skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.


Title: An asynchronous Mesozoic marine revolution: the Cenozoic intensification of predation on echinoids
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.  more » « less
Award ID(s):
1630276
PAR ID:
10315604
Author(s) / Creator(s):
; ; ; ; ; ;
Date Published:
Journal Name:
Proceedings of the Royal Society B: Biological Sciences
Volume:
288
Issue:
1947
ISSN:
0962-8452
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ABSTRACT Interactions with predators and parasites can result in traces found on Recent and fossil echinoids. However, identifying specific trace makers, particularly on fossil echinoids, remains contentious. To document the range of trace morphologies present on echinoids and improve our ability to identify and quantify biotic interactions affecting echinoids, we characterized traces found on fossil echinoids using museum collections and field sampling spanning the Jurassic to Recent worldwide. Using light microscopy, 8,564 individual echinoid specimens were examined including 130 species, and 516 traces of potential biotic interactions identified. Morphological characteristics were recorded for each trace, including the shape of the trace outline, maximum diameter and cross-section profile. Based on shared morphological characteristics, it was possible to classify all traces into eight categories: circular, subcircular, elongated, irregular, rectangular, figure-eight, notched, and linear. Cross-section characteristics provided additional insights into the identity of potential trace makers. To further evaluate the proposed biotic origins of these traces, trace diversity was examined through time and compared with anticipated ecological trends associated with the diversification of echinoids, and their predators and parasites. Trace diversity increased over time, starting in the late Eocene, coincident with the proliferation of echinoid-drilling gastropods, an indication that biotic interactions intensified through evolutionary time, as predicted by several macroevolutionary hypotheses previously tested using mollusks. The morphological descriptions provided here enhance our understanding of biotic traces on fossil echinoids, and the potential to identify temporal trends in the intensity and diversity of biotic interactions that have affected echinoids throughout their evolutionary history. 
    more » « less
  2. The Plio-Pleistocene regional mass extinction of molluscan fauna of Florida and the US Atlantic coastal plain was followed by a period of rapid origination, resulting in similar modern regional species richness. Predator and prey relationships were impacted by high extinction rates across all taxa. Previous studies have suggested that the extinction is associated with a possible system-wide decline in predation intensity, but data from additional prey species both prior to and after the extinctions are needed to determine how general this pattern may be. We examined predatory trace fossils on turritellid gastropods, a clade which experienced substantial extinction during this time. Overall rates of peeling predation on turritellid gastropods across the extinction boundary decreased – with turritellid species having an average peel-repair frequency of 0.41 in the Plio-Pleistocene compared to a frequency of 0.16 in modern samples. However, in the two surviving lineages, Turritella perexilis and Torcula exoleta, peel-repair frequency was similar in the Plio-Pleistocene samples and in modern samples. Fossil T. perexilis had a peel frequency of 0.26, compared to the modern samples’ peeling frequency of 0.14. Fossil T. perattenuata had a peeling frequency of 0.18, while its descendant, T. exoleta, had a peeling frequency of 0.17. Additionally, the incidence of multiple attacks in modern samples is markedly lower. While a majority (89%) of turritellid species went extinct during this event, most fossil species had higher peel-repair frequencies than fossils of the surviving lineages. In contrast with peeling frequency, the frequency of drilling predation on modern descendants is higher than their fossil ancestors (0.21 vs 0.02 and 0.14 vs. 0.11 for T. exoleta/T. perattenuata and T. perexilis, respectively). Across all species, drilling increased from an average of 0.11 in the Plio-Pleistocene samples to 0.19 in modern samples. These results suggest that as turritellid prey diversity decreased, predators may have adapted to attack surviving species, or these lineages may have become more vulnerable to their predators. 
    more » « less
  3. Drillholes represent one of the clearest lines of evidence for predation of benthic invertebrates in the fossil record and are frequently used as a primary proxy for predation intensity in the fossil record. Drillholes are abundant in the late Cretaceous and Cenozoic, but their occurrence is patchy in older deposits of the Mesozoic. The inconsistent record of drillholes in pre-Cretaceous deposits of Mesozoic age are problematic for interpretations of predation-prey dynamics and adaptive radiations, and the role of taphonomy or diagenesis have not been resolved. Here we present drilling percentages for assemblages of well-preserved shelly benthic invertebrates (mainly comprised of bivalves and rare gastropods) from the upper Norian (Upper Triassic) in northern Italy in order to compare these values with reported drilling percentages from the Carnian San Cassiano Formation, a rare Triassic sedimentary unit that has yielded many drilled fossils. The Norian fossil deposits reported here are comparable to those of the San Cassiano in terms of depositional environment, preservation, and region, and can be reasonably compared to the drilling percentage of fossils from the San Cassiano. The sampled deposits are collected from marly limestone horizons in the Argillite di Riva di Solto in the Southern Italian Alps, deposited in the Lombardian Basin, and which are interbedded with shale units containing well-preserved fish and arthropod fossils, enabling a correlation between paleoecological structure of the shelly benthos and the demersal-pelagic predator diversity. Over four hundred bivalve fossils yielded a drilling percentage of 0.24% (1/406), which is typical for fossil assemblages of this age, but the single occurrence of a drillhole in this study is in marked contrast to the many drilled specimens reported from the San Cassiano Formation deposit in Italy. The drilled specimen (with complete drillhole) was an infaunal bivalve and no incomplete drillholes were observed in other specimens. Thus, drilling percentages for the Triassic are consistently low, but present, suggesting that drilling predation was an ecologically minimal influence to benthic communities and unlikely to have driven the significant ecological changes observed in benthic communities during the Late Triassic. Although drilling predation occurred during the Late Triassic, we present an updated database of specialized durophagous predators (including fishes, sharks, and reptiles) that are likely to have been more ecologically influential on benthic communities during the Norian Stage, fishes in particular. 
    more » « less
  4. Abstract Existing classifications of snout shape within Crocodylia are supported by functional studies, but ecological surveys often reveal a higher than expected diversity of prey items within putatively specialist groups, and research into bite force and predation behaviour does not always reveal significant differences between snout shape groups. The addition of more distantly related crocodyliforms complicates the ecomorphological signal, because these groups often occupy a larger area of morphospace than the crown group alone. Here, we present an expanded classification of snout shapes and diets across Crocodyliformes, bringing together geometric morphometrics, non-hierarchical cluster analyses, phylogenetic analyses, ancestral state reconstructions, ecological surveys of diet, and feeding traces from the fossil record to build and test predictive models for linking snout shape and function across the clade. When applied to living members of the group, these new classifications partition out based on differences in predator body mass and maximal prey size. When applied to fossils, these classifications predict potential prey items and identify possible examples of scavenging. In a phylogenetic context, these ecomorphs reveal differences in dietary strategies and diversity within major crocodyliform clades. Taken together, these patterns suggest that crocodyliform diversity, in terms of both morphology and diet, has been underestimated. 
    more » « less
  5. The Cambrian explosion, one of the most consequential biological revolutions in Earth history, occurred in two phases separated by the Sinsk event, the first major extinction of the Phanerozoic. Trilobite fossil data show that Series 2 strata in the Ross Orogen, Antarctica, and Delamerian Orogen, Australia, record nearly identical and synchronous tectono-sedimentary shifts marking the Sinsk event. These resulted from an abrupt pulse of contractional supracrustal deformation on both continents during thePararaia janeaetrilobite Zone. The Sinsk event extinction was triggered by initial Ross/Delamerian supracrustal contraction along the edge of Gondwana, which caused a cascading series of geodynamic, paleoenvironmental, and biotic changes, including (i) loss of shallow marine carbonate habitats along the Gondwanan margin; (ii) tectonic transformation to extensional tectonics within the Gondwanan interior; (iii) extrusion of the Kalkarindji large igneous province; (iv) release of large volumes of volcanic gasses; and (v) rapid climatic change, including incursions of marine anoxic waters and collapse of shallow marine ecosystems. 
    more » « less