Unambiguous gastropod drilling predation has been reported in shells of Cretaceous age onwards. Global data suggest that the drilling intensity shows wide spatial variation throughout the Miocene. ...

Drilling gastropod predation on the lower Miocene gastropod assemblages from Kutch, western India: spatiotemporal implications

The distribution of trace-making organisms in coastal settings is largely controlled by changes in physicochemical parameters, which in turn are a response to different climatic and oceanographic conditions. The trace fossil Macaronichnus and its modern producers are typical of high-energy, siliciclastic foreshore sands in intermediate- to high-latitude settings characterized by cold-water conditions. However, it has been found in Miocene Caribbean deposits of Venezuela, prompting the hypothesis that upwelling of cold, nutrient-rich waters rather than latitude was the main control of its distribution. To test this hypothesis that was solely based on the fossil record, several trenches and sediment peels were made in two high-energy sand beaches having different oceanographic conditions along the Pacific and Caribbean coasts of the Central American Isthmus. As predicted, the burrows were found only in the highly productive waters of the Pacific coast of Costa Rica in connection with upwelling, while they were absent from the warm, oligotrophic waters of the Caribbean coast of Panama. This finding demonstrates that sometimes the past may be a key to the present, providing one of the few documented examples of reverse uniformitarianism.

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The search for an elusive worm in the tropics, the past as a key to the present, and reverse uniformitarianism.

We document and quantify one of the oldest predator–prey interactions between naticid gastropods and molluscan prey, on the basis of drill holes in shells, from the Late Jurassic (Oxfordian) beds of Kutch, western India. Previously, many workers recorded naticid-like drill holes on prey taxa from the Triassic and the Jurassic, but in the absence of associated naticid body fossils, they remained equivocal.
 The present gastropod community is dominated by turritellines (98% of the sample) that form the turritelline-dominated assemblage, and the naticid drilling predation is restricted almost entirely to turritellines among gastropods. Confamilial naticid predation takes place occasionally. Within the bivalve community, corbulids and nuculids are most abundant and are drilled more often than other taxa. These observations indicate that prey selection was opportunistic and based solely on availability. Drilling intensities at both assemblage and lower taxon levels are low. Behavioral stereotypy of naticid predation in some cases is moderately high.
 Turritellines are often the preferred prey of naticid gastropods since the late Early Cretaceous. These two groups form a recurrent association reflecting prey–predator interaction. Here we suggest that both turritellines and naticids evolved during the Jurassic, and the prey–predator interaction between them was established shortly thereafter. Among bivalves, corbulids also became important prey of naticids in the same spatiotemporal framework. Corbulids are older than naticids and first appeared during the Middle Jurassic. After their first encounter with naticids, corbulids evolved conchiolin layers within the valves to resist predation.

Paleoecology of naticid–molluscan prey interaction during the Late Jurassic (Oxfordian) in Kutch, India: evolutionary implications

The study of drilling predation has been largely limited to molluscs. Herein, we report drilling predation on Recent acorn barnacles by gastropods from Chandipur, eastern India. The aspects of pred...

Substrate-controlled naticid gastropod drilling predation on recent barnacles from Chandipur, India and its Palaeontological implications

Naticids and muricids are the main drilling gastropod families that leave a characteristic hole in their shelled prey. Drilling predation can be evaluated along spatial scales, and different latitudinal patterns (equatorward, poleward, mid-latitude peaks or no trend at all) have already been described. For Argentine Patagonia, most studies have analysed muricid predation, but scant information is available on naticid predation. This study provides evidence of predation by the moon snail Notocochlis isabelleana on a thin and fragile burrowing bivalve, Darina solenoides, along the intertidal sandflats at Pozo Salado, San Matias Gulf, in northern Patagonia. To estimate the incidence of predation, articulated specimens of Darina solenoides (N = 432) were randomly collected in the intertidal zone. Drill holes (N = 94) were recorded in shell lengths ranging between 10 and 35 mm. Taking into account previous studies in the region, the intensity of mortality by drilling (22%) constitutes a higher value than expected for this latitude. These results may help explain local patterns in a particular site in northern Patagonia which has been previously identified as an outlier, but further studies aimed at evaluating macrogeographic patterns are necessary for a better understanding of the regional factors that might be governing these predator–prey interactions.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/3EB5A0897064DF2E2381CE9844F5F348/S0025315420000892a.pdf/div-class-title-naticid-drilling-predation-from-tidal-flats-in-northern-patagonia-sw-atlantic-div.pdf

Naticid drilling predation from tidal flats in northern Patagonia, SW Atlantic

Despite an expectation that predation pressure decreases with increasing latitude, studies on latitudinal variation in gastropod drilling predation through space and time have revealed equivocal trends. Here, we study the latitudinal pattern of gastropod drilling predation from the late Early Cretaceous to the Pleistocene based on a new compilation of global data on mollusks mostly from the northern hemisphere. The study finds a mid-latitudinal (i.e., 21–40°) peak in drilling predation intensity during the Miocene (the only time interval with sufficient data from all latitudinal bins), and a possible mid-latitudinal peak during the Cretaceous. For the Eocene, Pliocene, and Pleistocene the middle—and either the lower or higher latitudinal—bins show the highest drilling intensity, therefore suggesting a much flatter latitudinal gradient in drilling predation pattern; the Paleocene and Oligocene lack sufficient data for statistical comparison. The Miocene mid-latitudinal peak remains almost unchanged when analyses are restricted to certain ecological and taxonomic groups. Different abiotic (e.g., temperature) and biotic factors (e.g., generic abundances of the predatory gastropods) alone cannot explain the observed trend. The area of shallow shelf might have played a positive but statistically insignificant role in determining the observed pattern.

Latitudinal patterns of gastropod drilling predation intensity through time

The global marine environment is highly heterogeneous although the nature of heterogeneity can vary spatially. In this study, the nature and extent of spatial heterogeneity of the coastal, marine ecoregions along the Central-Eastern and South-Eastern coast of India (parts of Andhra Pradesh, Pondicherry and Tamil Nadu) was studied, which represent two different – Central-Eastern, and South-Eastern – coastal ecoregions. Several environmental (e.g., salinity, temperature, and nutrients of the ocean water, etc.) and physical (e.g., substrate type, energy condition of the coast) parameters were measured (quantitative as well as semi-quantitative approach) and analysed by using several bivariate and multivariate methods. Our results clearly point out that the Central-Eastern, and South-Eastern marine, coastal ecoregions of India are highly heterogeneous among themselves, and even smaller ecoregions (i.e., sub-ecoregions) within each of these larger ecoregions are also different from each other. Thus, each of these ecoregions is internally highly heterogeneous. In addition, there is no consistent spatio-latitudinal change in the environmental variables along the eastern coast of India.

Nature of spatial heterogeneity of the coastal, marine ecoregions along the eastern coast of India

Studies on biostratinomy of modern molluscs are biogeographically (mostly from the Americas and Europe) and environmentally (mostly from subtropical and temperate carbonate settings) restricted, documenting local variation, while large-scale spatio-environmental patterns from the siliciclastic settings are less understood. Here, 8670 dead bivalve specimens were collected from several sandy, sandy-rock mixed, and sandy-clay mixed beach, and beaches associated with tidal flat and sea-grass habitat. Sampling stations were located along a stretch of about 2500 km covering several ecoregions along the eastern Indian coast, a large-scale, biogeographic pattern in biostratinomy is studied. Each shell was assigned seven grades based on shell damages intensities in reference to seven biostratinomic attributes (shell completeness, surface bioerosion, secondary rounding, abrasion, ligament loss, and external and internal wear); the summation of these values indicate the Total Taphonomic Grade (TTG) of individual specimens. Our results suggest, TTG values do not vary systematically with ecological factors (e.g., body size and shape, shell microstructure, etc.), although environmental (e.g., substrate and energy conditions) factors could play some role (e.g., high energy sandy beaches have higher TTG values); no large-scale biogeographic gradient is observed. Based on the characteristics of damage profiles, a siliciclastic beach taphofacies, common in all locations, is proposed: abrasion is the main damage type, whereas, shell fragmentation or biotic damages are negligible. Based on these, a biostratinomic pathway of shells is inferred: after death, shells are immediately locally transported to the beach, reducing exposure time for biotic damages; on beaches, constant swash and backwash cause external and internal abrasion. These taphofacies and biostratinomic pathway models can be used to identify the biostratinomic conditions of analogous modern and fossil assemblages.

Large-scale spatial biostratinomic patterns along the Eastern Indian coasts: Identification of a generalized siliciclastic beach taphofacies applicable in analogues (paleo)environments

Studies on the large-scale latitudinal patterns of gastropod drilling predation reveal that predation pressure may decrease or increase with increasing latitude, or even show no trend, questioning the generality of any large-scale latitudinal or biogeographic pattern. Here, we analyze the nature of spatio-environmental and latitudinal variation in gastropod drilling along the Indian eastern coast by using 76 samples collected from 39 locations, covering ~2500 km, incorporating several ecoregions, and ~15° latitudinal extents. We find no environmental or latitudinal gradient. In fact, drilling intensity varies highly within the same latitudinal bin, or oceanic sub-basins, or even the same ecoregions. Moreover, different ecoregions with their distinctive biotic and abiotic environmental variables show similar predation intensities. However, one pattern is prevalent: some small infaunal prey taxa, living in the sandy-muddy substrate-which are preferred by the naticid gastropods-are always attacked more frequently over others, indicating taxon and size selectivity by the predators. The result suggests that the biotic and abiotic factors, known to influence drilling predation, determine only the local predation pattern. In the present case, the nature of substrate and prey composition determines the local predation intensity: soft substrate habitats host dominantly small, infaunal prey. Since the degree of spatial variability in drilling intensity within any time bin can be extremely high, sometimes greater than the variability across consecutive time bins, temporal patterns in drilling predation can never be interpreted without having detailed knowledge of the nature of this spatial variability within a time bin.

High biogeographic and latitudinal variability in gastropod drilling predation on molluscs along the eastern Indian coast: Implications on the history of fossil record of drillholes.

Hindolita Chakraborty

Papers

Latitudinal patterns of gastropod drilling predation intensity through time

Nature of spatial heterogeneity of the coastal, marine ecoregions along the eastern coast of India

Large-scale spatial biostratinomic patterns along the Eastern Indian coasts: Identification of a generalized siliciclastic beach taphofacies applicable in analogues (paleo)environments

High biogeographic and latitudinal variability in gastropod drilling predation on molluscs along the eastern Indian coast: Implications on the history of fossil record of drillholes.