33 D20. Future Leaders in Paleontology

Sunday, 9 October 2022
1:30 PM - 5:30 PM
Mile High Ballroom 3C

EXPLORING ORIGINATION AND EXTINCTION PATTERNS IN EARLY PALEOZOIC ECHINODERMS

Paper number: 33-4
Program: Technical Sessions
Time: 2:15 PM – 2:30 PM

Authors

Abstract

The Paleozoic was a time of great climatic and biotic changes that included several large-scale radiation and extinction events. The Great Ordovician Biodiversification Event (GOBE), Late Ordovician Mass Extinctions (LOME), and the end-Devonian extinctions are three such events that heavily impacted the evolutionary trajectories of life on Earth. Coincident with these biotic events were abiotic events that, in part, drove such radiations and extinctions.

The marine invertebrate record provides a robust platform upon which to test hypotheses of evolutionary dynamics, such as origination and extinction and their relationships to abiotic and biotic forcings. Some invertebrate groups have been studied in more detail than others (e.g., brachiopods). Studies concerning evolutionary dynamics of Paleozoic echinoderms have primarily focused on crinoids, which have been used to estimate the dynamics of the entire echinoderm clade. However, this is likely masking true patterns of diversity throughout this time.

To quantify evolutionary dynamics throughout Paleozoic Echinodermata, we constructed a large dataset of genera from all subclades spanning the Cambrian to Devonian. First and last appearance dates and location data (e.g. formation, basin, country) were collected using a variety of sources, including peer reviewed literature and the Paleobiology Database. Using these data, we calculated diversity, origination, and extinction metrics of echinoderms.

Results indicate several turnover events, with diversity increasing slowly from the Cambrian until the Middle Ordovician. Within the Middle Ordovician, there was a notable two-stepped increase (122.85%) in diversity. Other studies have found that the main pulse of the GOBE is limited to the Darriwilian Age, which this finding corroborates. These patterns of evolution will be further explored in this study, and their abiotic forcings further investigated by plotting geochemical datasets along recovered patterns of evolution, extinction, and diversification.

Geological Society of America Abstracts with Programs. Vol. 54, No. 6

doi: 10.1130/abs/2022AM-380368

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