#  Jared Richards Thesis Defense (Javier Ortega-Hernández, Advisor) 

 



    ![Jared Richards](/sites/g/files/omnuum6811/files/styles/hwp_5_4__480x385/public/oeb/files/jared_richards500_0.jpeg?itok=7oqEzJAI) 

 



 

####  calendar\_today Date and Time 

 **May 5, 2026** 

 10:00AM - 11:00AM EDT 

####  pin\_drop Location 

 **Biological Laboratories 1080**  



 

 



 

**Title:** The Marine Biosphere during the Great Ordovician Biodiversification Event — Quantitative insights from the Early Ordovician Fezouata Shale biota of Morocco

**Abstract:** The Great Ordovician Biodiversification Event (GOBE) consisted of a series of evolutionary radiations at low taxonomic levels amongst major animal clades that increased net biodiversity, morphological disparity, and ecological complexity throughout the Ordovician Period (485 – 444 Ma) relative to the preceding Cambrian Period (539 – 485 Ma). Despite its vital role in the emergence of modern-style marine ecosystems, the Ordovician biosphere is primarily perceived through the conventional fossil record (e.g., shells, teeth, and bones). This "shelly" fossil record provides a limited and heavily biased picture of past biodiversity, as most components of marine macrofaunas today (ca. 80%) are entirely soft-bodied. A much more accurate understanding of the taxonomic diversity, abundance, and ecological complexity within ancient ecosystems can be gained from the study of *Lagerstätten* (singular *Lagerstätte*), as these rare fossiliferous strata preserve the remains of both soft-bodied and shelly organisms. The Fezouata Shale biota (ca. 480 – 475 Ma) from Morocco is one of the only Ordovician deposits with exceptional fossil preservation and an abundant, high-quality assemblage of non-biomineralizing and biomineralizing taxa. The Fezouata Shale includes both Cambrian holdovers, such as radiodonts, lobopodians, and trilobites, as well as representatives of the new Paleozoic faunas, such as echinoderms, mollusks, and brachiopods, making this Early Ordovician deposit both an evolutionary museum and an evolutionary cradle. Additionally, the Fezouata Shale biota provides the earliest fossil evidence of several animal groups, including xiphosurans, crinoids, and asterozoans. Despite its opportune stratigraphic age and high-quality preservation, little is known about the Early Ordovician’s true biodiversity, ecological structure, and complexity, as well as its broader significance to our understanding of the GOBE.

Taking advantage of the rare spatiotemporal context provided by this Early Ordovician *Lagerstätte*, I have assembled an ambitious interdisciplinary thesis following an increasing scale of ecological and spatiotemporal organization. Uniting conventional phylogenetic and descriptive methods with complex functional ecological analysis in **Chapters I and II**, I contextualize the evolutionary significance of a new suspension-feeding lobopodian from the Fezouata Shale and explore the broader macroecology of suspension-feeding lobopodians. In **Chapters III and IV**, I reconstruct this remarkable fossil biota's community and ecological organization and determine how representative the Fezouata Shale faunas are of the Early Ordovician biosphere. In **Chapter V**, I conduct a literature review of reported diversity patterns and synthesize this information to better disaggregate the ebbs and flows of biodiversity across the wider Ordovician.

**Committee:** Javier Ortega-Hernández (Advisor), Stephanie Pierce (Chair), Andrew Davies, Peter Girguis



 

 



 

 See also:- [ OEB Thesis Seminar ](/event-type/oeb-thesis-seminar)
 
 

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