center (WDC) announces the opening of a new permanent exhibit showcasing a new raptor-like dinosaur species. Scientifically
named Hesperornithoides miessleri (Heś-per-orn-ih-THOID-ees MEESE-ler-eye)—but informally known as “Lori”—this new dinosaur is slightly less than three feet long and is the smallest dinosaur found so far in Wyoming. The new exhibit will open Friday, July 12 th , and will display the actual fossil bones along with a full-size reproduction of Lori’s
skeleton.

Paleontologists discovered Lori in the summer of 2001, in the Morrison Formation near Douglas, Wyoming, slightly above the excavation site of “Jimbo,” the WDC’s well-
known Supersaurus specimen, which is the largest, most complete dinosaur found so far in Wyoming. The Morrison dates to the late Jurassic period, approximately 155 to 140
million years ago.

Lori is considered a troodontid (tro-oh-DONT-id). Troodontids are a group of meat-eating dinosaurs known to possess sickle-like killing claws and to have potential for
above-average intelligence. They are closely related to the well-known velociraptors, famous for their chilling appearance in the movie Jurassic Park. ​Lori is a pocket-sized
version of its infamous cousins, complete with the killing claw on each foot.

“Lori is the earliest troodontid yet found in North America and was found while removing a ledge of rock at the Jimbo site,” according to WDC paleontologist Bill Wahl, a member of the six-person research team that has just published the most recent assessment of Lori in the online science journal PeerJ. “We spotted the delicate bones poking out and over a few days collected all we could find. Only after cleaning some of the bones did we realize that we had found something spectacular,” notes Wahl.

As a troodontid, Lori is considered a close relative to birds and important to understanding the origins of bird flight. Using sophisticated computer programs, Lori’s
features were compared to those of hundreds of other dinosaur specimens to determine Lori’s place in the dinosaur-bird evolutionary tree. This work was led by team member
Scott Hartman, a Ph.D. candidate at the University of Wisconsin. “We found that Lori is a primitive member of the group of dinosaurs that includes Troodon’” says Hartman,
“and perhaps more importantly that the smaller details of the family tree of bird-like dinosaurs aren’t quite as resolved as some researchers would claim. Within the group of
winged, but non-flying, dinosaurs, we need more testing to hash out the inter-relationships.”

The Lori and Jimbo specimens were found on property owned by the Miessler (MEESÉ–ler) family of Douglas, who donated both to the non-profit Big Horn Basin
Foundation. In 2016, the Foundation merged with the newly organized and now nonprofit Wyoming Dinosaur Center, bringing both specimens under the WDC banner.

“Lori is an amazing discovery and the Meissler family’s generosity ensures that she will remain in Wyoming on display and be accessible for continued research,” comments
Jessica Lippincott, a member of the research team and Education Director at the WDC.

“Along with Jimbo,” adds Lippincott, “she will be a major exhibit in the new museum wehope to build.”

Other research team members include: Mickey Mortimer, paleontologist and researcher in dinosaur classification; Dean Lomax, paleontologist and instructor at the
University of Manchester, England; and Dr. David Lovelace, geologist at the University of Wisconsin Geology Museum in Madison. Lori will be displayed close to the Center’s Microraptor fossil and to the famous Archaeopteryx (“Ark-ee-OP-ter-icks”) specimen, both small dinosaurs with feathers.

The Wyoming Dinosaur Center, Inc. is a nonprofit 501c (3) organization that provides educational experiences for visitors of all ages, promotes research, and conserves Wyoming’s fossil treasures for future generations to study and enjoy.