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1. An asynchronous Mesozoic marine revolution: the Cenozoic intensification of predation on echinoids

   https://doi.org/10.1098/rspb.2021.0400  

   Petsios, Elizabeth; Portell, Roger W.; Farrar, Lyndsey; Tennakoon, Shamindri; Grun, Tobias B.; Kowalewski, Michal; Tyler, Carrie L. (March 2021, Proceedings of the Royal Society B: Biological Sciences)

   Predation traces found on fossilized prey remains can be used to quantify the evolutionary history of biotic interactions. Fossil mollusc shells bearing these types of traces provided key evidence for the rise of predation during the Mesozoic marine revolution (MMR), an event thought to have reorganized global marine ecosystems. However, predation pressure on prey groups other than molluscs has not been explored adequately. Consequently, the ubiquity, tempo and synchronicity of the MMR cannot be thoroughly assessed. Here, we expand the evolutionary record of biotic interactions by compiling and analysing a new comprehensively collected database on drilling predation in Meso-Cenozoic echinoids. Trends in drilling frequency reveal an Eocene rise in drilling predation that postdated echinoid infaunalization and the rise in mollusc-targeted drilling (an iconic MMR event) by approximately 100 Myr. The temporal lag between echinoid infaunalization and the rise in drilling frequencies suggests that the Eocene upsurge in predation did not elicit a coevolutionary or escalatory response. This is consistent with rarity of fossil samples that record high frequency of drilling predation and scarcity of fossil prey recording failed predation events. These results suggest that predation intensification associated with the MMR was asynchronous across marine invertebrate taxa and represented a long and complex process that consisted of multiple uncoordinated steps probably with variable coevolutionary responses. 

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2. Spatial distribution, diversity, and taphonomy of clypeasteroid and spatangoid echinoids of the central Florida Keys

   https://doi.org/10.7717/peerj.14245  

   Grun, Tobias B.; Kowalewski, Michał (January 2022, PeerJ)

   Background Irregular echinoids are ecosystem engineers with diverse functional services. Documenting present-day distribution of those widespread organisms is important for understanding their ecological significance and enhancing our ability to interpret their rich fossil record. Methods This study summarizes SCUBA surveys of clypeasteroid and spatangoid echinoids conducted in 2020 and 2021 along the central part of the Florida Keys. The survey included observations on both live and dead specimens, their distribution, habitat preferences, abundance, and live-dead comparison. Results Echinoids were found at 17 out of 27 examined sites (63%) and occurred across a wide range of habitats including coastal seagrass meadows, subtidal sand and seagrass settings of the Hawk Channel, backreef sands, and fine muddy sands of deeper forereef habitats. The encountered species, both dead and alive, included Clypeaster rosaceus (four sites), Clypeaster subdepressus (five sites), Encope michelini (three sites), Leodia sexiesperforata (eight sites), Meoma ventricosa (nine sites), and Plagiobrissus grandis (four sites). All sites were dominated by one species, but some sites included up to five echinoid species. Live-dead fidelity was high, including a good agreement in species composition of living and dead assemblages, congruence in species rank abundance, and overlapping spatial distribution patterns. This high fidelity may either reflect long-term persistence of local echinoid populations or fragility of echinoid tests that could prevent post-mortem transport and the formation of time-averaged death assemblages. Regardless of causative factors, the live-dead comparisons suggest that irregular echinoid assemblages, from settings that are comparable to the study area, may provide a fossil record with a high spatial and compositional fidelity. The survey of live fauna is consistent with past regional surveys in terms of identity of observed species, their rank abundance, and their spatial distribution patterns. The results suggest that despite increasingly frequent hurricanes, active seasonal fisheries, massive tourism, and urban development, irregular echinoids continue to thrive across a wide range of habitats where they provide diverse ecosystem services by oxygenating sediments, recycling organic matter, supporting commensal organisms, and providing food to predators. Results reported here document the present-day status of local echinoid populations and should serve as a useful reference point for assessing future regional changes in echinoid distribution and abundance. 

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3. Parasitism and host behavior in the context of a changing environment: The Holocene record of the commercially important bivalve Chamelea gallina, northern Italy

   https://doi.org/10.1371/journal.pone.0247790  

   Huntley, John Warren; Scarponi, Daniele (April 2021, PLOS ONE)

   Vermeij, Geerat J. (Ed.)

   Rapid warming and sea-level rise are predicted to be major driving forces in shaping coastal ecosystems and their services in the next century. Though forecasts of the multiple and complex effects of temperature and sea-level rise on ecological interactions suggest negative impacts on parasite diversity, the effect of long term climate change on parasite dynamics is complex and unresolved. Digenean trematodes are complex life cycle parasites that can induce characteristic traces on their bivalve hosts and hold potential to infer parasite host-dynamics through time and space. Previous work has demonstrated a consistent association between sea level rise and increasing prevalence of trematode traces, but a number of fundamental questions remain unanswered about this paleoecological proxy. Here we examine the relationships of host size, shape, and functional morphology with parasite prevalence and abundance, how parasites are distributed across hosts, and how all of these relationships vary through time, using the bivalve Chamelea gallina from a Holocene shallow marine succession in the Po coastal plain. Trematode prevalence increased and decreased in association with the transition from a wave-influenced estuarine system to a wave-dominated deltaic setting. Prevalence and abundance of trematode pits are associated with large host body size, reflecting ontogenetic accumulation of parasites, but temporal trends in median host size do not explain prevalence trends. Ongoing work will test the roles of temperature, salinity, and nutrient availability on trematode parasitism. Parasitized bivalves in one sample were shallower burrowers than their non-parasitized counterparts, suggesting that hosts of trematodes can be more susceptible to their predators, though the effect is ephemeral. Like in living parasite-host systems, trematode-induced malformations are strongly aggregated among hosts, wherein most host individuals harbor very few parasites while a few hosts have many. We interpret trace aggregation to support the assumption that traces are a reliable proxy for trematode parasitism in the fossil record. 

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4. Neogene echinoids of Florida

   Osborn, A. S.; Portell, R. W.; Mooi, R. (July 2020, Bulletin of the Florida Museum of Natural History)

   Forty-three species, and five indeterminate taxa of Florida Neogene echinoids are discussed and their geographic and stratigraphic distributions provided. These include 16 species documented from the Pleistocene, 20 from the Pliocene, and 12 from the Miocene. Eight new species are described: Rhyncholampas meansi n. sp. from the Pleistocene; Fernandezaster whisleri n. sp., Genocidaris oyeni n. sp., and Lovenia kerneri n. sp. from the Pliocene; and Clypeaster petersonorum n. sp., Gagaria hunterae n. sp., Brissopsis hoffmani n. sp., and Abertella carlsoni n. sp. from the Miocene. Additionally, we herein recognize Abertella floridana, from the Sopchoppy Limestone, as a species distinct from Abertella aberti, and provide the first documentation of Echinolampas lycopersicus, Rhyncholampas sabistonensis, and Arbia aldrichi from the fossil record of Florida. We update the taxonomy for all referred species and their known distributions. This document is intended to be a compilation of the entire Neogene echinoid record from Florida, which is now understood to have the most speciose and diverse assemblage of Neogene echinoids in the eastern United States. 

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5. Paleogene Echinoids of Florida

   https://doi.org/10.58782/flmnh.xqds7462  

   Osborn, Adam S; Portell, Roger W; Mooi, Rich (February 2025, Bulletin of the Florida Museum of Natural History)

   Sixty-five species and nine indeterminate taxa of Florida Paleogene echinoids are discussed, and their geographic and stratigraphic distributions provided. These include 49 species documented from the Eocene and 16 from the Oligocene. Ten new species are described: Prionocidaris robertsi n. sp., Rhyncholampas mariannaensis n. sp., Rhyncholampas bao n. sp., Weisbordella inglisensis n. sp., Weisbordella libum n. sp., Durhamella tetrapora n. sp., and Brissus jonesi n. sp. from the Eocene; and Plagiobrissus cassadyi n. sp., Eupatagus dumonti n. sp., and Schizaster carlsoni n. sp. from the Oligocene. We reconsidered subjective junior synonyms of all species and resurrect Neolaganum archerensis, Echinocyamus macneili, and Eupatagus mooreanus. Furthermore, we updated the taxonomy for all included species and their known distributions and provide emended diagnoses for the genera and species of Florida Neolaganidae. In addition, we herein report the occurrence of Porpitella micra in Cretaceous strata of the subsurface of Florida. This remarkable finding makes P. micra the earliest known of all the scutelloids. Echinoids within the Ocala Limestone are placed in five echinoid biozones, which are defined within, these include the Oligopygus phelani, Oligopygus haldemani, Oligopygus wetherbyi, Wythella eldridgei, and Haimea brooksi Zones. This document complements the Neogene (including the Quaternary) fossil echinoid fauna of Florida we published in 2020 and represents a compilation of the known Florida Paleogene echinoid record. The region is currently known to have the most speciose and diverse assemblage of Paleogene echinoids in the United States. 

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