219 Paleontology, Diversity, Extinction, Origination (Posters)

Tuesday, 21 October 2025
8:00 AM - 5:30 PM
HBGCC, Hall 1

Preliminary Comparison of Functional Diversity Between Ancient Ordovician and Modern Antarctic Post-Invasion Communities

Paper number: 219-1
Program: Technical Sessions
Time: 8:15 AM – 8:30 AM

Authors

Abstract

Although it is well documented that invasions can fundamentally reorganize species interactions, how this transformation affects functional diversity remains unclear. Paleozoic benthic marine ecosystems are in many ways analogous to the Antarctic today, which is dominated by suspension feeders and detritus based food chains, and lacks durophagous predators. Here, we characterize and compare the functional diversity of shallow marine ecosystems in the Late Ordovician to that of  the modern Antarctic based on a published survey after the invasion of King Crabs. The Late Ordovician Cincinnati Series records a well documented incursion of species into shallow marine systems, referred to as the Richmondian Invasion. Species were assigned three common functional traits (motility, tiering, and feeding mode) to compare the number of functional entities and functional redundancy of the Antarctic community and six Ordovician communities (stratigraphic sequence C2-C7). Preliminary results indicate that the Antarctic community has 620 species, compared to the highest in the Richmondian, which had 453 species, found in the youngest post-invasion community (C7). In contrast, despite having notably more species, there were only 21 functional entities in the Antarctic, compared to 32 in the oldest sequence of the Richmondian Invasion prior to the invasion. The Antarctic community therefore has very high functional redundancy and functional over-redundancy compared to the Ordovician communities. The Antarctic community did not have many functional entities with only one species, which suggests low vulnerability to functional losses. This community did, however, have the smallest number of vulnerable functions with fewer than three species, indicating that there is some protection from functional loss compared to the Ordovician communities. While further analysis is required, comparing the post-invasion Antarctic to the suite of Ordovician communities representing different stages of invasion (e.g., arrival versus establishment) will provide important insight into how modern communities may respond to invasions. To identify which functions are important to sustain natural and human communities alike, we need to understand how functional diversity is affected by invasions.

Geological Society of America Abstracts with Programs. Vol. 57, No. 6

doi: 10.1130/abs/2025AM-414125

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