Barrett

Barrett, The Honors College at Arizona State University proudly showcases the work of undergraduate honors students by sharing this collection exclusively with the ASU community.

Barrett accepts high performing, academically engaged undergraduate students and works with them in collaboration with all of the other academic units at Arizona State University. All Barrett students complete a thesis or creative project which is an opportunity to explore an intellectual interest and produce an original piece of scholarly research. The thesis or creative project is supervised and defended in front of a faculty committee. Students are able to engage with professors who are nationally recognized in their fields and committed to working with honors students. Completing a Barrett thesis or creative project is an opportunity for undergraduate honors students to contribute to the ASU academic community in a meaningful way.

Displaying 1 - 1 of 1
Filtering by

Clear all filters

133820-Thumbnail Image.png

Phylogenetic Assessment of the Genus Steinius (Euprimates; Omomyidae)

Description
The genus Steinius has been determined to be one of the earliest forms of omomyids after being hypothesized to belong in the earliest anaptomorphines dating back to the Eocene. This genus is thought to be one of the ancestors of later omomyids. Other ancestors would include an early omomyid with…

The genus Steinius has been determined to be one of the earliest forms of omomyids after being hypothesized to belong in the earliest anaptomorphines dating back to the Eocene. This genus is thought to be one of the ancestors of later omomyids. Other ancestors would include an early omomyid with characteristics resembling the primitive characteristics of Steinius. There are two sister taxa belonging to this genus, Steinius annectens and Steinius vespertinus. Both taxa appear within the strata at Bighorn Basin in Wyoming, with S. annectens appearing in early forms of stratigraphy compared to S. vespertinus. Specimens of both taxa are also lacking with only jaw fragments and single teeth specimens being known today. Although much of Steinius is unknown, it can be associated with Tarsiiformes, or tarsiers. The specimens in this study consisted of lower jaw fragments that were assessed via a microscope containing a reticle calibrated for tooth measurements. These measurements and visual assessments could be used later in the study to determine the relatedness of both taxa. This thesis provides an assessment on the dental morphological characteristics of the genus Steinius that includes both qualitative and quantitative data. The relationship between both sister taxa of this genus is also discussed in detail with a comparison of the similarities found in both teeth. The results obtained from this evaluation showed that both taxa can be determined to be related. One key difference that was noted, however, is that S. annectens has an average tooth size that is larger than that of S. vespertinus and other early omomyids.
ContributorsLauchnor, Sarah Nicole (Author) / Penkrot, Tonya (Thesis director) / Zack, Shawn (Committee member) / School of Nutrition and Health Promotion (Contributor) / School of Human Evolution and Social Change (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05