Record of Naticid Predation on Scaphopods (Mollusca) from the Latest Maastrichtian of Rajahmundry,India

Drilling predation provides a rare opportunity to study and quantify prey-predator interactions in the fossil record. Records of drilling predation on scaphopod mollusc are rare. Here, we report naticid drilling predation on scaphopods from a “Turritelline-dominated assemblage” (TDA) stratigraphically just below the K-Pg boundary sections in Rajahmundry, India, which was situated in the Southern Hemisphere during that time. Low drilling frequency was found in the present assemblage based on 248 specimens, which was similar to most of the Cretaceous values previously reported. Majority of the specimens of previous studies were reported from higher latitudes in the Northern Hemisphere. Our report extended the palaeobiogeography of naticid predation on scaphopods into the Southern Hemisphere. Size and site stereotypy of drillholes on the scaphopod shell suggested that predatory behavior of naticids was already highly evolved, but evidence of escalation was less clear in scaphopod prey.     

EVIDENCE FROM THE FOSSIL RECORD OF AN ANTIPREDATORY EXAPTATION: CONCHIOLIN LAYERS IN CORBULID BIVALVES

Conchiolin layers, organic-rich laminae, are characteristic of the shells of corbulid bivalves. The retention of these layers, despite their high metabolic cost, throughout the evolutionary history of Corbulidae has prompted the proposal of several adaptive scenarios to explain the origin and maintenance of these layers. The most widely held hypothesis contends that conchiolin layers are an adaptation for inhibiting drilling by predatory naticid gastropods. However, others suggest that the layers are adaptations to retard shell dissolution in waters undersaturated with calcium carbonate or to increase shell strength in the face of durophagous (shell crushing) predators. In this paper, experiments using recent Corbula (Varicorbula) gibba (Olivi) and observations of corbulids' present natural habitat demonstrate the current utility of conchiolin layers for all three functions: retardation of shell dissolution in waters undersaturated in calcium carbonate, increase of mechanical shell strength, and inhibition of drilling by predatory naticid gastropods. Earlier analyses of the extensive history of naticid predator-corbulid prey interactions suggested that conchiolin layers were an adaptation, a feature that promotes fitness and was built by selection for its current role, for deterring naticid predators. Not only are naticid drillholes widespread in fossil and recent corbulid shells, but an unusually large number of incomplete drillholes terminate unsuccessfully at conchiolin layers. In addition, a phylogenetic analysis of the origin of conchiolin layers and its function to deter naticid predators is consistent with a hypothesis of adaptation for this function. However, this hypothesis is rejected by an examination of fossil Jurassic Corbulomima. These oldest corbulids contained conchiolin layers before the evolution of naticid drilling during the Early Cretaceous. Therefore, conchiolin layers appear to be an exaptation, characters evolved for other usages and later “coopted” for their current role, for defense against drilling predators. The layers may in fact be an adaptation to resist durophagous predation.     

Lichen Bioerosion on Fossil Vertebrates from the Cenozoic of Patagonia and Antarctica

Different traces occur on fossil bones and teeth coming from the Early Miocene Gaiman Formation (Patagonia, Argentina). Most traces were attributed to the action of terrestrial and marine predators and scavengers. However, other traces on bones and teeth from this unit and one tooth from the Eocene La Meseta Formation (Antarctica) are attributed to chemical corrosion by lichens in recent times, that is, in a very late diagenetic time. The living lichens and calcium oxalate deposits occurring on the traces and their particular pattern indicates that they were not produced by vegetal roots. The lichens include reproductive structures which allowed a proper determination. A kind of corrosion pattern (Type 1) on bones and teeth from Patagonia is associated to Sarcogyne orbicularis Körber, Verrucaria sp. Schrad, and Buellia aff. punctiformis (Hoff.) Massal. The lichen Aspicilia aff. aquatica produced rounded holes on an Antarctic tooth (Type 2). On the same tooth, the epilithic lichen Caloplaca sp. Th. Fries did not leave any kind of mark on the enameloid.     

Drilling predation on scaphopods and other molluscs from the Upper Cretaceous of Manitoba, Canada

Abundant information on drilling predation upon fossil bivalves, gastropods, and brachiopods has been accumulated during the past several decades, but very little is known about the predation on marine, infaunal carnivorous scaphopods. A survey of over 440 specimens of the scaphopod Dentalium gracile collected from the Upper Cretaceous Millwood Member (Campanian) of the Pierre Shale at a site near Russell, Manitoba displays a drilling percentage of approximately 35%. This figure is higher than previously reported for the scaphopods of similar age elsewhere, but is comparable to or lower than that of the sub-Holocene (34–61%). The difference in drilling percentage among different collections may be taxon-related or affected by the composition and structure of the fossil community. Morphologically, the drill-holes, produced by predatory drilling, are beveled with a countersunk profile of clean sharp edges. The drill-hole inner margin is ovate whereas the outer margin is nearly circular. Among the Manitoba specimens, drill-holes seem to be more common on the lateral side. Presumably due to the lack of effective defense strategy, the prey effectiveness is low (∼3.2%). There is no correlation between drill-hole dimension and scaphopod prey size, indicating that predator size does not correlate with the prey size. Nearly 480 specimens of cephalopods, pelecypods, and gastropods were also collected from the same community. There were only a total of 16 drill-holes on this additional material. Over 400 specimens of the only naticid Euspira obliquata were recovered from the same site and are believed to be the predators of the scaphopods and other molluscs. The low percentage (∼2.5%) of drilling on the abundant gastropod E. obliquata may indicate mistaken or opportunistic attacks by the predator, or that the cannibalism is not common in this community.     

Traces of predation/parasitism recorded in Eocene brachiopods from the Castle Hayne Limestone,North Carolina,USA

Schimmel, M., Kowalewski, M. & Coffey, BP. 2011: Traces of predation/parasitism recorded in Eocene brachiopods from the Castle Hayne Limestone, North Carolina, USA. Lethaia, Vol. 45, pp. 274–289. The Castle Hayne Limestone (Middle Eocene, North Carolina), noted for its diverse macro‐invertebrate fossils, was sampled to assess if Early Cenozoic brachiopods from eastern North America record any traces of biotic interactions. Systematic surveys of two North Carolina quarries yielded 494 brachiopods dominated by one species: Plicatoria wilmingtonensis (Lyell and Sowerby, 1845). Despite subtle variations in taphonomy, taxonomy and drilling patterns, the two sampled quarries are remarkably similar in terms of quantitative and qualitative palaeoecological and taphonomic patterns. In both quarries, brachiopods contain frequent drillholes (24.5% specimens drilled). The majority of drillholes were singular, perpendicular to shell surface and drilled from the outside. Ventral valves were drilled slightly more frequently than dorsal ones, but site‐selectivity in drilhole location was not evident. Larger brachiopods were drilled significantly more frequently than smaller ones. However, drillhole diameter did not correlate with brachiopod size. The drillholes are interpreted as records of ‘live‐live’ biotic interactions, representing either predatory attacks or parasitic infestations or a combination of those two types of interactions. A notable fraction of specimens bear multiple drillholes, which is consistent with either parasitic nature of interactions or frequent failed predatory events. The high drilling frequency reported here reinforces other reports (from other continents and other epochs of the Cenozoic), which suggest that brachiopods may be an important prey or host of drilling organisms in some settings. The number of case studies reporting high frequencies of drilling in brachiopods is still limited and thus insufficient to draw reliable generalizations regarding the causes and consequences of these occasionally intense ecological interactions. □Brachiopods, drilling parasitism, drilling predation, Eocene, North Carolina, taphonomy.     

Three New Ichnogenera of Biting and Gnawing Traces on Reptilian and Mammalian Bones: A Case Study from the Miocene of the Czech Republic

The Ahníkov (Miocene, Czech Republic) site represents a concentration of vertebrate skeletal remains in a swamp setting. Autochthonous bone deposits were strongly altered by sedimentary processes and early diagenesis. Biting and gnawing traces recognized on hard animal tissues (bones, teeth, antlers, turtle thoraces) represent seven recurring morphotypes. The following ichnotaxa are erected: Nihilichnus nihilicus n. igen. et n. isp., Nihilichnus mortalis n. isp., Machichnus regularis n. igen. et n. isp., Machichnus multilineatus n. isp., Machichnus bohemicus n. isp., and Brutalichnus brutalis n. igen. et n. isp. Each kind of bones or similar substrates bears a specific proportion of various bite traces but no observed morphotype is specific for a single substrate. Ethologically, traces of sharpening of teeth are principally different from predation traces. The beavers Steneofiber eseri and Steneofiber depereti, the carnivore Amphicyon sp. and the crocodiles are presumed as the tracemakers.     

Caedichnus,a New Ichnogenus Representing Predatory Attack on the Gastropod Shell Aperture

Predatory traces, in which the tracemaker has damaged the prey animal's skeleton to kill and consume it, have a deep fossil history and have received much scientific attention. Several types of predatory traces have been assigned to ichnotaxa, but one of the most studied predatory traces, the wedge-shaped excision produced as a result of attacks mainly by crustaceans on the apertures of gastropod shells, has yet to be described as an ichnotaxon. We propose the ichnogenus Caedichnus to describe the shell damage produced by aperture peeling behavior. Caedichnus is produced by predators that are unable to crush their prey's shells outright. Depending on the predator's peeling ability and the prey's withdrawal depth within the shell, the trace can extend through several whorls of the shell. Aperture peel attacks may fail, allowing such damage to be repaired by surviving gastropods. Thus, the types of attacks that produce Caedichnus may exert selective pressure on prey to evolve better-defended shells (in the case of gastropods) or to inhabit better-defended shells (in the case of hermit crabs). The identification of these trace fossils will enhance our understanding of how predation influences the morphological, and even behavioral, evolution of prey organisms.     

Predation on freshwater snails in Miocene Lake Steinheim: a trigger for intralacustrine evolution?

Shells of the freshwater gastropods Gyraulus trochiformis (Planorbidae or ramshorn snails) and Bania pseudoglobula (formerly Pseudamnicola, Hydrobiidae) from Miocene Steinheim Basin in SW Germany contain small holes with a mean diameter of 0.8 mm. Analyses of comparable holes are so far unknown from fossil or extant assemblages of freshwater shells. This analysis of the perforated shells suggests that the holes were not formed by post‐depositional or pure taphonomic processes. Instead, they were most likely produced by predators. This analysis widens the means for identification of predation on freshwater snail shells that can be used in other palaeolimnological studies. The co‐occurrence of fish teeth and perforated shells in the studied samples as well as the perforation features suggest that the predator was either barbel or tench fish. The correlation between shell sizes and hole diameters suggests a size relationship between predator and prey that may generally be related to gape‐limited fish predators. The co‐occurrence of perforated shells in these lake sediments with a dominance of large and armoured shells suggest that these larger shells with protuberances and knobs could not be crushed by the gape‐limited fish predators. This analysis is the basis for a hypothesis that the endemic evolution of Gyraulus in Lake Steinheim, with some varied forms of shell thickness and morphology, was triggered by a predator–prey relationship based on adaptations to avoid shell‐breaking predators.     

Durophagous predation on scaphitid ammonoids in the Late Cretaceous Western Interior Seaway of North America

This study is the first to report a trend of predation intensity on scaphitid ammonoids from the Turonian to the Maastrichtian (Late Cretaceous) on the basis of analysis of ventral shell breakage in large samples from the US Western Interior Province. Analysis of 835 adult specimens revealed ventral shell breakage in 50 specimens. In most of the damaged specimens, the breakage occurred in a preferred position at the rear part of the body chamber. Ventral breakage is rare in the Turonian specimens, whereas it is common in the Campanian and Maastrichtian specimens. The shell diameter of adult scaphitid ammonoids tends to increase with time. The position of the breakage and the absence of repairs indicate that the ventral breakage resulted from lethal predation. Based on the incidence of breakage and the size and shape of the breaks, possible predators include fish, reptiles and cephalopods such as Placenticeras, Eutrephoceras and coleoids. Our statistical analysis of ventral shell breakage indicates that the incidence of lethal predation increased in conjunction with an increase in adult shell size, suggesting that the body size of the prey was an important factor in predator–prey interactions. In addition, the predatory damage is more extensive in larger adults.     

Recognizing biotic breakage of the hard clam, Mercenaria mercenaria caused by the stone crab, Menippe mercenaria: An experimental taphonomic approach

The ability to assign lethal traces left on prey to particular durophagous predators enhances our understanding of predation pressure in the fossil record. To determine whether stone crabs (Menippe mercenaria Say 1818) leave diagnostic traces in the act of feeding on hard clams (Mercenaria mercenaria Linnaeus 1758), live clams were offered to crabs in laboratory aquaria over several months and the fragments produced during predation were examined for diagnostic breakage patterns. These fragments were then compared both macroscopically and using scanning electron microscopy to the fracture patterns produced by tumbling clams in a rock tumbler which simulated breakage during transport in the surf zone, and crushing clams using an Instron which simulated breakage resulting from sediment compaction. Fossil specimens of Mercenaria mercenaria were also examined to determine whether the criteria for recognizing predation traces generated experimentally could be recognized. While not all acts of predation produce diagnostic traces, when larger fragments (greater than 50% shell remaining) are produced during feeding, predatory-diagnostic breakage ranges from 70 to 80%. Macroscopic breakage patterns generated during the predation experiments were also present in fossil specimens. Damage caused by abiotic mechanisms (tumbling and crushing) is highly unlikely to be confused with damage produced by this predator.     

Identity and Relative Importance of Egg Predators of Rice Leaffolders (Lepidoptera: Pyralidae)

Field andlaboratory studies on predation of rice leaffolder eggs (i.e., Cnaphalocrocis medinalis (Guenée) and Marasmia patnalis Bradley) were conducted to identify major predator species. Direct observations of predation on field-exposed eggs showed that in two seasons Metioche vittaticollis (Stål) and Anaxipha longipennis (Serville) were the major predators of leaffolder eggs. Together these crickets took the largest part of all eggs consumed during observation (92%) and had the highest ratio of visits with predation to their total observed visits to plants with leaffolder eggs. Furthermore, the activity pattern of the crickets matched best the daily pattern of egg disappearance, and the seasonal trends in their observed visits correlated best with the seasonal trends in egg disappearance. Minor predators feeding on field-exposed rice leaffolder eggs were Ophionea nigrofasciata Schmidt-Goebel, Micraspis sp., and Conocephalus longipennis (de Haan). The latter species was the most commonly observed egg predator, but had a negligible share in the total predation. In petri dish tests the consumption of leaffolder eggs by the predatory crickets M. vittaticollis and A. longipennis was far greater than that of four other predators. Female cricket adults consumed at least 80 eggs per day, and all individuals accepted leaffolder eggs as food. According to daily egg consumption and acceptance rates, the predators ranked as follows: M. vittaticollis, A. longipennis > Micraspis sp. > O. nigrofasciata > Paederus fuscipes Curtis, C. longipennis. Predator ranking according to the ratio of visits with predation to total visits in the field was identical to the ranking based on the egg consumption tests. Due to their large predation potential, predatory crickets will probably play an important role in leaffolder egg predation, even when their densities are low compared to those of other predator species.     

Quantification of invertebrate predation and herbivory in food chains of low complexity

Zooplankton grazing impact on algae, heterotrophic flagellates and bacteria, as well as invertebrate predation on herbivorous zooplankton, were investigated in two sub-Antarctic lakes with extremely simple food chains. The two species of herbivorous zooplankton present in the lakes (the copepods boeckella michaelseni and Pseudoboeckella poppei) exerted substantial grazing pressure on algae. However, the dominant algal species exhibited properties that enabled them to avoid (large size or extruding spines, e.g. Staurastrum sp., Tribonema sp.) or compensate (recruitment from the sediment, Mallomonas sp.) grazing. There are only two potential invertebrate predators on the herbivorous copepods in the two lakes: the copepod Parabroteas sarsi and the diving beetle Lancetes claussi. Vertebrate predators are entirely abscent from sub-Antarctic lakes. Based on our experiments, we estimated that the predators would remove at most about 0.4% of the herbivorous copepods per day, whereas planktivorous fish, if present in the lakes, would have removed 5–17% of the zooplankton each day. Consequently, the invertebrate predators in these high-latitude lakes had only a marginal predation impact compared to the predation pressure on zooplankton in the presence of vertebrate predators in temperate lakes. The study of these simple systems with only two quantitatively functionally important trophic links, suggests that high grazing pressure foreces the algal community towards forms with grazer resistant adaptations such as large size, recruitment from another habitat, and grazer avoidance spines. We propose that due to such adaptations, predictions from food web theory are only partly corroborated, i.e. algal biomass actually increases with increasing productivity, although the grazer community is released from predation. In more species-rich and complex systems, e.g temperate lakes with three functionally important links, such adaptations are likely to be even more important, and, consequently, the observable effects of trophic interactions from top predators on lower trophic levels even more obscured.     

A new species of watering pot shell (Bivalvia: Anomalodesmata: Clavagelloidea) from the Miocene of the Murray Basin,South Australia

Abstract: A new species of penicillid watering pot shell, Kendrickiana coquinacola sp. nov., is described from the middle Miocene (Balcombian) Bryant Creek Formation of the Murray Basin, South Australia. The new species differs from the extant K. veitchi in its smaller size, much shorter posterior tube, fewer tubules in the anterior watering pot structure, absence of the pedal slit, discontinuous dorsolateral bands of pitted muscle scars on the internal surface of the anterior bulb and habit of cementing itself to the shells in its surrounding environment. The fossil record of Kendrickiana is reviewed. The record from the Dry Creek Sands is discounted, while a record for the extant K. veitchi from the earliest Pleistocene of York Peninsula is added. K. coquinacola indicates the highly derived anatomy of the genus evolved over a 10‐Ma period from the late Oligocene through the early Miocene.     

Morphological and ecological shifts in a land snail caused by the impact of an introduced predator

Introduced predators have become major threats to native animal species in oceanic islands. A number of studies have shown that alien predators have caused serious extinctions of island endemics. However, little attention has been paid to the evolutionary impacts of alien predators on native species. The present study shows that predation by black rats, Rattus rattus, has resulted in ecological and morphological changes in the land snail Mandarina anijimana from the island of Anijima in the Ogasawara archipelago. The frequency of empty predated shells has increased over the past 17–19 years in southern areas of the island. The shells of these snails were found to be significantly higher, smaller and darker in the survey in 2006 than in the survey in 1987–1989 performed in central and southern parts of Anijima, where predation by Rattus was serious. M. anijimana were formerly restricted to shallow broad-leaved litter, whereas they are currently found in deep palm litter, where predation pressure from Rattus may be lower. This suggests that increased predation pressure by Rattus has changed the habitat use of M. anijimana. The close association between shell morphology and habitat use of Mandarina species suggests that the habitat shift induced by the predation of Rattus has caused these changes in the shell morphology of M. anijimana over a period of 17–19 years.     

Evidence of predation in Early Cretaceous unionoid bivalves from freshwater sediments in the Cameros Basin,Spain

Here, we present evidence of possible vertebrate predation on freshwater bivalves from the Lower Cretaceous strata of the Cameros Basin (Spain). The described collection contains the largest number of vertebrate‐inflicted shell injuries in freshwater bivalve shells yet reported in the Mesozoic continental record. Several types of shell damage on fossil shells of Protopleurobema numantina (Bivalvia: Unionoida) are described and their respective modes of formation interpreted in the context of morphological attributes of the shell injuries and the inferred tooth morphology of predators that could have inflicted such injuries. Detailed study of these bite marks shows similarities with the well‐documented injuries in the shells of marine molluscs, namely ammonoids, that have likewise been attributed to reptilian predators. The most parsimonious interpretation suggests crocodiles as the vertebrates interacting with the bivalves in the Cameros Basin. □Barremian–Aptian; bite marks; freshwater bivalves; predation; reptile; Unionoida.     

Broken pieces: can variable ecological interactions be deduced from the remains of crab attacks on bivalve shells?

Shell fragmentation patterns that result from attacks by durophagous predators on hard‐shelled marine invertebrates are a rich source of indirect evidence that have proved useful in interpreting predation pressure in the fossil record and recent ecology. The behaviour and effectiveness of predators are known to be variable with respect to prey size. It is less well understood if variable predator–prey interactions are reflected in shell fragmentation patterns. Therefore, we conducted experimental trials to test the behavioural response of a living crab, Carcinus maenas, during successful predatory attacks on the blue mussel Mytilus edulis on two prey size categories. Further, we examined resultant shell fragments to determine whether specific attack behaviours by C. maenas could be successfully deduced from remaining mussel shells. In contrast to previous studies, we observed no significant differences in attack behaviour by the predators attributable to prey size. In most experimental predation events, crabs employed an ad hoc combination of five mechanisms of predation previously described for this species. We identified seven categories of shell breakage in predated mussels, but none of these were unambiguously correlated with specific attack behaviour. Combined attack behaviours may produce shell breakage patterns that have previously been assumed to be attributable to a single behaviour. While specific patterns of shell breakage are clearly attributable to durophagy, the results of this study provide important insights into the limitations of indirect evidence to interpret ecological interactions.     

Effects of microhabitat,time of day,and weather on predation of gypsy moth larvae

Summary Wire cages with different-sized meshes were placed on trunks and around leaves at different heights in oak trees and in forest litter. Gypsy moth, Lymantria dispar, instars II–V tethered with threads were placed in each cage (instars II–III only in leaf cages) as well as outside the cages. Predation of larvae decreased from near ground to mid-crown in trees and was highest in litter and very low on leaves. Predation in litter was not strongly related to cage type, suggesting that small, invertebrate predators were active there, but IV–V instars on trunks were mainly killed by relatively large predators, probably forest mice and shrews. Influences of the time of day and weather on predation were evaluated by observing tethered V–VI instars in litter and on tree trunks hourly. Ants, particularly carpenter ants (Camponotus ferrugineus) and Formica sp., and probably vertebrates, were conspicuous predators in the litter. Ants were most active at lower relative humidities, while other predators were apparently not influenced by humidity. No daily activity rhythms of predation were noted. Invertebrates appear to be important predators of larvae only in the litter whereas vertebrates, such as forest mice and shrews, also readily attack larvae on tree trunks.     

Can Naticid Gastropod Predators Be Identified by the Holes They Drill?

We tested the hypothesis that drillholes made by different species of predatory naticid gastropods can be differentiated by variability in the inner (IBD) and outer borehole diameters (OBD) of the holes they drill. We compared two samples of Mya arenaria that were drilled by different predators, Euspira heros and Neverita duplicata, under experimental conditions. Mean IBD:OBD ratio was significantly greater for holes drilled by Euspira compared to Neverita, indicating that Euspira drills a steeper drillhole than Neverita. We also found consistent differences between the two naticids for slopes of regression lines of IBD on OBD after standardization for predator size and prey size and thickness, with slopes for Euspira being steeper, but results were not statistically significant. However, the range of IBD:OBD ratios was wide and overlapped considerably for each species, which decreases confidence in assignment of individual drillholes to a particular predator species. At least in the case of these two naticid species, interspecific differences in variation of the inner and outer diameters of the holes they drill have limited utility in identifying the maker of individual boring traces in the fossil record.     

Bite traces on dicynodont bones and the early evolution of large terrestrial predators

Nied?wiedzki, G., Gorzelak, P. & Sulej, T. 2010: Bite traces on dicynodont bones and the early evolution of large terrestrial predators. Lethaia, Vol. 44, pp. 87–92. Dicynodont (Synapsida: Anomodontia) bones from the Late Triassic (late Norian/early Rhaetian) of Poland yield characteristic tooth marks that can be attributed to three ichnotaxa (Linichnus serratus, Knethichnus parallelum and Nihilichnus nihilicus). The general shape and dimension of these traces perfectly match the dental morphology of a co‐occurring carnivorous dinosaur. It is therefore concluded that early carnivorous dinosaurs were feeding on dicynodonts. This discovery constitutes one of the oldest evidence of dinosaur predator–prey interaction. It is suggested that an evolutionary increase in the size of dicynodonts across the Late Triassic may have been driven by selection pressure to reach a size refuge from early dinosaur predators. □Bite traces, dicynodonts, dinosaurs, predation, Triassic.     

Reappraising the early evidence of durophagy and drilling predation in the fossil record: implications for escalation and the Cambrian Explosion

The Cambrian Explosion is arguably the most extreme example of a biological radiation preserved in the fossil record, and studies of Cambrian Lagerstätten have facilitated the exploration of many facets of this key evolutionary event. As predation was a major ecological driver behind the Explosion – particularly the radiation of biomineralising metazoans – the evidence for shell crushing (durophagy), drilling and puncturing predation in the Cambrian (and possibly the Ediacaran) is considered. Examples of durophagous predation on biomineralised taxa other than trilobites are apparently rare, reflecting predator preference, taphonomic and sampling biases, or simply lack of documentation. The oldest known example of durophagy is shell damage on the problematic taxon Mobergella holsti from the early Cambrian (possibly Terreneuvian) of Sweden. Using functional morphology to identify (or perhaps misidentify) durophagous predators is discussed, with emphasis on the toolkit used by Cambrian arthropods, specifically the radiodontan oral cone and the frontal and gnathobasic appendages of various taxa. Records of drill holes and possible puncture holes in Cambrian shells are mostly on brachiopods, but the lack of prey diversity may represent either a true biological signal or a result of various biases. The oldest drilled Cambrian shells occur in a variety of Terreneuvian‐aged taxa, but specimens of the ubiquitous Ediacaran shelly fossil Cloudina also show putative drilling traces. Knowledge on Cambrian shell drillers is sorely lacking and there is little evidence or consensus concerning the taxonomic groups that made the holes, which often leads to the suggestion of an unknown ‘soft bodied driller’. Useful methodologies for deciphering the identities and capabilities of shell drillers are outlined. Evidence for puncture holes in Cambrian shelly taxa is rare. Such holes are more jagged than drill holes and possibly made by a Cambrian ‘puncher’. The Cambrian arthropod Yohoia may have used its frontal appendages in a jack‐knifing manner, similar to Recent stomatopod crustaceans, to strike and puncture shells rapidly. Finally, Cambrian durophagous and shell‐drilling predation is considered in the context of escalation – an evolutionary process that, amongst other scenarios, involves predators (and other ‘enemies’) as the predominant agents of natural selection. The rapid increase in diversity and abundance of biomineralised shells during the early Cambrian is often attributed to escalation: enemies placed selective pressure on prey, forcing phenotypic responses in prey and, by extension, in predator groups over time. Unfortunately, few case studies illustrate long‐term patterns in shelly fossil morphologies that may reflect the influence of predation throughout the Cambrian. More studies on phenotypic change in hard‐shelled lineages are needed to convincingly illustrate escalation and the responses of prey during the Cambrian.