dinosaur museum

November 2019 Newsletter


November Trivia: The third Thursday of November is the Great American Smokeout. November comes from the Latin “novem” meaning “nine”. It is also National Pomegranate month, National Novel Writing month and the second week in November is National Split Pea Soup week.


Hesperornithoides miessleri
Nickname: Lori (named after volunteer Lori Hockemeyer)

This small three foot long chicken-sized dinosaur was discovered by accident while excavating a much larger dinosaur in the Morrison Formation of Wyoming. The Morrison dates to the late Jurassic period about 155 to 140 million years ago. It is one of the most fossil rich rock layers in North America. If you have ever traveled to southeastern Utah, you may have noticed a greenish-colored rock formation between the red rocks. This green mudstone is part of the Morrison Formation, a distinct rock layer spread across the western United States. It is the oldest winged dinosaur ever found in North America and the smallest dinosaur found in Wyoming. It had long thin arms, long gangly legs and the tail is short for the size of its body. It was probably not a fast runner. Due to the work of the team that discovered it and graduate student Scott Hartman, it is helping researchers better understand the evolutionary relationship between modern birds and dinosaurs. The study is also providing new insight into the origins of flight in birds. Theropods are carnivorous, hallow-boned dinosaurs that had three toes and walked on two feet. They include velociraptors, Tyrannosaurus rex, and the ancestors of modern birds. Lori is a theropod, closely related to velociraptors.

This study shows that avian flight may not have evolved until Late Jurassic or Early Cretaceous periods. Lori has features that are similar to birds, such as a well-developed wishbone, but also those that differ, such as large, bladed teeth. It also had a large sickle-shaped claw on each of its feet. It had a diet of tiny little animals and insects to small mammals and lizards and possibly very small dinosaurs. The team believes it had feathers.

Bill Wahl, the paleontologist who helped find Lori said that some tiny delicate bones were damaged with a shovel while digging for another larger dinosaur. They stopped and collected as much of the tiny bones as possible and spent the next few days searching for more. Evidence at the site suggests Lori would have lived in a wetland-like environment. It probably would have had wing feathers, but they would have been too small for it to fly. A theory some scientists have is that dinosaurs may have evolved feathers and wings before they evolved flight to help them run. They could have helped insulate animals and their developing eggs, been useful for attracting mates, or helped them escape predators by allowing them to propel themselves up trees and other sloped terrain. The study authors feel that the first flying ancestors of birds evolved among ground-dwelling dinosaurs, rather than tree-dwelling dinosaurs that could climb and glide.

Hesperornithoides miessleri was named for the Miessler family on whose land it was found. It went on display Friday, July 12, 2019 at the Wyoming Dinosaur Center. Lori’s discovery was announced at the 2003 annual meeting of the Society of Vertebrate Paleontology. It represents a subadult or adult individual. About 44 percent of its skeleton was uncovered. In 2005 it was placed as a close relative of Sinornithoides.

Education Director
Geri LeBold

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