An Investigation Into Predation, Mortality and Taphonomic Bias In

Examensarbete vid Institutionen för geovetenskaper Degree Project at the Department of Earth Sciences ISSN 1650-6553 Nr 384

An Investigation into Predation, Mortality and Taphonomic Bias in the Population Distribution of Neptunea contraria from the Red Crag of East Anglia Påverkan av predation, dödlighet och tafonomi hos Neptunea contraria från Red Crag, England

Alexander Seale

INSTITUTIONEN FÖR

GEOVETENSKAPER

DEPARTMENT OF EARTH SCIENCES

Examensarbete vid Institutionen för geovetenskaper Degree Project at the Department of Earth Sciences ISSN 1650-6553 Nr 384

Alexander Seale

ISSN 1650-6553

An Investigation into Predation, Mortality and Taphonomic Bias in the Population Distribution of Neptunea contraria from the Red Crag of East Anglia Alexander Seale

Predation is a key factor in evolutionary dynamics. It disrupts the potential of fossilisation in prey items and is poorly recorded in the fossil record; failed predation in conical marine gastropods is recorded in scars. Quantifying the scar distribution and collection and taphonomic biases present in the fossil record of the gastropod Neptunea contraria, of the Red Crag Formation, Gelasian, Pleistocene, UK is necessary to approach this dynamic. Neptunea contraria is highly abundant in the Red Crag Formation which is easily accessed. The size and scarring on a large number (450+) of individuals was collected, recorded and measured from pre-existing and new material. The size distribution of Neptunea contraria is non- normal and is enriched in larger individuals, the scar distribution – expected to be Poisson – is not so. Taphonomic and Collection bias had a large influence over the size and scar distributions of Neptunea contraria. Material from the same localities shows very different size distributions. The lack of Poisson distribution suggests different rates of unsuccessful predation over life history of Neptunea contraria, assuming the data is valid.

Keywords: Predation, taphonomy, sampling bias, palaeobiology, gastropods, population distribution

Degree Project E1 in Earth Science, 1GV025, 30 credits Supervisor: Graham Budd Department of Earth Sciences, Uppsala University, Villavägen 16, SE-752 36 Uppsala (www.geo.uu.se)

ISSN 1650-6553, Examensarbete vid Institutionen för geovetenskaper, No. 384, 2016

The whole document is available at www.diva-portal.org

Populärvetenskaplig sammanfattning

Påverkan av predation, dödlighet och tafonomi hos Neptunea contraria från Red Crag, England Alexander Seale

Predation anses vara en viktig faktor inom ekologi och evolution men till vilken grad har effekterna av predation förändrats genom geologisk tid? Det centrala fokuset i denna studie ligger i att frambringa en förståelse av både population- och predationsfördelningen bland marina snäckor av arten Neptunea contraria av Pleistocen ålder från Red Crag-formationen, East Anglia, Storbritannien. Framgångsrik predation resulterar i förstörelsen av snigeln och dess livshistoria registreras i deras skal. Misslyckad predation bevaras i skalen bland individer som överlevt genom ärrbildningar. Det finns ett okänt samband mellan misslyckad och framgångsrik predation. Samlingen av fossilt material från Sedgwick-museet i Cambridge, Storbritannien, ligger till grund för denna studie. Detta material är ofullständigt (d.v.s. material saknas) och noterbart fragmenterat vilket orsakats av nedbrytande processer, därav tafonomi. Denna studie belyser flertalet källor som ger upphov till ett ofullständigt fossilt register, därav processer direkt relaterade till fossilisering och antropogen insamling. Genom att jämföra flertalet uppsättningar av fossilt material som insamlats av olika personer så kan graden av bias i förhållande till insamlingen undersökas. Resultatet av denna studie visar att samlingen av fossila sniglar som för närvarande finns på Sedgwick-museet är ofullständig. Detta är ett tillstånd som uppkommit delvis på grund av inkomplett insamling. Fördelningen av ärr orsakade av misslyckad predation förväntades följa en poissonfördelning. Denna förutsägelse motsägs sannerligen av nuvarande data. Troligtvis har detta förorsakats av en låg ”misslyckad predationsfrekvens”, vilket antyder att graden av predation inte är konstant. Sniglar av en större storlek saknar ärr på den övre delen av sina skal, vilket tyder på att frekvensen av misslyckad predation var låg i de juvenila stadierna. (Översättning: Mohammed Bazzi)

Nyckelord: Predation, tafonomi, provtagning snedhet, paleobiologi, snäckor, populationsfördelning

Examensarbete E1 i geovetenskap, 1GV025, 30 hp Handledare: Graham Budd Institutionen för geovetenskaper, Uppsala universitet, Villavägen 16, 752 36 Uppsala (www.geo.uu.se)

ISSN 1650-6553, Examensarbete vid Institutionen för geovetenskaper, Nr 384, 2016

Hela publikationen finns tillgänglig på www.diva-portal.org

Table of Contents

1. Introduction 1

1.1. Distribution of Scars 2

1.2. Biases 4

2. Aims 5

3. Background 6

3.1. Geological and Ecological Background 6

3.2. Previous work 7

3.2.1. Previous work on transfer of living to fossil population 7

3.2.2. Previous work on taphonomic biases 8

3.2.3. Previous work on collection 11

3.2.4. Previous work on failed predation scars in marine gastropods 13

4. Methodology 14

4.1. Previous Collections 14

4.2. Fieldwork Collection 14

4.3. Collection Strategy 14

4.4. Measurements 16

4.5. Glycimeris Collection 16

4.6. Statistical Methods 18

5. Results 19

5.1. General Results 19

5.2. Size distribution 19

5.3. Scar-frequency Distributions 27

6. Discussion 31

6.1. Methodology 31

6.2. Bias 31

6.2.1. Taphonomic bias 31

6.2.2. Collection bias 32

6.3. Scar frequency distribution 34 Table of Contents (cont.)

6.3.1. Unsuccessful predation 34

7. Conclusion 36

8. Acknowledgements 37

Appendix 1. χ2 Test Calculation 43

Appendix 2. Calculation Data Tables 44

Appendix 3. Data Tables 54

Appendix 4. Supplementary Data Presentation 68

Appendix 5. Supplementary Photographs 69 1. Introduction

The intention of this project is to assess the magnitude and incidence of predation in a single species within a single time period of 400kyr (Head 1998) of the fossil record, in order to test assumptions regarding the impact of predation as a driving mechanism in evolution. To do this it is also necessary to assess the magnitude of biases, both taphonomic and collection, for the specific species. Fossil populations provide a good basis for studying patterns in evolution (Smith 2009). The aims of this study are firstly to look at evidence predation in the fossil record; and secondly to examine the biases which occur within museum collections and within the fossil record. This study will compare museum collection size distributions and structure with those of a new field collection.

Predation has been assumed to be an important factor in evolutionary radiation and population control (Vermeij 1987, Hairston et al. 1960) and in driving evolutionary radiations within the geological record itself. In order to better understand the magnitude of this factor and the intensity of predation in the geological past, it is first necessary to be able to recognise the levels of predation that have occurred. This can be complicated because successful predation is unlikely to leave remains amenable to fossilisation: hard parts are disarticulated during by predation strategies which greatly reduces the probability of fossilisation (Brett and Thomka 2013). Some specific predation strategies manifest this problem to a lesser extent and make preservation is more likely, thus enabling a fossil record of them. Forms of predation that have an increased likelihood to lead to successful fossilisation include boring and drilling by naticid gastropods and peeling carried out by brachyuran decapods – durophagous crabs – on coiled gastropods when unsuccessful. Boring and peeling predation strategies do not guarantee preservation, but do increase the likelihood of preservation of evidence of predation. A count of the abundance of predators does not give an accurate picture of predation intensity due to the ecologically lower abundance and poor preservation potential of predators (Leighton 2002). Gastropods conveniently have their life history recorded by their shells. In the peeling method of attack on gastropods (Bertness & Cunningham 1981), durophagous crabs use the dactyl surface of the claw to remove pieces of the shell from the gastropod aperture margin (see Figure 1, Keen & Coan 1971). Should the crab be interrupted before it can reach the mantle of the gastropod, which retreats as far into the posterior of the shell as possible during an attack, then the gastropod will survive. Subsequently the surviving gastropod may be able to repair the injury and leave a prominent interruption and indentation (see Figure 1) in the whorl; this forms a characteristic scar (Alexander and Dietl 2003).

1cm 2cm

Figure 1, after Keen & Coan (1971) Descriptive illustration of external features of gastropod shell, Examples of Neptunea contraria highlighting in red a scar; from own fieldwork

The assumption is that the recoverable information of unsuccessful predation frequency correlates with the unrecoverable information of successful predation frequency in some significant fashion (Vermeij 1982b). If shells were preserved that clearly showed evidence of successful predation, then the ratio of success to failure would be easily calculated, but shells showing this are rare in the fossil record despite occurring in Recent sediments (Vermeij 1982c). This might be explained by the pull of the recent.. Successful durophagy tend to result in the disarticulation of the prey item (Vermeij 1987, Oji et al. 2003), therefore the observed record consists of individuals that were never successfully attacked. As a result of this loss of victims of predation from the fossil record, the shells that are preserved are clearly a biased sample of the population as a whole. It is assumed that size and age correlate pseudo-linearly and Neptunea contraria, like other large gastropods, shows minimal senescence after the early juvenile period. The fossil record is clearly not a complete representation of the former living community. The question is, then: to what degree does the fossil record represent the living population? This record is biased by various influences other than predation, which must be accounted for. The recorded distribution is unlikely to exactly reflect the incidence of unsuccessful predation in the living community. The factors that cause this alteration of the distribution of scars can be divided into factors that occur during the life of an individual and factors that occur post-mortem. The first set of factors depends on the variability in the non-predatory death rate over the ontogeny of an individual and the age structure of the living population (neither of which will be perfectly reflected in the fossil record), i.e. ecological factors or “ecological sorting”. The second set consists of hydrodynamic, taphonomic or preservation biases and collection bias.

Figure 2 Possible fates of individual Neptunea, After Ishikawa et al. (2004). Each arrow represents a possible or likely source of bias relative to the living population.

1.1. Distribution of Scars Observation of shell scars gives evidence of failed predation. If it is observed that a population has a low incidence of traces of failed predation, then distinguishing a very low rate of predation with a high rate of survival from a very high rate of predation with a low rate of survival, can be very difficult. An informed judgment might be made by quantifying the shell morphology – morphologies which are known to allow higher predation survival rates include thickened aperture margin, dental ornament and external sculpture whereas planispiral shells are known to be vulnerable to attack (Vermeij 1982c). A further assumption is that the presence of a scar does not adversely affect the ability of the individual to resist further predation, Blundon and Vermeij (1983) found that the shell strength of Littorina irrorata is not notably affected by the presence of a repair scar, this premise is taken to be true for Neptunea contraria.

The problem of post-mortem disarticulation is minimised for gastropods such as Neptunea contraria since there is only a single hard part to begin with – the operculum and radula not being preserved. The intention is only to measure the complete individuals. Thus the problems raised in obtaining an accurate count of the given population (Gillinsky & Bennington 1994) are minimised, as the observable number of parts relate in a fashion to the true number of individuals. Comparing the incidence of non-fatal damage to the shells between size classes, allows a comparison of the magnitude of predation in both that size class and the selective pressure between size classes (Vermeij 1982c).

1.2. Biases The question of sampling and its accuracy is raised by Dunhill et al. (2012): the importance of accessibility of outcrops is shown to have a strong effect on both the recorded diversity and species abundance, as is worker effort. In studies which looked at other intervals, the evidence for worker sampling bias was less strong according to (Wignall & Benton 1999) and the fossil record found to be good quality; the amount of worker influence fossil record correctness is uncertain. Understanding the relationship between an observable population of fossil specimens and the once living population that is represented by those fossils is highly relevant since it allows us to be able to gauge the distribution of predation in that population. The size distribution of living mollusc and gastropod populations that are well sampled is overwhelmingly pyramidal with >80% annual mortality being reported (Gosselin & Qian 1997). Most individuals of a species at any one time will be juvenile or sub-adult (Ruggiero et al. 1994). This is not the case for fossil populations, which tend to have a normal distribution (Fagerstrom 1964) in collection based studies. This reason for the difference needs to be taken in to account when discussing fossil populations. Neptunea contraria would be expected to have a survivorship curve similar to living members of the buccinid group, which have a Type III survivorship curve (Shimoyama 1985).

2. Aims This report will aim to characterise the distribution of these failed predation scars in the buccinid gastropod Neptunea contraria var. angulata (Vervoenen et al. 2014), from the Red Crag Formation, Lower Pleistocene/Upper Pliocene, East Anglia, England, with the view of eventually understanding better how this relates to broader patterns of predation and mortality. This report will attempt to clarify the extent of collection biases in the record by comparing the size- frequency distribution of pre-existing collections to a field collection intended to be unbiased, to examine the influence of size-selective taphonomic breakage by comparing size cohorts and to compare the size-frequency distribution of broken and whole shells. The level of size-selectivity and the degree of size-selective preservation will be assessed by using size cohorts within the population to look at the difference in scar-frequency distribution between those sizes (Budd pers. comm. 2016.). It is taken that size and age correlate pseudo-linearly and Neptunea contraria, like other large gastropods, shows minimal senescence after the early juvenile period. Part of the purpose of this report is to investigate the scale of some of these sources of bias, the arrows from Figure 2 i.e. Collection – collection bias and from Burial – taphonomic bias. The null hypothesis concerning the size-frequency distribution is that there will be a normally distributed data accounting for collection bias. Collection bias is expected to generate a non-normal and positive skewed data i.e. an enrichment in larger individuals. The null hypothesis concerning the scar distribution, is that there will be a Poisson distribution of scars; that is to say they are discrete, low-frequency events with a random time interval and no influence on subsequent event probability.

3. Background

3.1. Geological and Ecological Background The Red Crag is a series of marine deposits at the Piacenzian (Upper Pliocene) and lower Gelasian (base of the Pleistocene) of East Anglia (see Figure 3). The Formation is comprised of coarse, cross- bedded abundantly fossiliferous red sands with interfingered finer sands which grade into coarse- medium-fine sands that are inversely graded. The base is glauconitic with reworked litho- and bio- clasts. This represent a warm (Head 1998) – “Mediterranean”, high-energy and shallow environment. The maximum thickness is 70m, thinning to the North-West. The contact is unconformable with the Upper Eocene. Reworked litho- and bio- clasts are common in the lower ~3m of the section. Based on foraminiferal records, the Formation shallows upwards from the littoral to sub-tidal regimes (Zalasiewicz et al. 1988). Figure 3 shows a geological map of East Anglia, Figure 7 shows a detailed geological map of the area included in this report. According to the most recent systematics (Vervoenen et al. 2014), numerous sub-specific variants of the Pliocene species Neptunea angulata are synonymous with respect to themselves, and are ancestral to the modern species Neptunea contraria. Through this report they are referred to as Neptunea contraria.

Figure 3 – Geological Map of East Anglia, taken from http://www.bgs.ac.uk/research/ukgeology/regionalGeology/home.html

3.2. Previous work

3.2.1. Previous work on transfer of living to fossil population In this section; those factors that result in size-selective biases during life will be addressed. The factors that may be considered are the variability in the non-predatory death rate over the ontogeny of an individual and the age structure(s) of the living population.

In the marine environment there are many fates that can befall a shell (see Figure 2) such as destruction by bioerosion or mechanical abrasion. Use by hermit crabs, Paguroidea, is another fate that can occur (Ishikawa et al. 2004). There will not be any regrowth of damage to a shell then occupied by hermit crab, however some proportion of shells which are undamaged will be salvaged by hermit crabs, where they are then exposed to potential durophagy and suffer disarticulation. This can skew the signal of the non-predatory death rate of the gastropod population Therefore some amount of the shells which would otherwise be available to the fossil record are disarticulated and lost owing to the activities of hermit crabs.

Failed predation scars are not equivalent to drill bores in the shells of marine gastropods: since the successful attack of durophagous crabs these are assumed to entirely disarticulate the prey when the shell is crushed and therefore leave no trace, the trace being one of repair not attack Drill bores may still leave evidence in the shell when the attack is successful. “Just because one has a favourite food does not mean one can eat it every day” (Leighton 2002). A size cohort that is more vulnerable to predation may show fewer predation attempts owing to its low abundance relative to a less vulnerable but more common size cohort; though this is less applicable to this model and study since that looked at difference between species. Optimal foraging strategy is presented by various authors such as (Leighton 2002) as a null model for predator strategy. In this sequential model the value of a prey to a predator equals the 𝑒𝑒𝑔𝑔−𝑒𝑒𝑐𝑐 opportunity cost: benefit ratio. Favourable prey is takenℎ to always be attacked; less favourable prey to never be attacked. Thus the scar rate is dependent on the frequency of encounter, λ, and the probability of a successful attack, ps. For a single species the value can be expected to change over the 𝑒𝑒𝑔𝑔−𝑒𝑒𝑐𝑐 ontogeny and with the size of the organism, which provides theℎ theoretical basis for a differential rate of failed predation between size bins (Vermeij 1982c). The scar frequency distribution changes over time, or size (Vermeij 1987) can be accounted for by four variables:

1. Number of predators/ number of prey 2. Prey defense effectiveness/predator ability 3. Size bias 4. Predator preference/ critical size

A quantification of the extent of size selective biases has been performed by Cooper et al. (2006). They find that the effect was significant, with 79% of total losses attributed to size– the remainder to fragility and rareness; but they also find that this can be reduced if exhaustive techniques are employed in soft sediments. This size bias had been noted with respect to living and recent communities (Kidwell 2001 amongst others (Cooper et al. 2006) focus on poorly lithified material, of similar compaction to the Red Crag Formation. A relationship where smaller individuals are not found in present collections is definitively found by the methodology of Cooper et al. (2006): c. 50% of small individuals (0.5 to <5 mm) not present. The explanation of this phenomenon is not done, however it is the purpose of this investigation to attempt to do so. Whether this rule is applicable in a general sense, to gastropods might be questioned; furthermore the methodology depends on a close comparison of the distribution of living: fossil specimens. Vermeij (1976) and also Leighton (2002,) highlight the concept of critical size or predation refuge that is to say the relevant prey species occupies a behavioural or morphological niche in which

8 its predator is unable or unwilling to successfully attack it and therefore does not attempt to do so resulting in no observed scars. This observation of = 0 can result if predation = 1 and if = 0.

The null hypothesis is that there will be a Poisson𝑓𝑓 distribution of scars: that the𝑝𝑝 scar forming 𝑝𝑝events are discrete, low-frequency events with a random time interval and no influence on the probability subsequent events. This idea is supported by the findings of Suzuki et al. (2002) which showed there was no size-dependence of mortality if the modern species Neptunea arthritica in individuals with an Apex-aperture length >4cm. The possible effect of post-mortem predation by crabs on shells which were utilised by hermit crabs (Ishikawa 2004) or by crabs with a mistaken identity, unable to tell if the shell contains living individual (Walker & Yamada 1993) has an effect on the record of successful predation in gastropods. Firstly, successful marks are not indicative of success even when found, secondly some percentage of otherwise complete individuals otherwise available to enter the fossil record are removed even when not destroyed by predation during life. Whilst this distribution is often mirrored by similar distributions amongst living organisms, the causes behind normal distributions in living communities and death assemblages must come about through different means.

3.2.2. Previous work on taphonomic biases Taphonomy, deriving from the Greek τάφος, meaning burial, is the study of the process of decay and fossilisation. The process of fossilisation is selective, which results in biases in the fossil record (Wilson 1988). When looking at collections, small individuals will not be as well represented, and data concerning them will become less reliable regardless of the reasons being either sampling and collection or non-preservation (Valentine et al. 2006). A main cause of this in taphonomic processes is that thinner shelled, small individuals are likely to be destroyed by physical abrasion (Kidwell & Bosence 1991). The problems of depth and geographic range influencing taphonomy (Valentine et al. 2006) are not relevant to this study which covers a restricted geographical and temporal section. Given a pool of disarticulated individuals, it can be asked how many whole assemblages that number will represent. Gilinsky & Bennington (1994) show that the relationship between “true” individuals and disarticulated body parts to be a function of the size of the sampling domain, with larger sampling domains showing a closer agreement between the number of disarticulated body parts and the “true” number of individuals.

How does the durability of an animal’s hard parts affect the likelihood of it occurring in the fossil record? Irrespective of the time averaging which produces the fossilisable population, it could be expected that more durable shells will be less damaged and have a higher probability of preservation. Since shell strength is proportional to thickness squared (Vermeij 1986) this would lead to a greater proportion of larger individuals. However an extensive series of tests failed to show support for durability having an effect on preservation, apart for mineralogy which is not relevant to this investigation (Behrensmeyer et al. 2005). It follows that the taphonomic effect of shell durability is low or non-existent and that the size frequency information is controlled by some other biological or collection factor. Time averaging of a community does not result in alterations of the relative abundance of species; nor between intraspecific size classes. Sensitivity to collection biases via mesh size choice, naturally relevant for microfossils and fragmentary material is observed by several authors (Kidwell 2001). Predators are believed to be important agents of selection, by causing evolutionary adaptions in their prey species. Predators are clearly not 100% effective although the causes of failure are not always obvious. 100% efficiency will not show so well in the fossil record, and not at all in this investigation, which looks at a method which is only visible in failure (Vermeij 1982c). Durophagous crabs have been reported, in modern experiments, to have a wide range of predation success efficiencies of 9% – 65% (Vermeij 1982b, Hadlock 1980). If the target in question has a morphology which is known to promote survival, such a highly coiled shell or a thickened lip-margin,

Figure 4 Schematic representation of the taphonomic expectation that durable taxa are more common than less durable taxa. Adapted from Behrensmeyer et al. (2005). then the likelihood if the observed scars correlating to the real number of attacks is high since successful attacks are presumably rarer (Vermeij 1982c). Populations with low numbers of juvenile or young individuals may result from spatial separation (Cadée 1982), or selective predation, either way is hard to differentiate. The real problem is the poor preservation of small i.e. juvenile individuals 10

(Olson 1957). This makes analysing both questions - the varying non-predatory death rate with size and the varying preservation with size - difficult to assess. Recent studies show that the risk of predation for juveniles decreased rapidly with increasing body size (Griffiths & Gosselin 2008). In high energy environments compositional fidelity is low, small specimens are winnowed and taphonomic process control the size-frequency distribution (Tomasovych 2004). In low energy environments population structure has a greater control on the size-frequency distribution in the fossil record. Whether smaller individuals have better preservation than larger individuals is contrasted by Tomasovych (2004) and Copper et al. (2006). Smaller individuals are characterized by better preservation than larger, commonly broken individuals (Tomasovych 2004). Small shells generally are more delicate and therefore are more readily damaged by taphonomic processes (Cooper et al. 2006). This report will attempt to distinguish between those views.

3.2.3. Previous work on collection A particular subset of taphonomic biases of interest here are those which occur due to human collection: to the first order this would be expected to be significant. The degree to which human collection impacts diversity reports and size sampling has been investigated to some extent. It has been suggested that there is a correlation between worker effort in collecting and apparent diversity (Dunhill et al. 2012). This is relevant to this investigation as the same effect presumably applies to size. Furthermore there is the effect of species rich locations being worked on more extensively, making the whole Formation seem richer than it is otherwise. This may apply to size distribution as well: areas with more visible larger specimens are more likely to be worked on – distorting the true picture. The published fossil record of species diversity is under-reported relative to the total collected diversity, by a factor of 5 for gastropods (Koch 1978) using exhaustive sampling, it follows that the collected species diversity is less than the total species diversity. This principle is equally applicable to size-distribution; the collected record does not fairly represent the total record. Ignoring fragmentary material leads to an incomplete understanding of the general fossil record (Donovan 1996). This applies to disarticulated material from single element skeletons as well as discrete parts of multi element skeletons. Hunter & Donovan (2005) find that there is no explanation for the absence of some crinoid groups in the Maastrichtian Mons basin other than non-collection. Rarity is not a persuasive argument for non-identification given the large amount of material. Lack of sedimentological information in unsorted and unlabelled material necessarily prevents determination of any environmental gradients which may affect a distribution of species diversity or of scar frequency distribution. There is an overprinting of true ecological signal by collection bias. Echinoderms from three European basins, which are an easily disarticulated and can be systematically ambiguous i.e. asteroids and crinoids were found to be undercollected (Hunter &

Donovan 2005). That study noted that otherwise fragmentary groups were well represented when they had been intensively studied by other authors. Mesh size choice is a possible source of collection bias; previously studies show larger mesh size results in significantly more correlation between living and dead populations, in recent sediments (Kidwell 2001). This is explained by that author to be due to both ecological and taphonomic reasons. The overwhelming majority of small (juvenile) individuals die before they become large (adult) ones; and they are largely not included within the fossil assemblage. Larger individuals have a high probability of being preserved in the fossil assemblage owing to their durability. In living nearshore communities, small individuals are noted to be overwhelmingly more easily transported or dissolved (Aller 1995, Kidwell 2001) Modern molluscan assemblages show the highest correlation between dead and living populations, therefore the sum of ecological and/or taphonomic biases must be low, among recent benthic organisms. These results result from highly random censuses, so are unlikely to have collection biases (Kidwell and Flessa 1995). Good agreement between the population structures of living and dead communities, due to a low degree of taphonomic selection, is well supported in the live:dead studies by Kidwell and Flessa (1995). The natural range of the size distribution is apparent from time–averaged assemblages. They do not represent an instantaneous picture of the living community even before accounting for selective fossilisation. These records are assumed to offer a good picture of morphological and size-frequency variation. The death assemblage should be biased numerically toward species that are short-lived and/or taphonomic robust – as gastropod macro- and micro- structure is. Even better correlation has been achieved if biomass rather than individual counts is used (Kidwell 2001). Considerable doubt has been raised by some authors as to whether the observed size-frequency distribution from the fossil record is a function of original biological factors; or whether it is a result a purely secondary process (Olson 1957). In order to extract meaningful information on the fossil history of predation, the record needs to reflect the community structure of the fossil population to at least a certain degree. A unimodal distribution is the expected pattern. Bimodality is to be only expected in the event of an event-bed or instantaneous deposition; or a strongly seasonal deposition. Bimodal distributions are rarely present; this is a transient condition which is actually infrequently found (Cummings et al. 1987). Time-averaged assemblages show the species' abundance well (Kidwell 2001). As Cummings et al. (1987) propose, the size-frequency distribution of fossil assemblages is an indication of taphonomic, though not necessarily population, dynamics. The size- frequency distribution of that data of recent molluscs is dominated by taphonomic selectivity rather than ecological information.

3.2.4. Previous work on failed predation scars in marine gastropods Studies relating to failed predation scars have previously been undertaken. These include the survival advantage of left-handedness (Dietl & Hendricks 2006), and the magnitude and structure of the Mesozoic marine revolution in the benthic community (Vermeij 1977). Lindström & Peel (2005) look at the relative influence of factors in determining the susceptibility of different shells forms to attack. There have also been investigations on the predation of gastropods by specific predators; however this study is only looking at the prey item – Neptunea contraria – and without reference to a specific predator.

4. Methodology

4.1. Previous Collections In order to assess the size frequency and scar frequency distributions of Neptunea contraria data was gathered from pre-existing collections. There are three pre-existing collections that were used. These are the Philips Cambridge collection, the Cannon & Brookes collection; both housed in the Sedgwick Museum, Cambridge, England. Thirdly the unsorted material also held at the Sedgwick Museum formed the last collection, referred to in the text as the Unsorted Sedgwick collection.

The Philips Cambridge and Cannon & Brookes material are not sorted and do not have locality data or specimen numbers. The Sedgwick Unsorted material also lacks locality data. All of the collection are assumed to be from throughout the vertical and lateral sections of the Red Crag. From each collection the entire available material was used.

4.2. Fieldwork Collection A fourth, new collection was made for this study in order have additional data to assess the size frequency and scar frequency distributions of Neptunea contraria and also in particular to assess the extent of collection bias in the pre-existing collections. The fieldwork was carried out between 21/2/2016 and 24/2/2016 at the localities in Figures 5 – grid references and 6 – locality map. Figure 7 shows the the local geology proximate to the localities.

4.3. Collection Strategy At each locality the following sampling strategy was used: samples were taken at spacings of 3m horizontally, and 1.5m vertically (were the section was more than 1.5m vertical and within the limits of accessibility on cliff sections). At each sampling point sufficient material was taken to fill a 3.5cm x 2.5cm sampling bag. Washing was done off locality. Samples were excavated from the unconsolidated material using shovels.

Name Grid Reference

Walton-on-the-Naze (see Figure 51°51'49.64"-52'19.89"N 1°17'38.86"E 9)

Buckanay Farm (see Figure 10) 52° 1'47.86"N 1°26'0.55"E

Butley (Broom Covert) 52° 5'31.69"N 1°27'11.86"E

Ramsholt 52° 1'40.12"N 1°21'28.94"E

Waldringfield Heath (Quarry) 52° 3'23.81"N 1°17'31.87"E

Bawdsey Cliff 51° 59'51.39"52° 0'6.67"N 1°25'4.63"-28.67"E

Neutral Farm Pit 52° 6'25.20"N 1°27'43.13"E

Figure 5 The locations of the fieldwork areas Fieldwork was carried between 21/2/2016 and 24/2/2016.

Figure 6 Locality Maps, East Anglia, England showing areas marked for field work collection of samples Retrieved from Google Earth

Localities

10km

Figure 7 – Locality Maps, East Anglia, England showing areas marked for field work collection of samples Retrieved from http://mapapps.bgs.ac.uk/geologyofbritain/home.html. Localities marked as yellow dots: see Figure 6

4.4. Measurements The material collected was washed and sorted. Fragments and complete individuals were then characterised. Two measurements per shell were taken: from the apex to the aperture of the siphonal canal, tangentially to the widest point of the shell; and the distance from the apex to the aperture around the length of the whorls. Scars, when found, were measured as the distance around the whorl from the apex and aperture. The total length is necessarily approximated, since the last few millimetres of the apex are almost always broken.

4.5. Glycimeris Collection To enable a better comparison of the collection of this investigation and the existing collection, and to correct for relative biases between them – especially collection bias, collection of Glycimeris glycimeris was also done (see Figure 8 for an example of the morphology of Glycimeris). Additionally, were the abundance of Neptunea to be too low to enable a good comparison, then Glycimeris could be compared with to resolve biases. These are more abundant than Neptunea contraria in the Crag, so

16 allow a better understanding of collection bias induced variability in the size-frequency distribution. These were collected and sorted in the same manner as Neptunea. Measurements were taken of the height and length of each valve. See Photo 3 on the next page. These can be compared only to the Philips Cambridge collection, the others not containing sufficient numbers of Glycimeris glycimeris.

4cm

Figure 8 – Glycimeris glycimeris, Ramsholt River Cliff, Suffolk, dimension parallel to the hinge line is length, perpendicular to the hinge line is height from http://www.nmr-pics.nl/glycymerididae_new2/album/slides/PLIOCENE- RED%20CRAG%20FORMATION%20Glycymeris%20glycymeris.jpg

Figure 9 Walton-on-the-Naze cliff outcrop at 51°51'49.64" 1°17'38.86"E, retrieved from http://www.discoveringfossils.co.uk/walton_on_naze_fossils.htm

Figure 10 Bucknay Farm Pit outcrop at 52° 1'47.86"N 1°26'0.55"E, own photograph

4.6. Statistical Methods In order to reject or confirm if the scar-frequency distribution of Neptunea contraria corresponded to the null hypothesis of a Poisson distribution a χ2 test was used. This test procedure was appropriate since the sampling method was simple-random and the variables are categorical. This is done by defining the log-likelihood function L(λ) based on the length-dependent Poisson distribution (1). Then finding the value of λ that maximises the likelihood (2). Therefore the best value of λ is simply the total number of scars divided by the total length of all shells added together. Based on the value of λ the length-dependent Poisson frequency expectation - the number of shells expected to have k scars (4). O(k) is the number of shells observed with k scars. A Pearson goodness of fit test is done (5). Under the null hypothesis that the length-dependent Poisson distribution is 2 2 -1 2 correct, χ will be χ distributed with Kmax degrees of freedom. On a χ table check the critical value at 95% significance for this number of degrees of freedom, then if χ2 is less than this critical value then the data is not significantly different from what is expected from the age-dependent Poisson distribution (Appendix 1).

5. Results

5.1. General Results The methodology, described earlier, resulted in data of the specimens from the four groups being separated to see what trends may be extrapolated and whether taphonomic and collecting biases are evident across each group. Figure 11 shows the percentage of individuals with at least one scar for the various subdivisions of the total data gathered.

Collection Percent with at least one scar Number Fieldwork 2.500 36 All Sedgwick 35.194 410 Unsorted Sedgwick 39.189 151 Philips Cambridge 40.936 168 Cannon & Brookes 19.455 93 Figure 11 Summary data

The difference between these collections may affect further analysis and it must be considered if this resulted from variation in the living population or due to biases. The field collection which was done shows an order of magnitude lower incidence of individuals with at least one scar. All of the collections are samples from a larger supply of material.

5.2. Size distribution As mentioned, Glycimeris glycimeris were collected in parallel to the collection of Neptunea contraria to better assess biases. These are shown as Figures 12, 13 and 14, they clearly show a non-normal distribution with a positive skew which means there are more large individuals in the collections. All Figures up to Figure 22 show a non-parametric probability distribution and a fitted normality curve to show graphically the closeness of the distribution to a normal one, see Appendix 3 for normality scores.

Figure 12 Size-frequency distributions of Glycimeris glycimeris for Philips Cambridge N=122, mean =1.549. In Black fitted normal distribution, in Red with non-parametric probability density function displayed (Kernel density function)

Figure 13 Size-frequency distributions of Glycimeris glycimeris own field collection N=116, mean=0.7522. In Black fitted normal distribution, in Red with non-parametric probability density function displayed (Kernel density function)

The normal distribution is rejected for both these datasets. There is a better normality score than the material from our own field collection. Both have a positive skew. This is much more prominent in the Philips Cambridge material. The Philips Cambridge collection was expected to show a collection bias, which this data confirms as there are no specimens with a length of less than 1.5cm in it.

Figure 14 Size-frequency distribution comparison, Glycimeris glycimeris, in Red non-parametric probability density function displayed (Kernel density function)

Field Collection

Philips Cambridge Collection

Figure 15 Size-frequency distributions of broken or damaged Neptunea contraria for all Museum collections N=21. In Black fitted normal distribution, in Red with non-parametric probability density function displayed (Kernel density function)

Figure 16 Size-frequency distributions of broken or damaged Neptunea contraria for own field collection N=34. In Black fitted normal distribution, in Red with non-parametric probability density function displayed (Kernel density function)

Figures 15 and 16 show that the broken Neptunea also have a non-normal size distribution, with a positive skew, as do the unbroken individuals. The material from the field collection shows a more negative kurtosis than from the Philips Cambridge collection

Figure 17 Size-frequency distribution of Neptunea contraria from field collection N=36. In Black fitted normal distribution, in Red with non-parametric probability density function displayed (Kernel density function)

. Figure 18 Apex-Aperture length Histogram – size distribution, all collections, N=446. In Black fitted normal distribution, in Red with non-parametric probability density function displayed (Kernel density function)

The length distribution shows a near identical distribution to the distribution of whorl-length, meaning that these can both be used equally well as the size measurement for Neptunea for the purposes of this study.

Figure 19 Size-frequency histogram – all museum collections N=410. In Black fitted normal distribution, in Red with non-parametric probability density function displayed (Kernel density function)

Figure 19b Size-frequency histogram – all collections, N=446. In Black fitted normal distribution, in Red with non-parametric probability density function displayed (Kernel density function)

Figure 20 Size-frequency histogram for Cannon & Brookes Collection. In Black fitted normal distribution, in Red with non-parametric probability density function displayed (Kernel density function)

Figure 21 Size-frequency histograms for Philips Cambridge Collection. In Black fitted normal distribution, in Red with non-parametric probability density function displayed (Kernel density function)

Figure 22 Size-frequency histograms for Sedgwick Unlabelled Collection. In Black fitted normal distribution, in Red with non-parametric probability density function displayed (Kernel density function)

Figure 19 shows the size-frequency distribution for all of the Neptunea material; it has a non- normal distribution with a positive skew, indicating there is an over-representation of larger individuals as skewness=0.3407. The size-frequency distributions for the separate collections are presented above in Figures 20, 21 and 22. They show a unimodal, non-normal distribution with a prominent positive skew; therefore there are more large individuals and an under reporting of smaller, juvenile individuals

Figure 23 Size-frequencey distributions for all 3 collections, Log. In Black fitted normal distribution. Cannon & Brookes collection Philips Cambridge collection Sedgwick Unlabelled collection.

Figures 24 Size-frequency distributions for all 3 collections. In Black fitted normal distribution. Cannon & Brookes collection Philips Cambridge collection Sedgwick Unlabelled collection. Using a combined histogram, it is easier to show the Philips Cambridge Collection has a significantly tighter clustering and lower variance than the other collections. The Cannon & Brookes

26 and Sedgwick Unlabelled museum collections are, specifically the former, have a lesser degree of overrepresentation of larger individuals. The Philips Cambridge collection has the lowest kurtosis, the largest mode and the most prominent positive skew.

Cannon & Brookes collection Philips Cambridge collection Sedgwick Unlabelled collection.

Figure 25 Percentile plot

Another way of presenting this data, is a percentile plot as in Figure 25. This shows that the Cannon & Brookes collection is visibly more different from the other two collections analysed than they are from each other. At the 80th percentile the Cannon & Brookes collection is at ~15cm, whereas the others at ~23cm.

5.3. Scar-frequency Distributions

Figure 26 Whorl-length versus Scar distance, all collections

1 0,9 0,8 0,7 0,6 Probability of Scar 0,5 0,4 0,3 0,2 0,1 0 10- 15- 20- 25- 30- 35- 40- 45- 0-4.9 5-9.9 14.9 19.9 24.9 29.9 34.9 39.9 44.9 49.9 pScar 0,182 0,157 0,375 0,342 0,516 0,391 0,6 1 1 1 Whorl Length (cm)

Figure 27 The probability value of finding at least one scar on an individual from the whole dataset, divided into ten size cohorts, with standard error. The graph shows is that a larger whorl length gives a higher probability of at least one scar on an individual.

Figure 28 Terminal scar distance plated against Apex-aperture length. Least-squares, 95% confidence interval. Least-squares data in Appendix 2.

Figure 28 shows that there is a linear relationship between the Apex-Aperture length and the distance of the last scar along the whorl.

Figure 29 Terminal scar distance plotted against Whorl length. Least-squares, 95% confidence interval. Least- squares data in Appendix 2.

Figure 29 demonstrates that there is a linear relationship between the Apex-Aperture length and the distance of the last scar. More importantly it shows large snails do not have their terminal scar in the upper region of the shell.

1 0,9 0,8 0,7 0,6 Frequency 0,5 0,4 0,3 0,2 0,1 0 0 1 2 3 4 Scars per Indivdual

Figure 30 Scar frequency distribution of all Neptunea contraria

1 0,9 0,8

0,7 0-8 0,6 8.1-12 Frequency 0,5 12.1-16 0,4 16.1-24 0,3 0,2 24.1-30 0,1 30.1-48 0 0 1 2 3 4 Scars per Indivdual

Figure 31 Scar frequency distribution of all Neptunea contraria collected divided into 8cm size cohorts

1 0,9 0,8 0,7 0,6 Own Collection Frequencey 0,5 Cannon & Bookes 0,4 Philips Cambridge 0,3 Sedgwick Unlabelled 0,2 0,1 0 0 1 2 3 4 Scars per Indivdual

Figure 32 Scar Frequency distribution of Neptunea contraria divided into separate collections

Figures 31, 32 and 33 show the scar frequency distribution of the material, divided into size cohorts and by collection, and for the whole amount. The scar frequency doesn’t correspond to the null predication of a Poisson distribution for any of the size cohorts or for the whole taken together (Appendix 4). This is not consistent with a Poisson distribution of the same mean. Therefore the hypothesis that the processes of failed predation is a Poisson process; i.e. that it is a rare and random one, is incorrect. This is true for all three of the separate collections; none show a close agreement to the Poisson distribution. The χ2 test shows there is good reason to reject the null hypothesis of Poisson distribution for this data. It is likely that the data is not Poisson distributed, and the scar forming process is not a Poisson process (see Appendix 1 and 2). 30

6. Discussion

6.1. Methodology There was insufficient total material recovered from this collection to allow comparison of size- frequency distribution and scar-frequency distribution between localities, the density of complete individuals estimated prior to the fieldwork were optimistic, so insufficient material was taken. There was further limit was in transporting collected material (Dunhill et al. 2012).

6.2. Bias In general a normal distribution is often observed for a fossil population which is from a time- averaged series (Kidwell & Bosence 1991), but not in living populations, especially for species which have Type III survivorship curves as Neptunea contraria is expected to (Shimoyama 1985). The reasons for this dissimilarity must result from biases in the fossil record. The results of this project support this statement.

6.2.1. Taphonomic bias Some interesting observation and points of discussions of the data presented in Figures 18–22 include that the Cannon & Brookes Collection has a more negative kurtosis than the other collections and the Philips Cambridge Collection alone has the total absence of individual less than 6 cm whorl length. A comparison of Figure 12 and Figure 21, each from the Philips Cambridge collection, shows that they have a common size distribution; this implies there is either a common systematic bias or minimal differential taphonomic sorting of Neptunea contraria with respect to Glycimeris glycimeris. Speculatively this difference might be assigned to the dissimilar hydrodynamic properties of the shell morphologies. As shown in Fig 29, there is a linear relationship between the distance along the whorl of the scar closest to the aperture and the whorl length. Therefore there must be a high chance of an individual which survives to get a whorl length of more than 20cm receiving further scars (or a high probability of succumbing to fatal predation). The material here is time averaged so it should reflect the former community structure well (Kidwell 2001), however this data and the conclusion of Olson (1957) suggest that there is a very heavy taphonomic bias. The results of the Whorl-length versus Scar distance plot show that the taphonomic bias is considerable, which supports the conclusions of (Olson 1957) as seen in Figure 26, although the Cannon & Brookes collection has a more negative kurtosis than the other collections. Relative to the material collected in this study it seems Kidwell & Flessa (1996) found that molluscan fauna is more durable as this material is largely disarticulated, but there is a large variance in opinion. This suggests 31 the taphonomic sorting is quite large. The conflicting views of Tomasovych (2004), that small shells are less degraded versus Cooper et al. (2006) that they are more delicate is not resolved, but this data suggests the latter. Referring to Figure 14 it can be seen the field collection was done in localities from throughout the section of the Red Crag. The Philips Cambridge collection lacks locality labels, but it is presumably distributed throughout the section of the Red Crag as well. Therefore any difference in the size distributions of material from the two collections is likely to arise from collection bias, but not from different taphonomy because the size-frequency distributions are so different from the same material. The distribution of Glycimeris and Neptunea from the Philips Cambridge collection is markedly different. This is unexpected, it is possible this is a preservation effect due to the difference in shell robustness between those species.

6.2.2. Collection bias Concerning bias, the differences between the Cannon & Brookes and Philips Cambridge collections show that the level of collection bias is not constant between the collections. The original purpose of the collection affects the degree of bias. The rationale for the Cannon & Brookes collection is unknown; as opposed to Philips Cambridge collection which is the personal “hobby” collection of one dedicated individual. The particular reason for the collection could cause the degree of selectivity to change.

The effect of worker effort (Dunhill et al. 2012, Cooper et al. 2006), or rather the application of effort, in failing to make an exhaustive and unbiased size-selective sample without size-selectivity from the collector, compromises the amount of information on unsuccessful predation which can be recovered from the data. The clear bias of the workers in all the collections looked at shows that in order to properly understand the distribution of scars in Neptunea contraria a larger and more representative unbiased collection would be needed. Using finer time-bins would also help resolve this problem. As the material comes from the same geological horizon, there cannot be differential taphonomic affect between the collections; the considerable differences in the size distribution can be ascribed to collection bias.

Although there was a relative lack of Neptunea contraria in the field collection, the collection of Glycimeris glycimeris allows a good comparison, as seen in Figure 14, to be made between the field collection and the Glycimeris glycimeris in Philips Cambridge collection. This shows that there is differential collection bias between the museum and field collections on account of the very different distributions. In Figure 14, comparing the field collection and the Philips Cambridge collection, it can

32 be seen the distributions are quite distinct (Appendix 2). A non-parametric Mann-Whitney U test shows (p=0.0001) that the distributions are distinct. The null hypothesis is that the distributions of both groups are identical, therefore that an observation of a value randomly selected from one population exceeds an observation of value randomly selected from the other population has p=0.5. If the groups have identical distributions, what is the chance that random sampling would result in the mean ranks being as far apart as observed? A low p-value rejects that the null hypothesis, concluding the populations are distinct. Furthermore the median of the Philips Cambridge is significantly larger (4.9 vs 2.2), and has a much more positive kurtosis (0.9909 to -0.9723).

6.3. Scar frequency distribution As shown in Figures 26, large snails do not have their terminal scar in the upper region of the shell. Therefore there must be a high chance of an individual which survives to get beyond a whorl length of more than 20cm receiving further scars, though this may be compromised by the low sample size (N=9). Otherwise scars show a linear distribution, seen in Figures 28 and 29; this suggests that the rate of scar formation is constant over the lifetime of an individual. The analysis of Suzuki et al. (2002) agrees with this as they found that individuals with Apex-aperture length >4cm showed no size dependence in mortality; including from predation. It is interesting to note that only the Cannon & Brookes collection has a much lower incidence of individuals with at least one scar compared with the other two museum collections which collectively have a much higher incidence than the field collection. The field collection has even lower incidence as shown in Figure 32. There are several biases which could be at work here. The higher incidence of scars in the very large (>30cm Whorl length) size classes as seen in Figures 26 and 27 may result from the low sample size (N=9) of this material. This may result from size-selective removal of smaller individuals or be a result of an original feature of the population. Figure 27 shows the correlation between whorl length and the probability of an individual having at least one scar. There is a trend for the probability of a scar to increase with whorl length. The scar-frequency distribution seen in Figures 30 and 31 might be because of different levels of collections bias or it might be from sampling within the Crag: that a certain collection was sampled from an environmentally and ecologically distinct horizon(s) within the Formation; though Zalasiewicz et al. (1988) do not refer to this.

6.3.1. Unsuccessful predation Neptunea contraria has a linear growth rate and shows minimal senescence. Therefore length correlates pseudo-linearly with age, as previously mentioned (Budd pers. comm. 2016). Figure 27

33 shows large individuals do not possess scars from when they were small and juvenile. This implies there is a low chance of a snail which gains a scar when it had been small surviving and gaining scars when it was large. This may be due to non-predatory or predatory causes. There may be a bias removing shells which are small. The low number of very large shells is problem since they are so rare, general conclusions are hard to draw. There may be an energetic cost to repair implying death following from a successful repair. The material from the fieldwork contains a great percentage of broken specimens which hints at a high level of taphonomic bias. Since the sample size is small (41 pieces identifiable as Neptunea), the “real” number of individuals is likely to be significantly larger than this, as demonstrated by Gilinsky & Bennington (1994). This describes the errors at being lower for organisms with a low count of body parts, which is applicable to Neptunea. The χ2 test shows there is good reason to reject the null hypothesis of Poisson distribution for this data with p=0.9999 (Appendix 2). Owing to the way this test was structured a high p-value means a very strong rejection of Poisson distribution for this data. The results indicate that the assumption that the scar formation process in Neptunea contraria is a Poisson process is essentially incorrect. The reason for the data not correlating with a Poisson process is unknown. It would be very unexpected if the event of failed predation was not rare, not independent of previous events, nor random. The most likely conclusion is that the rate of predation is not constant over the lifetime of an organism, and is therefore age dependant. The rate of failed predation, by implication the rate of predation, is therefore not constant throughout the lifetime of an individual based on the data presented in Figure 31. This is a line of further investigation to determine the how such rate changes over the lifetime. Speculatively this implies that the lack of smaller individuals is due a differential rate with a lower chance of survival for the smaller individuals. This data is not definitive owing the possibility of underreporting of smaller individuals due to taphonomic, post mortem process. It could also be a natural property of the population structure: distinguishing these alternatives can be difficult. Unsuccessful predation shows some clustering; since the correlation of unsuccessful predation frequency with successful predation frequency (Vermeij 1982b) means to first order there is a difference in the incidence of predation over an individual’s lifetime. This is complicated by several problems, which will be discussed below. The scenario of a low rate of scar formation can be caused by a high rate of attack with a low rate of survival or a low (to moderate) rate of predation with high survival, where it is hard to distinguish these possibilities (Vermeij 1976). Since the morphology of Neptunea contraria is left-handed and has a conical form it would be expected to have a higher rate of survival so that option is favoured (Vermeij 1982c, Dietl & Hendricks 2006). The findings and assumptions of Griffiths & Gosselin 2008 (also Vermeij 1976), that the predation susceptibility of juveniles is not linearly related to size, but rather undergoes some dramatic decrease on reaching a certain specific value, is supported by these findings. It is concluded that the scar distribution is indicative of such a process.

Leighton (2002) notes changes in repair frequency can be a result of increases or decreases in predation intensity. The results of this report suggest there is insufficient agreement for this species and time slice between the living and dead population given the material studied in the population distribution. More in depth sampling would be needed to determine the degree to which this is the case.

7. Conclusion The principle points discussed in this report have been the extent of taphonomic bias, collection induced bias in Neptunea contraria and the distribution of failed predation scars in the same species, the distribution of which provides information on predation distribution in Neptunea contraria. The magnitude and incidence of predation of Neptunea contraria of the Red Crag and the biases in the material – taphonomic and collection were analysed and related to the concept of predation potential as an evolutionary driving force. A large number of ecological and evolutionary studies are based on museum collections and in order for the results to be valid we need to be aware of biases that affect museum collections in particular. This study shows that there are considerable biases that intervene between the living population and collections that can be observed in a museum. This can be seen in the size distribution and the scar-frequency distribution as shown in the discussion of taphonomic and collections bias. The primary purpose of the report was to see if data necessary to comment on the potential effect of predation as an evolutionary mechanism can be reliably generated but that it is difficult to do so. Further studies could be carried out to better analyse this problem. It would be interesting to observe the some further points as potential for future work such as the effect of environmental gradients on scar frequency and size distribution. The nature of these distributions from a geographically disparate population would also be a line of future investigation, it would also be good to filter out the of hermit crab caused shell re-use signal with a differential wear metric. It would also be interesting to compare to a more intensive field collection to gain the necessary number of Neptunea contraria to properly assess the degree of collection and taphonomic bias, since there was an insufficiently large sampling.

8. Acknowledgements I would like to thank Richard Mann, University of Leeds, for assistance with calculations, to Graham Budd, Uppsala University for supervising the project, to Matt Riley, University of Cambridge, Liz Harper, University of Cambridge for assistance with data collection at Sedgwick Museum, to Mohamad Bazzi for translating the popular scientific summary, to Aodhán Butler, Uppsala University and Lars Holmer, Uppsala University as the subject reviewer and examiner, also my sister Jessica Seale for her support and encouragement.

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Appendix 1. χ2 Test Calculation

( ) = 𝑛𝑛 + ( ) ( !)

𝐿𝐿 𝜆𝜆 ��𝑥𝑥𝑖𝑖𝜆𝜆 𝑦𝑦𝑖𝑖𝑙𝑙𝑙𝑙𝑙𝑙 𝑥𝑥𝑖𝑖𝜆𝜆 − 𝑙𝑙𝑙𝑙𝑙𝑙 𝑦𝑦𝑖𝑖 � (1) Log-likelihood function i=1 ( ) = 0 = 𝑛𝑛 + 𝑑𝑑 𝐿𝐿 𝑦𝑦𝑖𝑖 � 𝑥𝑥𝑖𝑖 (2) Maximum likelihood function 𝑑𝑑𝑑𝑑 𝑖𝑖=1 𝜆𝜆

= 𝑛𝑛 ∑𝑖𝑖=1 𝑦𝑦𝑖𝑖 𝜆𝜆 𝑛𝑛 (3) Best fit for λ ∑𝑖𝑖=1 𝑥𝑥𝑖𝑖 ( ) exp( ) ( ) = 𝑛𝑛 < 𝑘𝑘 ! 𝑥𝑥𝑖𝑖𝜆𝜆 −𝑥𝑥𝑖𝑖𝜆𝜆 𝐸𝐸 𝑘𝑘 � ∀𝑘𝑘 𝑘𝑘𝑚𝑚𝑚𝑚𝑚𝑚 𝑖𝑖=1 𝑘𝑘 ( ) = 𝑘𝑘𝑚𝑚𝑚𝑚𝑚𝑚−1 ( )

𝐸𝐸 𝑘𝑘𝑚𝑚𝑚𝑚𝑚𝑚 𝑛𝑛 − � 𝐸𝐸 𝐾𝐾 (4) Poisson frequency expectation; length dependant𝑖𝑖= 1

O( ) ( ) = 𝑘𝑘𝑚𝑚𝑚𝑚𝑚𝑚 ( ) 2 2 � 𝑘𝑘 − 𝐸𝐸 𝑘𝑘 � 2 𝜒𝜒 � (5) χ Goodness of fit test 𝑖𝑖=1 𝐸𝐸 𝑘𝑘

Definitions: n number of shells

{xi,…,xn} whorl lengths of the shells

{yi,…,yn} number of scars on the shells kmax most scars on any one shell

Appendix 2. Calculation Data Tables Poisson and χ2 Whorl (cm) Whorl*lambda p0 p1 p2 p3 p4++ scars 7.6 0.211964858 0.808993 0.171478 0.009087 0.001284 0.009158 2 Total N of Scars 182 20 0.557802259 0.572466 0.319323 0.04453 0.016559 0.047123 2 Sum Whorl Length of 19.4 all Shells 6525.61 0.541068191 0.582126 0.31497 0.042605 0.015368 0.044931 4 N Shells 410 9.8 0.273323107 0.760847 0.207957 0.01421 0.002589 0.014397 2 Mean scars per shell 0.4439 6.6 0.184074746 0.831874 0.153127 0.007047 0.000865 0.007088 2 λ 0.02789 9.6 0.267745084 0.765103 0.204853 0.013712 0.002448 0.013885 2 16.7 0.465764886 0.627655 0.29234 0.03404 0.01057 0.035395 2 E(kmax) 14.4703 11.1 0.309580254 0.733755 0.227156 0.017581 0.003628 0.01788 2 E(k) 3 5.13766 16.8 0.468553898 0.625907 0.293271 0.034353 0.010731 0.035738 2 E(k) 2 13.5294 12.2 0.340259378 0.711586 0.242124 0.020596 0.004672 0.021022 3 E(k) 1 108.558 15 0.418351694 0.658131 0.27533 0.028796 0.008031 0.029712 2 E(K) 0 268.305 16.8 0.468553898 0.625907 0.293271 0.034353 0.010731 0.035738 2 14 0.390461581 0.676744 0.264243 0.025794 0.006714 0.026504 2 18.5 0.51596709 0.596923 0.307993 0.039729 0.013666 0.04169 2 Actual (k) 0 265 17 0.47413192 0.622425 0.295112 0.03498 0.011057 0.036426 2 Actual (k) 1 114 16 0.446241807 0.640029 0.285608 0.031863 0.009479 0.033022 2 Actual (k) 2 27 18.5 0.51596709 0.596923 0.307993 0.039729 0.013666 0.04169 3 Actual (k) 3 2 15.4 0.42950774 0.650829 0.279536 0.030016 0.008595 0.031024 2 Actual (k) max 2 17 0.47413192 0.622425 0.295112 0.03498 0.011057 0.036426 2 17.2 0.479709943 0.618963 0.296923 0.035609 0.011388 0.037117 2 (Actual - Expected)^2/Expected 20.8 k=0 0.04071 0.580114349 0.559834 0.324768 0.047101 0.018216 0.050081 2 (Actual- Expected)^2/Expected 18.6 k=1 0.27285 0.518756101 0.595261 0.308795 0.040047 0.01385 0.042047 2 (Actual- Expected)^2/Expected 20 k=2 13.412 0.557802259 0.572466 0.319323 0.04453 0.016559 0.047123 2 (Actual- Expected)^2/Expected 27.2 k=3 1.91622 0.758611072 0.468316 0.35527 0.067378 0.034076 0.07496 2 (Actual- Expected)^2/Expected 23.2 k max 10.7467 0.647050621 0.523588 0.338788 0.054803 0.02364 0.059181 2 36.9 1.029145168 0.357312 0.367726 0.094611 0.064912 0.115438 4 Chi^2 26.3885 23.5 0.655417654 0.519225 0.340309 0.055761 0.024365 0.06034 2 Degree of freedom 4 24.9 0.694463813 0.499342 0.346775 0.060206 0.027874 0.065803 2 P-value 0.99997 47.52 1.325338168 0.265713 0.35216 0.116683 0.103096 0.162349 2 Reject Poisson? TRUE 32.1 0.895272626 0.408496 0.365715 0.081854 0.048854 0.09508 2 43 1.199274857 0.301413 0.361477 0.108377 0.08665 0.142084 2 4 0.111560452 0.894437 0.099784 0.002783 0.000207 0.002789 1 6.5 0.181285734 0.834197 0.151228 0.006854 0.000828 0.006893 1 20 0.557802259 0.572466 0.319323 0.04453 0.016559 0.047123 1 4.4 0.122716497 0.884514 0.108545 0.00333 0.000272 0.003339 1 10.4 0.290057175 0.748221 0.217027 0.015738 0.003043 0.015972 1 15.9 0.443452796 0.641817 0.284615 0.031553 0.009328 0.032686 1 3.1 0.08645935 0.917173 0.079298 0.001714 9.88E-05 0.001716 1 10 0.27890113 0.756615 0.211021 0.014713 0.002736 0.014915 1 20 0.557802259 0.572466 0.319323 0.04453 0.016559 0.047123 1 8.2 0.228698926 0.795568 0.181946 0.010403 0.001586 0.010498 1 16.9 0.471342909 0.624164 0.294195 0.034667 0.010893 0.036081 1 4.1 0.114349463 0.891946 0.101994 0.002916 0.000222 0.002922 1 25.6 0.713986892 0.489688 0.349631 0.062408 0.029706 0.068568 1 14.4 0.401617627 0.669237 0.268777 0.026986 0.007225 0.027774 1 24 0.669362711 0.512035 0.342737 0.057354 0.025594 0.062281 1 10.1 0.281690141 0.754507 0.212537 0.014967 0.002811 0.015177 1 13 0.362571468 0.695885 0.252308 0.02287 0.005528 0.02341 1 24.2 0.674940734 0.509187 0.343671 0.057989 0.026093 0.06306 1 13.5 0.376516525 0.686248 0.258384 0.024321 0.006105 0.024942 1 12.6 0.351415423 0.703691 0.247288 0.021725 0.00509 0.022206 1 12.5 0.348626412 0.705657 0.246011 0.021441 0.004983 0.021908 1 9 0.251011017 0.778014 0.19529 0.012255 0.002051 0.01239 1 7.5 0.209175847 0.811253 0.169694 0.008874 0.001237 0.008942 1 7.5 0.209175847 0.811253 0.169694 0.008874 0.001237 0.008942 1

25.9 0.722353926 0.485608 0.350781 0.063347 0.030506 0.069759 1 20 0.557802259 0.572466 0.319323 0.04453 0.016559 0.047123 1 9 0.251011017 0.778014 0.19529 0.012255 0.002051 0.01239 1 8.3 0.231487938 0.793352 0.183651 0.010628 0.00164 0.010728 1 20.7 0.577325338 0.561398 0.324109 0.046779 0.018005 0.049709 1 8.9 0.248222005 0.780187 0.19366 0.012018 0.001989 0.012147 1 14 0.390461581 0.676744 0.264243 0.025794 0.006714 0.026504 1 17.3 0.482498954 0.617239 0.297817 0.035924 0.011556 0.037464 1 18 0.502022033 0.605305 0.303877 0.038138 0.012764 0.039916 1 9.4 0.262167062 0.769382 0.201707 0.01322 0.002311 0.01338 1 11.4 0.317947288 0.727641 0.231352 0.018389 0.003898 0.01872 1 15.5 0.432296751 0.649017 0.280568 0.030322 0.008739 0.031354 1 12.6 0.351415423 0.703691 0.247288 0.021725 0.00509 0.022206 1 17.6 0.490865988 0.612096 0.300457 0.036871 0.012066 0.03851 1 24.6 0.686096779 0.503538 0.345476 0.059257 0.027104 0.064625 1 11.2 0.312369265 0.731711 0.228564 0.017849 0.003717 0.018158 1 14.2 0.396039604 0.67298 0.266527 0.026389 0.006967 0.027137 1 24.1 0.672151722 0.510609 0.343207 0.057672 0.025843 0.06267 1 16.2 0.45181983 0.636469 0.287569 0.032482 0.009784 0.033695 1 14.2 0.396039604 0.67298 0.266527 0.026389 0.006967 0.027137 1 11.5 0.320736299 0.725615 0.232731 0.018661 0.00399 0.019003 1 17.1 0.476920932 0.620692 0.296021 0.035295 0.011222 0.036771 1 20 0.557802259 0.572466 0.319323 0.04453 0.016559 0.047123 1 21.1 0.588481383 0.55517 0.326707 0.048065 0.018857 0.051201 1 14.4 0.401617627 0.669237 0.268777 0.026986 0.007225 0.027774 1 21.2 0.591270395 0.553624 0.327341 0.048387 0.019073 0.051575 1 18.1 0.504811044 0.60362 0.304714 0.038456 0.012942 0.040269 1 12.7 0.354204435 0.701731 0.248556 0.02201 0.005197 0.022505 1 18 0.502022033 0.605305 0.303877 0.038138 0.012764 0.039916 1 13.3 0.370938502 0.690086 0.25598 0.023738 0.00587 0.024326 1 17.8 0.496444011 0.608691 0.302181 0.037504 0.012412 0.039211 1 13.5 0.376516525 0.686248 0.258384 0.024321 0.006105 0.024942 1 17.4 0.485287965 0.61552 0.298704 0.036239 0.011724 0.037812 1 19.2 0.535490169 0.585382 0.313466 0.041965 0.014981 0.044206 1 15.8 0.440663785 0.643609 0.283615 0.031245 0.009179 0.032352 1 13.5 0.376516525 0.686248 0.258384 0.024321 0.006105 0.024942 1 19.3 0.53827918 0.583752 0.314222 0.042285 0.015174 0.044568 1 22.5 0.627527541 0.53391 0.335043 0.052562 0.02199 0.056495 1 23 0.641472598 0.526517 0.337746 0.054164 0.023163 0.058411 1 19.8 0.552224237 0.575668 0.317898 0.043888 0.016157 0.046389 1 20 0.557802259 0.572466 0.319323 0.04453 0.016559 0.047123 1 20.1 0.56059127 0.570871 0.320026 0.044851 0.016762 0.04749 1 31.5 0.878538558 0.41539 0.364936 0.080153 0.046945 0.092577 1 24.4 0.680518756 0.506354 0.344584 0.058624 0.026596 0.063842 1 18.5 0.51596709 0.596923 0.307993 0.039729 0.013666 0.04169 1 24 0.669362711 0.512035 0.342737 0.057354 0.025594 0.062281 1 14 0.390461581 0.676744 0.264243 0.025794 0.006714 0.026504 1 16 0.446241807 0.640029 0.285608 0.031863 0.009479 0.033022 1 23.7 0.660995677 0.516337 0.341297 0.056399 0.024853 0.061115 1 15.8 0.440663785 0.643609 0.283615 0.031245 0.009179 0.032352 1 23.4 0.652628643 0.520675 0.339808 0.055442 0.024122 0.059953 1 17.2 0.479709943 0.618963 0.296923 0.035609 0.011388 0.037117 1 19 0.529912146 0.588657 0.311936 0.041325 0.014599 0.043483 1 15.4 0.42950774 0.650829 0.279536 0.030016 0.008595 0.031024 1 22.5 0.627527541 0.53391 0.335043 0.052562 0.02199 0.056495 1 18.7 0.521545112 0.593603 0.309591 0.040366 0.014035 0.042405 1 20.9 0.582903361 0.558275 0.32542 0.047422 0.018428 0.050454 1 20.6 0.574536327 0.562966 0.323444 0.046458 0.017794 0.049338 1 17 0.47413192 0.622425 0.295112 0.03498 0.011057 0.036426 1 18.5 0.51596709 0.596923 0.307993 0.039729 0.013666 0.04169 1 24.6 0.686096779 0.503538 0.345476 0.059257 0.027104 0.064625 1 24 0.669362711 0.512035 0.342737 0.057354 0.025594 0.062281 1 22.1 0.616371496 0.5399 0.332779 0.051279 0.021071 0.054971 1 23.8 0.663784688 0.514899 0.341782 0.056717 0.025099 0.061503 1 19.65 0.54804072 0.578081 0.316812 0.043406 0.015859 0.045841 1 20.8 0.580114349 0.559834 0.324768 0.047101 0.018216 0.050081 1 23.6 0.658206666 0.517779 0.340806 0.05608 0.024608 0.060727 1 25.6 0.713986892 0.489688 0.349631 0.062408 0.029706 0.068568 1 20.6 0.574536327 0.562966 0.323444 0.046458 0.017794 0.049338 1 21 0.585692372 0.55672 0.326067 0.047744 0.018642 0.050827 1 23 0.641472598 0.526517 0.337746 0.054164 0.023163 0.058411 1 22.6 0.630316553 0.532423 0.335595 0.052883 0.022222 0.056877 1

26 0.725142937 0.484255 0.351154 0.063659 0.030775 0.070156 1 28.6 0.797657231 0.450383 0.359251 0.07164 0.038096 0.08063 1 22 0.613582485 0.541408 0.332198 0.050958 0.020845 0.054592 1 23.8 0.663784688 0.514899 0.341782 0.056717 0.025099 0.061503 1 24 0.669362711 0.512035 0.342737 0.057354 0.025594 0.062281 1 21 0.585692372 0.55672 0.326067 0.047744 0.018642 0.050827 1 21.4 0.596848417 0.550544 0.328591 0.04903 0.019509 0.052326 1 25.9 0.722353926 0.485608 0.350781 0.063347 0.030506 0.069759 1 21 0.585692372 0.55672 0.326067 0.047744 0.018642 0.050827 1 21.5 0.599637429 0.549011 0.329207 0.049351 0.019729 0.052702 1 23 0.641472598 0.526517 0.337746 0.054164 0.023163 0.058411 1 25 0.697252824 0.497951 0.347198 0.060521 0.028132 0.066197 1 21 0.585692372 0.55672 0.326067 0.047744 0.018642 0.050827 1 27.9 0.778134151 0.459262 0.357368 0.06952 0.036064 0.077786 1 23.5 0.655417654 0.519225 0.340309 0.055761 0.024365 0.06034 1 24.5 0.683307767 0.504944 0.345032 0.058941 0.02685 0.064233 1 31.5 0.878538558 0.41539 0.364936 0.080153 0.046945 0.092577 1 38.5 1.073769349 0.341718 0.366926 0.098499 0.07051 0.122347 1 2 0.055780226 0.945747 0.052754 0.000736 2.74E-05 0.000736 0 2 0.055780226 0.945747 0.052754 0.000736 2.74E-05 0.000736 0 2 0.055780226 0.945747 0.052754 0.000736 2.74E-05 0.000736 0 2.6 0.072514294 0.930052 0.067442 0.001223 5.91E-05 0.001224 0 2.6 0.072514294 0.930052 0.067442 0.001223 5.91E-05 0.001224 0 3.1 0.08645935 0.917173 0.079298 0.001714 9.88E-05 0.001716 0 3.1 0.08645935 0.917173 0.079298 0.001714 9.88E-05 0.001716 0 3.3 0.092037373 0.912071 0.083945 0.001932 0.000119 0.001934 0 3.3 0.092037373 0.912071 0.083945 0.001932 0.000119 0.001934 0 3.7 0.103193418 0.901953 0.093076 0.002401 0.000165 0.002406 0 3.9 0.108771441 0.896935 0.097561 0.002653 0.000192 0.002658 0 4 0.111560452 0.894437 0.099784 0.002783 0.000207 0.002789 0 4.1 0.114349463 0.891946 0.101994 0.002916 0.000222 0.002922 0 4.3 0.119927486 0.886985 0.106374 0.003189 0.000255 0.003197 0 4.8 0.133872542 0.874702 0.117099 0.003919 0.00035 0.003931 0 4.8 0.133872542 0.874702 0.117099 0.003919 0.00035 0.003931 0 4.8 0.133872542 0.874702 0.117099 0.003919 0.00035 0.003931 0 4.8 0.133872542 0.874702 0.117099 0.003919 0.00035 0.003931 0 5 0.139450565 0.869836 0.121299 0.004229 0.000393 0.004243 0 5.1 0.142239576 0.867413 0.123381 0.004387 0.000416 0.004403 0 5.1 0.142239576 0.867413 0.123381 0.004387 0.000416 0.004403 0 5.5 0.153395621 0.85779 0.131581 0.005046 0.000516 0.005066 0 5.5 0.153395621 0.85779 0.131581 0.005046 0.000516 0.005066 0 5.6 0.156184633 0.855401 0.133601 0.005217 0.000543 0.005238 0 5.6 0.156184633 0.855401 0.133601 0.005217 0.000543 0.005238 0 5.8 0.161762655 0.850643 0.137602 0.005565 0.0006 0.00559 0 5.8 0.161762655 0.850643 0.137602 0.005565 0.0006 0.00559 0 5.9 0.164551666 0.848274 0.139585 0.005742 0.00063 0.005769 0 5.9 0.164551666 0.848274 0.139585 0.005742 0.00063 0.005769 0 6 0.167340678 0.845911 0.141555 0.005922 0.000661 0.005951 0 6 0.167340678 0.845911 0.141555 0.005922 0.000661 0.005951 0 6 0.167340678 0.845911 0.141555 0.005922 0.000661 0.005951 0 6 0.167340678 0.845911 0.141555 0.005922 0.000661 0.005951 0 6.2 0.1729187 0.841206 0.14546 0.006288 0.000725 0.006321 0 6.2 0.1729187 0.841206 0.14546 0.006288 0.000725 0.006321 0 6.3 0.175707712 0.838863 0.147395 0.006475 0.000758 0.006509 0 6.5 0.181285734 0.834197 0.151228 0.006854 0.000828 0.006893 0 6.5 0.181285734 0.834197 0.151228 0.006854 0.000828 0.006893 0 6.5 0.181285734 0.834197 0.151228 0.006854 0.000828 0.006893 0 6.6 0.184074746 0.831874 0.153127 0.007047 0.000865 0.007088 0 6.6 0.184074746 0.831874 0.153127 0.007047 0.000865 0.007088 0 6.6 0.184074746 0.831874 0.153127 0.007047 0.000865 0.007088 0 6.6 0.184074746 0.831874 0.153127 0.007047 0.000865 0.007088 0 6.6 0.184074746 0.831874 0.153127 0.007047 0.000865 0.007088 0 6.7 0.186863757 0.829557 0.155014 0.007242 0.000902 0.007285 0 6.8 0.189652768 0.827246 0.15689 0.007439 0.000941 0.007485 0 6.8 0.189652768 0.827246 0.15689 0.007439 0.000941 0.007485 0 6.8 0.189652768 0.827246 0.15689 0.007439 0.000941 0.007485 0 6.9 0.192441779 0.824942 0.158753 0.007638 0.00098 0.007687 0 7 0.195230791 0.822645 0.160606 0.007839 0.00102 0.007891 0 7 0.195230791 0.822645 0.160606 0.007839 0.00102 0.007891 0 7 0.195230791 0.822645 0.160606 0.007839 0.00102 0.007891 0 7.2 0.200808813 0.818069 0.164275 0.008247 0.001104 0.008305 0 7.2 0.200808813 0.818069 0.164275 0.008247 0.001104 0.008305 0

7.2 0.200808813 0.818069 0.164275 0.008247 0.001104 0.008305 0 7.3 0.203597825 0.81579 0.166093 0.008454 0.001147 0.008515 0 7.3 0.203597825 0.81579 0.166093 0.008454 0.001147 0.008515 0 7.4 0.206386836 0.813518 0.167899 0.008663 0.001192 0.008727 0 7.4 0.206386836 0.813518 0.167899 0.008663 0.001192 0.008727 0 7.5 0.209175847 0.811253 0.169694 0.008874 0.001237 0.008942 0 7.5 0.209175847 0.811253 0.169694 0.008874 0.001237 0.008942 0 7.8 0.217542881 0.804493 0.175012 0.009518 0.00138 0.009597 0 7.9 0.220331892 0.802252 0.176762 0.009737 0.00143 0.009819 0 7.9 0.220331892 0.802252 0.176762 0.009737 0.00143 0.009819 0 8 0.223120904 0.800018 0.178501 0.009957 0.001481 0.010043 0 8 0.223120904 0.800018 0.178501 0.009957 0.001481 0.010043 0 8 0.223120904 0.800018 0.178501 0.009957 0.001481 0.010043 0 8.1 0.225909915 0.79779 0.180229 0.010179 0.001533 0.01027 0 8.1 0.225909915 0.79779 0.180229 0.010179 0.001533 0.01027 0 8.2 0.228698926 0.795568 0.181946 0.010403 0.001586 0.010498 0 8.2 0.228698926 0.795568 0.181946 0.010403 0.001586 0.010498 0 8.3 0.231487938 0.793352 0.183651 0.010628 0.00164 0.010728 0 8.3 0.231487938 0.793352 0.183651 0.010628 0.00164 0.010728 0 8.4 0.234276949 0.791143 0.185346 0.010856 0.001695 0.01096 0 8.4 0.234276949 0.791143 0.185346 0.010856 0.001695 0.01096 0 8.6 0.239854971 0.786742 0.188704 0.011315 0.001809 0.011429 0 8.8 0.245432994 0.782366 0.192018 0.011782 0.001928 0.011906 0 8.8 0.245432994 0.782366 0.192018 0.011782 0.001928 0.011906 0 8.9 0.248222005 0.780187 0.19366 0.012018 0.001989 0.012147 0 9 0.251011017 0.778014 0.19529 0.012255 0.002051 0.01239 0 9 0.251011017 0.778014 0.19529 0.012255 0.002051 0.01239 0 9.2 0.256589039 0.773686 0.198519 0.012734 0.002178 0.012882 0 9.3 0.25937805 0.771531 0.200118 0.012977 0.002244 0.01313 0 9.4 0.262167062 0.769382 0.201707 0.01322 0.002311 0.01338 0 9.4 0.262167062 0.769382 0.201707 0.01322 0.002311 0.01338 0 9.4 0.262167062 0.769382 0.201707 0.01322 0.002311 0.01338 0 9.6 0.267745084 0.765103 0.204853 0.013712 0.002448 0.013885 0 9.9 0.276112118 0.758728 0.209494 0.014461 0.002662 0.014655 0 10 0.27890113 0.756615 0.211021 0.014713 0.002736 0.014915 0 10 0.27890113 0.756615 0.211021 0.014713 0.002736 0.014915 0 10.4 0.290057175 0.748221 0.217027 0.015738 0.003043 0.015972 0 10.4 0.290057175 0.748221 0.217027 0.015738 0.003043 0.015972 0 10.7 0.298424209 0.741987 0.221427 0.01652 0.003287 0.01678 0 10.8 0.30121322 0.73992 0.222874 0.016783 0.00337 0.017053 0 11 0.306791243 0.735804 0.225738 0.017314 0.003541 0.017603 0 11 0.306791243 0.735804 0.225738 0.017314 0.003541 0.017603 0 11 0.306791243 0.735804 0.225738 0.017314 0.003541 0.017603 0 11.3 0.315158276 0.729673 0.229963 0.018119 0.003807 0.018439 0 11.3 0.315158276 0.729673 0.229963 0.018119 0.003807 0.018439 0 11.4 0.317947288 0.727641 0.231352 0.018389 0.003898 0.01872 0 12 0.334681355 0.715566 0.239487 0.020038 0.004471 0.020439 0 12.1 0.337470367 0.713573 0.24081 0.020317 0.004571 0.02073 0 12.3 0.343048389 0.709604 0.243428 0.020877 0.004775 0.021316 0 12.5 0.348626412 0.705657 0.246011 0.021441 0.004983 0.021908 0 12.5 0.348626412 0.705657 0.246011 0.021441 0.004983 0.021908 0 12.5 0.348626412 0.705657 0.246011 0.021441 0.004983 0.021908 0 12.8 0.356993446 0.699777 0.249816 0.022296 0.005306 0.022805 0 13 0.362571468 0.695885 0.252308 0.02287 0.005528 0.02341 0 13 0.362571468 0.695885 0.252308 0.02287 0.005528 0.02341 0 13 0.362571468 0.695885 0.252308 0.02287 0.005528 0.02341 0 13 0.362571468 0.695885 0.252308 0.02287 0.005528 0.02341 0 13.1 0.36536048 0.693946 0.253541 0.023158 0.005641 0.023714 0 13.3 0.370938502 0.690086 0.25598 0.023738 0.00587 0.024326 0 13.3 0.370938502 0.690086 0.25598 0.023738 0.00587 0.024326 0 13.5 0.376516525 0.686248 0.258384 0.024321 0.006105 0.024942 0 13.6 0.379305536 0.684336 0.259573 0.024614 0.006224 0.025252 0 13.6 0.379305536 0.684336 0.259573 0.024614 0.006224 0.025252 0 13.9 0.38767257 0.678635 0.263088 0.025498 0.00659 0.02619 0 13.9 0.38767257 0.678635 0.263088 0.025498 0.00659 0.02619 0 14 0.390461581 0.676744 0.264243 0.025794 0.006714 0.026504 0 14.1 0.393250593 0.67486 0.265389 0.026091 0.00684 0.02682 0 14.2 0.396039604 0.67298 0.266527 0.026389 0.006967 0.027137 0 14.4 0.401617627 0.669237 0.268777 0.026986 0.007225 0.027774 0 14.5 0.404406638 0.667373 0.26989 0.027286 0.007357 0.028095 0 14.5 0.404406638 0.667373 0.26989 0.027286 0.007357 0.028095 0 14.8 0.412773672 0.661812 0.273179 0.02819 0.007757 0.029062 0

14.9 0.415562683 0.659969 0.274258 0.028493 0.007894 0.029386 0 14.9 0.415562683 0.659969 0.274258 0.028493 0.007894 0.029386 0 15 0.418351694 0.658131 0.27533 0.028796 0.008031 0.029712 0 15 0.418351694 0.658131 0.27533 0.028796 0.008031 0.029712 0 15 0.418351694 0.658131 0.27533 0.028796 0.008031 0.029712 0 15 0.418351694 0.658131 0.27533 0.028796 0.008031 0.029712 0 15 0.418351694 0.658131 0.27533 0.028796 0.008031 0.029712 0 15 0.418351694 0.658131 0.27533 0.028796 0.008031 0.029712 0 15.1 0.421140706 0.656298 0.276394 0.0291 0.00817 0.030038 0 15.1 0.421140706 0.656298 0.276394 0.0291 0.00817 0.030038 0 15.1 0.421140706 0.656298 0.276394 0.0291 0.00817 0.030038 0 15.2 0.423929717 0.65447 0.277449 0.029405 0.00831 0.030366 0 15.2 0.423929717 0.65447 0.277449 0.029405 0.00831 0.030366 0 15.3 0.426718728 0.652647 0.278497 0.02971 0.008452 0.030694 0 15.3 0.426718728 0.652647 0.278497 0.02971 0.008452 0.030694 0 15.4 0.42950774 0.650829 0.279536 0.030016 0.008595 0.031024 0 15.5 0.432296751 0.649017 0.280568 0.030322 0.008739 0.031354 0 16 0.446241807 0.640029 0.285608 0.031863 0.009479 0.033022 0 16 0.446241807 0.640029 0.285608 0.031863 0.009479 0.033022 0 16 0.446241807 0.640029 0.285608 0.031863 0.009479 0.033022 0 16.1 0.449030819 0.638246 0.286592 0.032172 0.009631 0.033358 0 16.1 0.449030819 0.638246 0.286592 0.032172 0.009631 0.033358 0 16.1 0.449030819 0.638246 0.286592 0.032172 0.009631 0.033358 0 16.1 0.449030819 0.638246 0.286592 0.032172 0.009631 0.033358 0 16.2 0.45181983 0.636469 0.287569 0.032482 0.009784 0.033695 0 16.2 0.45181983 0.636469 0.287569 0.032482 0.009784 0.033695 0 16.5 0.460186864 0.631166 0.290454 0.033416 0.010252 0.034713 0 16.5 0.460186864 0.631166 0.290454 0.033416 0.010252 0.034713 0 16.5 0.460186864 0.631166 0.290454 0.033416 0.010252 0.034713 0 16.8 0.468553898 0.625907 0.293271 0.034353 0.010731 0.035738 0 17 0.47413192 0.622425 0.295112 0.03498 0.011057 0.036426 0 17 0.47413192 0.622425 0.295112 0.03498 0.011057 0.036426 0 17 0.47413192 0.622425 0.295112 0.03498 0.011057 0.036426 0 17.1 0.476920932 0.620692 0.296021 0.035295 0.011222 0.036771 0 17.14 0.478036536 0.62 0.296382 0.03542 0.011288 0.036909 0 17.2 0.479709943 0.618963 0.296923 0.035609 0.011388 0.037117 0 17.2 0.479709943 0.618963 0.296923 0.035609 0.011388 0.037117 0 17.2 0.479709943 0.618963 0.296923 0.035609 0.011388 0.037117 0 17.3 0.482498954 0.617239 0.297817 0.035924 0.011556 0.037464 0 17.3 0.482498954 0.617239 0.297817 0.035924 0.011556 0.037464 0 17.4 0.485287965 0.61552 0.298704 0.036239 0.011724 0.037812 0 17.5 0.488076977 0.613806 0.299584 0.036555 0.011894 0.03816 0 17.5 0.488076977 0.613806 0.299584 0.036555 0.011894 0.03816 0 17.6 0.490865988 0.612096 0.300457 0.036871 0.012066 0.03851 0 17.6 0.490865988 0.612096 0.300457 0.036871 0.012066 0.03851 0 17.6 0.490865988 0.612096 0.300457 0.036871 0.012066 0.03851 0 17.7 0.493654999 0.610391 0.301323 0.037187 0.012238 0.03886 0 17.8 0.496444011 0.608691 0.302181 0.037504 0.012412 0.039211 0 18 0.502022033 0.605305 0.303877 0.038138 0.012764 0.039916 0 18 0.502022033 0.605305 0.303877 0.038138 0.012764 0.039916 0 18 0.502022033 0.605305 0.303877 0.038138 0.012764 0.039916 0 18 0.502022033 0.605305 0.303877 0.038138 0.012764 0.039916 0 18.1 0.504811044 0.60362 0.304714 0.038456 0.012942 0.040269 0 18.1 0.504811044 0.60362 0.304714 0.038456 0.012942 0.040269 0 18.2 0.507600056 0.601938 0.305544 0.038774 0.013121 0.040623 0 18.2 0.507600056 0.601938 0.305544 0.038774 0.013121 0.040623 0 18.3 0.510389067 0.600262 0.306367 0.039092 0.013301 0.040978 0 18.5 0.51596709 0.596923 0.307993 0.039729 0.013666 0.04169 0 18.5 0.51596709 0.596923 0.307993 0.039729 0.013666 0.04169 0 18.6 0.518756101 0.595261 0.308795 0.040047 0.01385 0.042047 0 18.6 0.518756101 0.595261 0.308795 0.040047 0.01385 0.042047 0 18.7 0.521545112 0.593603 0.309591 0.040366 0.014035 0.042405 0 18.7 0.521545112 0.593603 0.309591 0.040366 0.014035 0.042405 0 18.8 0.524334124 0.591949 0.310379 0.040686 0.014222 0.042764 0 19 0.529912146 0.588657 0.311936 0.041325 0.014599 0.043483 0 19 0.529912146 0.588657 0.311936 0.041325 0.014599 0.043483 0 19 0.529912146 0.588657 0.311936 0.041325 0.014599 0.043483 0 19 0.529912146 0.588657 0.311936 0.041325 0.014599 0.043483 0 19 0.529912146 0.588657 0.311936 0.041325 0.014599 0.043483 0 19 0.529912146 0.588657 0.311936 0.041325 0.014599 0.043483 0 19.1 0.532701157 0.587017 0.312705 0.041645 0.014789 0.043844 0 19.1 0.532701157 0.587017 0.312705 0.041645 0.014789 0.043844 0

19.3 0.53827918 0.583752 0.314222 0.042285 0.015174 0.044568 0 19.3 0.53827918 0.583752 0.314222 0.042285 0.015174 0.044568 0 19.5 0.543857203 0.580505 0.315712 0.042926 0.015564 0.045294 0 19.7 0.549435225 0.577276 0.317176 0.043567 0.015958 0.046024 0 19.9 0.555013248 0.574065 0.318613 0.044209 0.016358 0.046756 0 20 0.557802259 0.572466 0.319323 0.04453 0.016559 0.047123 0 20 0.557802259 0.572466 0.319323 0.04453 0.016559 0.047123 0 20 0.557802259 0.572466 0.319323 0.04453 0.016559 0.047123 0 20 0.557802259 0.572466 0.319323 0.04453 0.016559 0.047123 0 20 0.557802259 0.572466 0.319323 0.04453 0.016559 0.047123 0 20.2 0.563380282 0.569281 0.320722 0.045172 0.016966 0.047858 0 20.2 0.563380282 0.569281 0.320722 0.045172 0.016966 0.047858 0 20.3 0.566169293 0.567696 0.321412 0.045493 0.017171 0.048227 0 20.4 0.568958304 0.566115 0.322096 0.045815 0.017378 0.048597 0 20.5 0.571747316 0.564538 0.322773 0.046136 0.017585 0.048967 0 20.5 0.571747316 0.564538 0.322773 0.046136 0.017585 0.048967 0 20.6 0.574536327 0.562966 0.323444 0.046458 0.017794 0.049338 0 20.7 0.577325338 0.561398 0.324109 0.046779 0.018005 0.049709 0 21 0.585692372 0.55672 0.326067 0.047744 0.018642 0.050827 0 21 0.585692372 0.55672 0.326067 0.047744 0.018642 0.050827 0 21 0.585692372 0.55672 0.326067 0.047744 0.018642 0.050827 0 21 0.585692372 0.55672 0.326067 0.047744 0.018642 0.050827 0 21 0.585692372 0.55672 0.326067 0.047744 0.018642 0.050827 0 21.1 0.588481383 0.55517 0.326707 0.048065 0.018857 0.051201 0 21.3 0.594059406 0.552082 0.327969 0.048708 0.01929 0.05195 0 21.5 0.599637429 0.549011 0.329207 0.049351 0.019729 0.052702 0 21.6 0.60242644 0.547482 0.329817 0.049673 0.019949 0.053079 0 22 0.613582485 0.541408 0.332198 0.050958 0.020845 0.054592 0 22 0.613582485 0.541408 0.332198 0.050958 0.020845 0.054592 0 22 0.613582485 0.541408 0.332198 0.050958 0.020845 0.054592 0 22 0.613582485 0.541408 0.332198 0.050958 0.020845 0.054592 0 22 0.613582485 0.541408 0.332198 0.050958 0.020845 0.054592 0 22.2 0.619160508 0.538396 0.333354 0.0516 0.021299 0.055351 0 22.2 0.619160508 0.538396 0.333354 0.0516 0.021299 0.055351 0 22.3 0.621949519 0.536897 0.333923 0.051921 0.021528 0.055732 0 22.3 0.621949519 0.536897 0.333923 0.051921 0.021528 0.055732 0 22.5 0.627527541 0.53391 0.335043 0.052562 0.02199 0.056495 0 23.2 0.647050621 0.523588 0.338788 0.054803 0.02364 0.059181 0 23.4 0.652628643 0.520675 0.339808 0.055442 0.024122 0.059953 0 23.5 0.655417654 0.519225 0.340309 0.055761 0.024365 0.06034 0 23.6 0.658206666 0.517779 0.340806 0.05608 0.024608 0.060727 0 23.7 0.660995677 0.516337 0.341297 0.056399 0.024853 0.061115 0 23.9 0.6665737 0.513465 0.342262 0.057036 0.025346 0.061892 0 24 0.669362711 0.512035 0.342737 0.057354 0.025594 0.062281 0 24 0.669362711 0.512035 0.342737 0.057354 0.025594 0.062281 0 24 0.669362711 0.512035 0.342737 0.057354 0.025594 0.062281 0 24 0.669362711 0.512035 0.342737 0.057354 0.025594 0.062281 0 24.1 0.672151722 0.510609 0.343207 0.057672 0.025843 0.06267 0 24.2 0.674940734 0.509187 0.343671 0.057989 0.026093 0.06306 0 24.3 0.677729745 0.507768 0.34413 0.058307 0.026344 0.063451 0 24.5 0.683307767 0.504944 0.345032 0.058941 0.02685 0.064233 0 25 0.697252824 0.497951 0.347198 0.060521 0.028132 0.066197 0 25 0.697252824 0.497951 0.347198 0.060521 0.028132 0.066197 0 25.1 0.700041835 0.496565 0.347616 0.060836 0.028392 0.066591 0 25.5 0.71119788 0.491056 0.349238 0.062094 0.029441 0.068172 0 26.5 0.739087993 0.477549 0.352951 0.065215 0.032133 0.072151 0 27 0.75303305 0.470936 0.35463 0.066762 0.033516 0.074155 0 27 0.75303305 0.470936 0.35463 0.066762 0.033516 0.074155 0 27 0.75303305 0.470936 0.35463 0.066762 0.033516 0.074155 0 27.7 0.772556129 0.461831 0.35679 0.06891 0.035491 0.076977 0 27.7 0.772556129 0.461831 0.35679 0.06891 0.035491 0.076977 0 28.7 0.800446242 0.449128 0.359503 0.071941 0.03839 0.081038 0 28.8 0.803235253 0.447878 0.359751 0.072241 0.038684 0.081446 0 28.8 0.803235253 0.447878 0.359751 0.072241 0.038684 0.081446 0 29.6 0.825547343 0.437995 0.361586 0.074627 0.041072 0.084721 0 33.4 0.931529773 0.393951 0.366977 0.085462 0.053074 0.100536 0 34.5 0.962208897 0.382048 0.36761 0.088429 0.056725 0.105187 0

Mann-Whitney U Test Mann-Whitney U Philips Length (cm) Own Length (cm) N: 122 117 Mean rank: 86.996 33.004

Mann -Whitn U 985 z 11.516 Monte Carlo permutation: p (same med.) 1.09-30 p (same med.) 0.0001

Ordinary Least Squares Figure 28: Apex-Aperture Length Slope a 0.55694 Intercept b 2.2828 Std. error a 0.13539 Std. error b 0.91068 95% bootstrapped confidence intervals (N=1999) Slope a (0.089785, .92722) Intercept b (-0.081161, .0811) Correlation r 0.32529 r2 0.10581 t 4.1136 p (uncorrected) 0.0000651 Permutation p 0.0003 Slope 0.55694 Intercept: 2.2828

Figure 29: Whorl Length Slope a 0.35 Intercept b -0.85773 Std. error a 0.049878 Std. error b 0.99529 95% bootstrapped confidence intervals (N=1999) Slope a (0.24823, 0.45542) Intercept b (-2.6757, 0.88486) Correlation r 0.5061 r2 0.25613

49 t 7.017 p (uncorrected) 0.000000000083723 Permutation p 0.0001 Slope 0.35 Intercept: -0.85773 Normality Scores Figure 13: Field Glycimeris Length (cm) N 117 Shapiro-Wilk W 0.954 p(normal) 0.0005143 Anderson-Darling A 1.732 p(normal) 0.0001836 p(Monte Carlo) 0.0002 Jarque-Bera JB 6.908 p(normal) 0.03162 p(Monte Carlo) 0.0366 N 117 Min 0 Max 4.8 Sum 282.1 Mean 2.411111 Std. error 0.1122131 Variance 1.473238 Stand. Dev 1.21377 Median 2.2 25 prcntil 1.4 75 prcntil 3.5 Skewness 0.3407181 Kurtosis -0.9723418 Geom. mean 0 Coeff. var 50.34069

Figure 12: Museum Glycimeris Length (cm) N 122 Min 1.5 Max 8 Sum 589.9 Mean 4.835246 Std. error 0.09425959 Variance 1.083954 Stand. dev 1.041131 Median 4.9 25 prcntil 4.3 75 prcntil 5.5

Skewness -0.2255953 Kurtosis 0.9907962 Geom. mean 4.708461 Coeff. var 21.53212

Log Whorl Figure 17: Field Neptunea Length (cm) N 34 Shapiro-Wilk W 0.9219 p(normal) 1.83E-02 Anderson-Darling A 0.8562 p(normal) 2.48E-02 p(Monte Carlo) 0.0206 Jarque-Bera JB 3.187 p(normal) 2.03E-01 p(Monte Carlo) 0.0854 N 34 Min -0.05129329 Max 2.949688 Sum 67.40592 Mean 1.982527 Std. error 0.1364284 Variance 0.632832 Stand. dev 0.7955074 Median 2.180401 25 prcntil 1.371431 75 prcntil 2.613719 Skewness -0.7545026 Kurtosis -0.2823459 Geom. mean 0 Coeff. var 40.12593

Figure 19: Museum Neptunea Log Whorl Length (cm) N 411 Shapiro-Wilk W 0.9106 p(normal) 7.41E-15 Anderson-Darling A 11.48 p(normal) 1.31E-27 p(Monte Carlo) 0.0001 Jarque-Bera JB 161.3 p(normal) 9.58E-36 p(Monte Carlo) 0.0001 N 411 51

Min 0 Max 3.861151 Sum 1078.324 Mean 2.62366 Std. error 0.02896056 Variance 0.3447114 Stand. dev 0.5871213 Median 2.80336 25 prcntil 2.24071 75 prcntil 3.034953 Skewness -1.217553 Kurtosis 1.916768 Geom. mean 0 Coeff. var 22.37795

Figure 16: Broken Neptunea Field Log Length (cm) N 36 Shapiro-Wilk W 0.9287 p(normal) 0.02291 Anderson-Darling A 0.8082 p(normal) 0.03298 p(Monte Carlo) 0.034 Jarque-Bera JB 3.146 p(normal) 0.2074 p(Monte Carlo) 0.0912

Figure 15: Broken Neptunea Museum Log Length (cm) N 36 Min -0.05129329 Max 2.949688 Sum 71.0612 Mean 1.973922 Std. error 0.1299808 Variance 0.6082207 Stand. dev 0.7798851 Median 2.180401 25 prcntil 1.405742 75 prcntil 2.608225 Skewness -0.7284514 Kurtosis -0.2600676 Geom. mean 0 Coeff. var 39.50941

Appendix 3. Data Tables Neptunea contraria Field Collection Number Apex-Aperture Whorl Length Scar 1 (from Scar 2 (from Scar 3 (from Scar 4 (from Locality (Collection) Length (cm) (cm) Apex) Apex) Apex) Apex) Bucknay BF1 5.9 18.9 0 0 0 0 Farm Bucknay BF2 0.99 2.3 0 0 0 0 Farm Bucknay BF4 2.65 6.5 0 0 0 0 Farm Bucknay BF5 2.01 5.9 0 0 0 0 Farm Bucknay BF6 6 15 0 0 0 0 Farm Bucknay BF7 2.19 8.9 0 0 0 0 Farm Bucknay BF8 2 17 0 0 0 0 Farm Bucknay BF9 1.84 1.9 0 0 0 0 Farm Bucknay BF10 0.7 0.95 0 0 0 0 Farm Bucknay BF11 3.88 16.2 0 0 0 0 Farm Bucknay BF12 1.43 6.8 0 0 0 0 Farm Bucknay BF12 0.7 2.9 0 0 0 0 Farm Bucknay BF13 0.6 2 0 0 0 0 Farm Bucknay BF14 2.47 8.4 0 0 0 0 Farm Bucknay BF15 2.4 11.5 0 0 0 0 Farm Bucknay BF16 1.9 11.5 0 0 0 0 Farm Q1 3 9.5 0 0 0 0 Quarry Q2 1.5 0 0 0 0 0 Quarry Q3 6.6 19.1 0 0 0 0 Quarry Neutral NF1 1.4 4.4 0 0 0 0 Farm Neutral NF2 1 3.5 0 0 0 0 Farm Neutral NF3 2.2 4.1 0 0 0 0 Farm Neutral NF4 3 10.5 0 0 0 0 Farm Neutral NF5 1 2.3 0 0 0 0 Farm Neutral NF9 0 4.7 1.5 0 0 0 Farm W1 7.4 18.4 0 0 0 0 Walton W2 5.6 12 0 0 0 0 Walton W3 5.9 9.9 0 0 0 0 Walton W4 4.1 8.8 0 0 0 0 Walton W5 3 7.5 0 0 0 0 Walton W6 5.2 12.3 0 0 0 0 Walton BA1 5.7 13.8 0 0 0 0 Bawdsey BA2 4.7 13.5 0 0 0 0 Bawdsey Bucknay BF17 5.3 13.6 0 0 0 0 Farm Bucknay BF18 0.3 18 0 0 0 0 Farm Bucknay BF19 0.6 3.5 0 0 0 0 Farm

Museum Collections Whorl Scar 1 Scar 2 Scar 3 Scar 4 Apex-Aperture Number (Collection) Length (from (from (from (from Notes Length (cm) (cm) Apex) Apex) Apex) Apex) Box TN 554.16 ( Cannon & 3 7.6 3.6 2 BORED Brookes Collection) Box TN 554.16 ( Cannon & 6.4 20 3.5 7 Brookes Collection) 6846 6.8 19.4 4 7 13.6 18.6

45135 3.6 9.8 2.9 8.8

43925 2.6 6.6 2.3 9.2

Box TN 554.16 ( Cannon & 3.3 9.6 2.8 9.2 Brookes Collection) Box TN4292 (Cambridge 5.2 16.7 9.3 10 Collection) 45857 4.8 11.1 10.1 10.6

43957 6.2 16.8 5.8 12

Box TN4292 (Cambridge 4.1 12.2 7.2 12.2 16.2 Collection) 6848.2 6 15 12.1 13

Box TN4292 (Cambridge 5.6 16.8 9 13.2 Collection) Box TN4292 (Cambridge 5.6 14 12.3 13.5 Collection) Box TN4292 (Cambridge 4.9 18.5 12.6 13.7 Collection) Box TN4292 (Cambridge 5.1 17 8.5 14 Collection) Box TN4292 (Cambridge 5.1 16 12 14 Collection) 43914 7 18.5 9 14.3 16

45858 4.5 15.4 13.8 15

Box TN4292 (Cambridge 6 17 16 16.7 Collection) Box TN4292 (Cambridge 5.3 17.2 14.1 16.8 Collection) Box TN4292 (Cambridge 6 20.8 4.2 17.7 Collection) 43955 6.4 18.6 14.5 18.1

Box TN4292 (Cambridge 5.9 20 15.6 18.8 Collection) Box TN4292 (Cambridge 8.1 27.2 12 19 Collection) Box TN4292 (Cambridge 7.2 23.2 14.5 19 Collection) 44486 1 36.9 14.1 21 27 35

Box TN4292 (Cambridge 6.5 23.5 16.2 21 Collection) Box TN4292 (Cambridge 4.6 24.9 10 22.9 Collection) 45846 19.3 47.52 17.3 25.7

43928 22.3 32.1 28 30

45847 17.5 43 26 31

54447 1.1 4 1.9

Box TN4292 (Cambridge 2.6 6.5 2 Collection) Box TN4292 (Cambridge 6.1 20 2.3 Collection) Box TN 554.16 ( Cannon & 2.7 4.4 2.4 Brookes Collection) 45107 3.9 10.4 2.4

Box TN4292 (Cambridge 4.7 15.9 2.4 Collection) 45122 11.4 3.1 2.6

44341 2.7 10 2.6

Box TN4292 (Cambridge 5.6 20 3 Collection) Box TN 554.16 ( Cannon & 2.2 8.2 3.5 Brookes Collection)

Box TN4292 (Cambridge 5.1 16.9 3.5 Collection) Box TN 554.16 ( Cannon & 1.2 4.1 3.9 Brookes Collection) 43915 7.4 25.6 3.95

Box TN 554.16 ( Cannon & 4.6 14.4 4.4 Brookes Collection) Box TN4292 (Cambridge 7 24 4.7 Collection) 45136 3.4 10.1 4.8

43948 4.8 13 5.2

Box TN4292 (Cambridge 7.4 24.2 5.5 Collection) 43946 5.4 13.5 5.6

43947 3.5 12.6 6

43948 3.5 12.5 6.1

Box TN 554.16 ( Cannon & 3.3 9 6.4 Brookes Collection) 43926 2.8 7.5 6.6

Box TN 554.16 ( Cannon & 2.3 7.5 6.7 Brookes Collection) 45131 9.5 25.9 6.7

Box TN4292 (Cambridge 5.9 20 7 Collection) 43924 3.6 9 7.3

Box TN 554.16 ( Cannon & 2.34 8.3 7.75 Brookes Collection) Box TN4292 (Cambridge 6.5 20.7 8 Collection) Box TN 554.16 ( Cannon & 3.1 8.9 8.4 Brookes Collection) 43937 4.7 14 8.4

Box TN4292 (Cambridge 5 17.3 8.4 BROKEN Collection) 43921 5.2 18 8.4

Box TN 554.16 ( Cannon & 3 9.4 8.8 Brookes Collection) Box TN4292 (Cambridge 2.4 11.4 9.5 Collection) Box TN4292 (Cambridge 4.9 15.5 9.99 Collection) 43918 5.4 12.6 10

Box TN4292 (Cambridge 5.5 17.6 10 Collection) Box TN4292 (Cambridge 7.3 24.6 10 Collection) 43931 3.8 11.2 10.1

7382 6.9 14.2 10.1

Box TN4292 (Cambridge 7.5 24.1 10.1 Collection) Box TN4292 (Cambridge 5.4 16.2 10.2 Collection) Box TN 554.16 ( Cannon & 4.5 14.2 10.6 Brookes Collection) 43938 4.9 11.5 10.8

Box TN4292 (Cambridge 5.4 17.1 10.8 Collection) 43942 7.69 20 11

Box TN4292 (Cambridge 6.6 21.1 11 BROKEN Collection) 45880 3.9 14.4 11.1

Box TN4292 (Cambridge 6 21.2 11.1 Collection) Box TN4292 (Cambridge 5.4 18.1 11.1 Collection) 43940 4.1 12.7 11.3

43941 7 18 11.7

Box TN 554.16 ( Cannon & 4.2 13.3 11.8 Brookes Collection) 10001 6 17.8 12

43923 5.2 13.5 12.1

Box TN4292 (Cambridge 5.4 17.4 12.1 Collection)

Box TN 554.16 ( Cannon & 5.6 19.2 12.3 BORED Brookes Collection) Box TN 554.16 ( Cannon & 4.8 15.8 12.4 Brookes Collection) 47657 5.3 13.5 12.5

Box TN4292 (Cambridge 6 19.3 12.5 Collection) 43911 8.5 22.5 12.5

Box TN4292 (Cambridge 7.1 23 12.5 Collection) 47655 7.9 19.8 12.6

Box TN4292 (Cambridge 6.2 20 12.6 Collection) Box TN4292 (Cambridge 5.5 20.1 12.7 Collection) 43930 1.2 31.5 12.9

Box TN4292 (Cambridge 7 24.4 13 Collection) Box TN4292 (Cambridge 4.7 18.5 13.4 Collection) Box TN4292 (Cambridge 7.6 24 13.6 Collection) 45656 6 14 13.8

47651 7.4 16 13.9

43991 9.7 23.7 14.1

45138 6 15.8 14.2

45126 8.2 23.4 14.2

Box TN4292 (Cambridge 5 17.2 14.7 Collection) 10002 6.9 19 14.9

Box TN4292 (Cambridge 5.4 15.4 15 Collection) 45859 8.5 22.5 15.5

Box TN 554.16 ( Cannon & 5.5 18.7 15.8 Brookes Collection) Box TN4292 (Cambridge 6.9 20.9 15.9 Collection) Box TN4292 (Cambridge 6.7 20.6 15.9 Collection) Box TN4292 (Cambridge 5.3 17 16 Collection) 7346 7.5 18.5 16.2

Box TN4292 (Cambridge 7.3 24.6 16.3 Collection) Box TN4292 (Cambridge 8 24 16.9 Collection) Box TN4292 (Cambridge 7 22.1 17 Collection) 43961 7.8 23.8 17

Box TN4292 (Cambridge 6 19.65 17.2 Collection) Box TN4292 (Cambridge 5.8 20.8 17.3 Collection) 42929 8 23.6 17.5

Box TN 554.16 ( Cannon & 8.3 25.6 17.5 Brookes Collection) 43906 6.9 20.6 17.8

Box TN4292 (Cambridge 4.8 21 18 Collection) 43913 8.2 23 18

Box TN4292 (Cambridge 6.7 22.6 18.2 Collection) 64335 9 26 18.5

45124 9.7 28.6 18.6

Box TN4292 (Cambridge 6 22 19.1 Collection) Box TN4292 (Cambridge 6.6 23.8 19.1 Collection) Box TN4292 (Cambridge 7.3 24 19.4 Collection) Box TN4292 (Cambridge 7 21 19.5 BROKEN Collection)

Box TN4292 (Cambridge 6 21.4 19.6 Collection) 44585 7.4 25.9 19.6

Box TN4292 (Cambridge 6.1 21 20 Collection) Box TN4292 (Cambridge 6.7 21.5 20 Collection) 53939 11 23 20

Box TN4292 (Cambridge 7 25 20.4 Collection) Box TN4292 (Cambridge 6 21 20.5 Collection) 43908 10.1 27.9 20.8

Box TN4292 (Cambridge 7 23.5 21 Collection) Box TN4292 (Cambridge 8.4 24.5 22 Collection) Box TN4292 (Cambridge 9.3 31.5 23.1 Collection) 43960 11.8 38.5 25.6

44330 7.6 2

54448 0.9 2

Box TN 554.16 ( Cannon & 1.2 2 Brookes Collection) 43905 8.9 2.6

Box TN 554.16 ( Cannon & 1.1 2.6 Brookes Collection) 45123 9 3.1

Box TN 554.16 ( Cannon & 1.1 3.1 Brookes Collection) 54446 1.9 3.3

Box TN 554.16 ( Cannon & 1.4 3.3 Brookes Collection) 54449 0.8 3.7

Box TN 554.16 ( Cannon & 1.5 3.9 Brookes Collection) Box TN 554.16 ( Cannon & 1.5 4 Brookes Collection) Box TN 554.16 ( Cannon & 1.9 4.1 Brookes Collection) 43936 1.4 4.3

Box TN 554.16 ( Cannon & 1.6 4.8 Brookes Collection) Box TN 554.16 ( Cannon & 1.6 4.8 Brookes Collection) Box TN 554.16 ( Cannon & 1.8 4.8 Brookes Collection) Box TN4292 (Cambridge 4.9 4.8 Collection) Box TN 554.16 ( Cannon & 1.7 5 Brookes Collection) 44590 3.1 5.1

Box TN 554.16 ( Cannon & 1.6 5.1 Brookes Collection) Box TN 554.16 ( Cannon & 17.4 5.5 BORED Brookes Collection) Box TN 554.16 ( Cannon & 2.1 5.5 Brookes Collection) 6854 2.6 5.6

Box TN 554.16 ( Cannon & 2.2 5.6 Brookes Collection) 44331 2.2 5.8

44589 2.5 5.8

Box TN 554.16 ( Cannon & 1.5 5.9 Brookes Collection) Box TN 554.16 ( Cannon & 1.5 5.9 Brookes Collection) 6848.1 2.4 6

45130 2.2 6

Box TN 554.16 ( Cannon & 2 6 Brookes Collection) Box TN 554.16 ( Cannon & 1.7 6 Brookes Collection)

Box TN 554.16 ( Cannon & 1.7 6.2 BORED Brookes Collection) Box TN 554.16 ( Cannon & 3 6.2 Brookes Collection) Box TN 554.16 ( Cannon & 1.5 6.3 Brookes Collection) Box TN 554.16 ( Cannon & 3 6.5 Brookes Collection) Box TN 554.16 ( Cannon & 2.2 6.5 Brookes Collection) Box TN 554.16 ( Cannon & 2.6 6.5 Brookes Collection) 43929 2.5 6.6

43930 3 6.6

43965 2.4 6.6

Box TN 554.16 ( Cannon & 2.4 6.6 Brookes Collection) Box TN 554.16 ( Cannon & 2.4 6.6 Brookes Collection) 45139 2.4 6.7

43935 2.2 6.8

45932 2.4 6.8

Box TN 554.16 ( Cannon & 2.5 6.8 Brookes Collection) Box TN 554.16 ( Cannon & 2.4 6.9 Brookes Collection) 44732 2.5 7

Box TN 554.16 ( Cannon & 2.4 7 Brookes Collection) Box TN 554.16 ( Cannon & 3.2 7 Brookes Collection) 43934 3.7 7.2

Box TN 554.16 ( Cannon & 3 7.2 Brookes Collection) Box TN 554.16 ( Cannon & 2.3 7.2 Brookes Collection) 43967 2.5 7.3

Box TN 554.16 ( Cannon & 2.5 7.3 Brookes Collection) Box TN 554.16 ( Cannon & 3.6 7.4 Brookes Collection) Box TN 554.16 ( Cannon & 2.4 7.4 Brookes Collection) 43928 3.1 7.5

Box TN 554.16 ( Cannon & 2.3 7.5 Brookes Collection) 6856 2.7 7.8

43932 2.5 7.9

Box TN 554.16 ( Cannon & 2.3 7.9 Brookes Collection) 45106 3 8

Box TN 554.16 ( Cannon & 2.6 8 Brookes Collection) Box TN 554.16 ( Cannon & 2.7 8 Brookes Collection) Box TN 554.16 ( Cannon & 2.9 8.1 Brookes Collection) Box TN 554.16 ( Cannon & 3.4 8.1 Brookes Collection) 43927 2.4 8.2

Box TN 554.16 ( Cannon & 3 8.2 Brookes Collection) 6857 2.2 8.3

Box TN 554.16 ( Cannon & 3.6 8.3 Brookes Collection) 43920 3 8.4

Box TN 554.16 ( Cannon & 3 8.4 Brookes Collection) Box TN 554.16 ( Cannon & 3.4 8.6 BORED Brookes Collection) 44333 2 8.8

Box TN 554.16 ( Cannon & 2.45 8.8 Brookes Collection)

Box TN 554.16 ( Cannon & 3.5 8.9 BROKEN Brookes Collection) #VALUE! 2.5 9

Box TN 554.16 ( Cannon & 3 9 Brookes Collection) Box TN 554.16 ( Cannon & 3 9.2 Brookes Collection) Box TN 554.16 ( Cannon & 3.7 9.3 Brookes Collection) 44334 2.4 9.4

46651 4.8 9.4

Box TN 554.16 ( Cannon & 3.7 9.4 Brookes Collection) Box TN 554.16 ( Cannon & 3.3 9.6 Brookes Collection) Box TN 554.16 ( Cannon & 2.9 9.9 Brookes Collection) #VALUE! 2.6 10

Box TN4292 (Cambridge 3.9 10 Collection) 43916 5.2 10.4

Box TN4292 (Cambridge 3.5 10.4 Collection) Box TN 554.16 ( Cannon & 4 10.7 Brookes Collection) Box TN4292 (Cambridge 3 10.8 Collection) 44342 2.4 11

Box TN 554.16 ( Cannon & 3 11 Brookes Collection) Box TN 554.16 ( Cannon & 3.5 11 Brookes Collection) 43949 5.5 11.3

45137 4 11.3

Box TN 554.16 ( Cannon & 4.4 11.4 Brookes Collection) 45134 4.5 12

43943 5.2 12.1

Box TN 554.16 ( Cannon & 4 12.3 BORED Brookes Collection) 43919 4.5 12.5

Box TN 554.16 ( Cannon & 4.4 12.5 BROKEN Brookes Collection) Box TN4292 (Cambridge 4 12.5 BORED Collection) Box TN 554.16 ( Cannon & 4.5 12.8 Brookes Collection) #VALUE! 4 13

Box TN 554.16 ( Cannon & 3.9 13 Brookes Collection) Box TN4292 (Cambridge 3.9 13 Collection) Box TN4292 (Cambridge 4.6 13 Collection) Box TN 554.16 ( Cannon & 3.9 13.1 Brookes Collection) 43866 4.6 13.3

Box TN4292 (Cambridge 3.9 13.3 Collection) 43958 5 13.5

Box TN 554.16 ( Cannon & 4.7 13.6 Brookes Collection) Box TN4292 (Cambridge 4.6 13.6 Collection) 43953 6 13.9

Box TN4292 (Cambridge 4 13.9 Collection) #VALUE! 4.8 14

43947 5.4 14.1

Box TN4292 (Cambridge 3.8 14.2 Collection) Box TN 554.16 ( Cannon & 5 14.4 Brookes Collection)

43937 4.4 14.5

Box TN4292 (Cambridge 4.2 14.5 Collection) Box TN4292 (Cambridge 4.8 14.8 Collection) 43964 5.6 14.9

Box TN4292 (Cambridge 5 14.9 Collection) 45133 7.4 15

47653 7.7 15

Box TN 554.16 ( Cannon & 5.7 15 Brookes Collection) Box TN 554.16 ( Cannon & 4.5 15 Brookes Collection) Box TN4292 (Cambridge 4.6 15 Collection) Box TN4292 (Cambridge 5 15 Collection) Box TN4292 (Cambridge PARTIAL 4.2 15.1 Collection) BREAK Box TN4292 (Cambridge 5.1 15.1 Collection) Box TN4292 (Cambridge 5 15.1 Collection) Box TN4292 (Cambridge 5 15.2 Collection) Box TN4292 (Cambridge 4.6 15.2 Collection) 43962 5.6 15.3

Box TN4292 (Cambridge 4.8 15.3 Collection) 45132 6.2 15.4

Box TN4292 (Cambridge 5 15.5 Collection) 43945 5.7 16

Box TN4292 (Cambridge 5.3 16 Collection) Box TN4292 (Cambridge 4.5 16 Collection) 47654 6.6 16.1

Box TN4292 (Cambridge 5.5 16.1 Collection) Box TN4292 (Cambridge 5 16.1 Collection) Box TN4292 (Cambridge 4.8 16.1 Collection) Box TN4292 (Cambridge 5.9 16.2 Collection) Box TN4292 (Cambridge 3.2 16.2 Collection) 45850 7.3 16.5

Box TN 554.16 ( Cannon & 5 16.5 Brookes Collection) Box TN4292 (Cambridge 4.8 16.5 Collection) Box TN4292 (Cambridge 5.4 16.8 Collection) 6872 7.9 17

43951 6.9 17

Box TN4292 (Cambridge 5 17 Collection) Box TN4292 (Cambridge 5.3 17.1 Collection) Box TN4292 (Cambridge 5.2 17.14 Collection) 43863 5 17.2

43999 6 17.2

47658 6 17.2

Box TN4292 (Cambridge 6 17.3 Collection) Box TN4292 (Cambridge 5 17.3 Collection)

Box TN4292 (Cambridge 5.2 17.4 Collection) 47652 5.4 17.5

Box TN4292 (Cambridge 5.1 17.5 Collection) 6867 8.2 17.6

Box TN4292 (Cambridge 6.4 17.6 Collection) Box TN4292 (Cambridge 5.5 17.6 Collection) Box TN4292 (Cambridge 6.2 17.7 Collection) Box TN4292 (Cambridge 5.6 17.8 Collection) Box TN 554.16 ( Cannon & 6 18 Brookes Collection) Box TN 554.16 ( Cannon & 5.1 18 Brookes Collection) Box TN4292 (Cambridge 6 18 Collection) Box TN4292 (Cambridge 5.9 18 Collection) Box TN4292 (Cambridge 5.7 18.1 Collection) Box TN4292 (Cambridge 5.1 18.1 Collection) Box TN4292 (Cambridge 5.9 18.2 BROKEN Collection) Box TN4292 (Cambridge 5.3 18.2 Collection) Box TN4292 (Cambridge 5.5 18.3 Collection) Box TN4292 (Cambridge 5.6 18.5 Collection) Box TN4292 (Cambridge 5.7 18.5 Collection) Box TN4292 (Cambridge 6.4 18.6 Collection) Box TN4292 (Cambridge 6.2 18.6 Collection) Box TN4292 (Cambridge 5 18.7 Collection) Box TN4292 (Cambridge 6 18.7 Collection) Box TN4292 (Cambridge 5.7 18.8 Collection) 43922 7.4 19

43956 7.3 19

45127 9 19

Box TN 554.16 ( Cannon & 6.3 19 Brookes Collection) Box TN4292 (Cambridge 7 19 Collection) Box TN4292 (Cambridge 5.9 19 Collection) Box TN4292 (Cambridge 6.2 19.1 Collection) Box TN4292 (Cambridge 5.5 19.1 Collection) 6868 6.3 19.3

43910 7.6 19.3

Box TN4292 (Cambridge 6 19.5 BORED Collection) Box TN4292 (Cambridge 6.5 19.7 Collection) Box TN4292 (Cambridge 5.6 19.9 Collection) 47650 7.6 20

48530 7.4 20

Box TN 554.16 ( Cannon & 6.2 20 Brookes Collection) Box TN4292 (Cambridge 6.7 20 BROKEN Collection)

Box TN4292 (Cambridge 6.3 20 Collection) Box TN 554.16 ( Cannon & VERY 5.4 20.2 Brookes Collection) BROKEN Box TN4292 (Cambridge 6.2 20.2 Collection) Box TN 554.16 ( Cannon & 8 20.3 Brookes Collection) Box TN4292 (Cambridge 6.2 20.4 Collection) 43944 6 20.5

Box TN4292 (Cambridge 6.1 20.5 Collection) Box TN4292 (Cambridge 6.5 20.6 Collection) 6853 7.1 20.7

45116 8 21

45129 6.5 21

Box TN4292 (Cambridge 6.2 21 Collection) Box TN4292 (Cambridge 6.1 21 Collection) Box TN4292 (Cambridge 6.2 21 Collection) Box TN 554.16 ( Cannon & 7.9 21.1 Brookes Collection) Box TN4292 (Cambridge 6.5 21.3 Collection) Box TN4292 (Cambridge 7.5 21.5 Collection) 43952 7.9 21.6

Box TN4292 (Cambridge 7 22 Collection) Box TN4292 (Cambridge 6.5 22 Collection) Box TN4292 (Cambridge 6 22 Collection) Box TN4292 (Cambridge 7.5 22 Collection) Box TN4292 (Cambridge 6.5 22 Collection) 43950 8.4 22.2

Box TN4292 (Cambridge 6 22.2 Collection) Box TN4292 (Cambridge 7.3 22.3 BROKEN Collection) Box TN4292 (Cambridge 6.5 22.3 Collection) Box TN4292 (Cambridge 6.5 22.5 Collection) Box TN4292 (Cambridge 6.1 23.2 Collection) Box TN4292 (Cambridge 7.3 23.4 Collection) Box TN4292 (Cambridge 6.2 23.5 Collection) 48531 9.6 23.6

Box TN4292 (Cambridge 7 23.7 BORED Collection) 47649 8.1 23.9

43917 7.8 24

Box TN4292 (Cambridge 7.3 24 Collection) Box TN4292 (Cambridge 7.8 24 Collection) Box TN4292 (Cambridge 8 24 Collection) Box TN4292 (Cambridge 7.2 24.1 Collection) Box TN4292 (Cambridge 7 24.2 Collection) 43909 7.6 24.3

Box TN4292 (Cambridge 8.5 24.5 BORED Collection) 43912 7.9 25

45855 9.7 25

Box TN4292 (Cambridge 8 25.1 Collection) 43954 7 25.5

43941 8.5 26.5

6842 10.5 27

6843 1 27

45854 9.6 27

Box TN4292 (Cambridge 8 27.7 Collection) Box TN4292 (Cambridge 8.2 27.7 Collection) Box TN4292 (Cambridge 7.5 28.7 Collection) 45128 8 28.8

Box TN4292 (Cambridge 6.6 28.8 Collection) Box TN4292 (Cambridge 8.6 29.6 Collection) Box TN4292 (Cambridge 8.2 33.4 BROKEN Collection) 43907 10.7 34.5

Glycimeris glycimeris Field Collection Box Length (cm) Height (cm) LOCALITY NOTES BF1 3 Bucknay Farm

BF2 3.4 Bucknay Farm

BF3 4 2 Bucknay Farm

BF4 3.4 Bucknay Farm

BF5 3.1 2 Bucknay Farm

BF6 1 2.6 Bucknay Farm

BF7 1.2 2.4 Bucknay Farm

BF8 1.7 1.8 Bucknay Farm

BF9 0.9 Bucknay Farm BORED

BF10 1.6 2.7 Bucknay Farm

BF11 1.5 Bucknay Farm

BF12 2.8 Bucknay Farm

BF12 1.3 1.8 Bucknay Farm

BF13 0.9 Bucknay Farm

BF14 1.9 Bucknay Farm

BF15 1.5 1.7 Bucknay Farm

BF16 1.8 1.2 Bucknay Farm

BF17 1 1.3 Bucknay Farm

BF18 2.7 2.4 Bucknay Farm

BF19 3.5 3.7 Bucknay Farm

BF20 2 1.4 Bucknay Farm

BF21 2.4 1.8 Bucknay Farm BORED BF22 0.8 1.2 Bucknay Farm

BF23 1.1 0.9 Bucknay Farm

BF24 1.3 1.1 Bucknay Farm

BF25 1.1 Bucknay Farm

BF26 2 1.7 Bucknay Farm

BF27 1.3 1.9 Bucknay Farm

BF28 1.5 1.2 Bucknay Farm BORED BF29 1.6 1 Bucknay Farm

R1 2.6 1.7 Ramsholt

R2 1.8 1.4 Ramsholt

R3 1.7 1.6 Ramsholt

R4 2.8 2 Ramsholt

R5 3.2 2.2 Ramsholt

R6 2.3 Ramsholt

R7 2.7 Ramsholt

R8 1.5 Ramsholt

R9 2.5 Ramsholt

Q1 Quarry

Q2 Quarry

Q3 Quarry

Q4 Quarry

Q5 Quarry

Q6 Quarry

Q7 1.5 Quarry

Q8 11 Quarry

Q9 1.9 1.4 Quarry

Q10 1.8 Quarry

Q11 Quarry

Q12 4.8 Quarry

Q13 3.7 Quarry

Q14 2.2 1.6 Quarry

Q15 3.9 3.3 Quarry

Q16 4.6 Quarry

Q17 2 1.5 Quarry BORED Q18 4.1 3.3 Quarry

Q19 4.6 4.4 Quarry

Q20 4.6 4 Quarry

Q21 3.6 2.4 Quarry BORED Q22 1.8 1.6 Quarry

Q23 1.5 1.4 Quarry

Q24 0.7 0.6 Quarry

Q25 0.6 0.65 Quarry

Q26 0.5 0.4 Quarry

Q27 0.9 0.7 Quarry

Q28 0.9 0.8 Quarry

Q29 0.6 0.4 Quarry

Q30 1.1 0.8 Quarry

NF1 4 2.9 Neutral Farm

NF2 1.5 1.7 Neutral Farm

NF3 1.2 0.75 Neutral Farm

NF4 2.5 3.1 Neutral Farm

NF5 2 1.6 Neutral Farm

NF6 1.7 2.2 Neutral Farm

NF7 3 Neutral Farm

NF8 3 Neutral Farm

NF9 3.7 3.2 Neutral Farm

NF10 2.9 2.8 Neutral Farm

NF11 2.9 2.7 Neutral Farm

NF12 2.7 2.5 Neutral Farm

NF13 2.4 Neutral Farm

NF14 2.7 1.9 Neutral Farm

NF15 2.2 2.4 Neutral Farm

NF16 2.2 Neutral Farm

NF17 2.2 Neutral Farm

NF18 3.7 Neutral Farm

NF19 2.5 1.6 Neutral Farm

NF20 Neutral Farm BORED

NF21 3.6 Neutral Farm BORED

NF22 Neutral Farm

NF23 Neutral Farm

NF24 Neutral Farm BORED

NF25 Neutral Farm BORED

NF26 Neutral Farm

NF27 Neutral Farm

NF29 Neutral Farm

NF28 Neutral Farm

W1 4.5 4.3 Walton

W2 5.3 Walton

W3 5.2 Walton

W4 1.3 1.2 Walton

W5 1.2 1.1 Walton

W6 1.6 1.4 Walton

W7 1 0.9 Walton

W8 3.5 3.4 Walton

W9 2.7 2.5 Walton

W10 3.1 2.8 Walton

W11 3.5 3.2 Walton

W12 3.9 3.5 Walton

W13 3.5 3.3 Walton

W14 3.7 3.6 Walton

W15 4.3 4.1 Walton

W16 4.6 4.3 Walton

W17 4.5 4 Walton

W18 4.3 4 Walton

W19 4.2 3.9 Walton

W20 0 0 Walton

W21 1.1 Walton

W22 5 Walton

W23 4.2 Walton

W24 4.8 Walton

W25 4.8 4.7 Walton

W26 2.9 2.4 Walton

W27 1 0.7 Walton

W28 1 1.1 Walton

W29 1.2 1 Walton

W30 1.3 1.2 Walton

W31 2.1 1.7 Walton

BC1 3.3 3.2 Buckanay

BC2 2.1 1.6 Buckanay

BC3 0.8 0.7 Buckanay

BC4 1.1 0.9 Buckanay

BC5 1.1 Buckanay

BC6 2 1.6 Buckanay

BC7 2.3 2.2 Buckanay

BC8 1.7 1.7 Buckanay

BC9 1.7 1.3 Buckanay

BC10 1.6 1.5 Buckanay

BC11 2.2 2.1 Buckanay

BC12 2.7 Buckanay

BC13 1.6 Buckanay

BC14 1.5 Buckanay

BC15 1.7 Buckanay

BU1 4.1 3.8 Butley

BU2 1.3 1.1 Butley

BU3 3.7 Butley

BU4 2.9 Butley

BU5 4.2 Butley

BU6 3.2 Butley

Museum Collections Box Species Length (cm) Height (cm) NOTES TN4292 Glycimeris 6.5 6.7

TN4292 Glycimeris 8 7.7

TN4292 Glycimeris 5.2 5

TN4292 Glycimeris 7 6.7

TN4292 Glycimeris 5.4 5.4

TN4292 Glycimeris 4.4 4.3

TN4292 Glycimeris 5.7 4.8

TN4292 Glycimeris 4.7 4.4

TN4292 Glycimeris 4 3.9

TN4292 Glycimeris 6.5 6.4

TN4292 Glycimeris 5 4.8

TN4292 Glycimeris 6.5 6.1

TN4292 Glycimeris 5.7 5.5

TN4292 Glycimeris 4.2 4.8

TN4292 Glycimeris 4 4

TN4292 Glycimeris 4.4 4.3

TN4292 Glycimeris 5.3 5

TN4292 Glycimeris 3.2 2.8

TN4292 Glycimeris 4.8 5

TN4292 Glycimeris 4.8 4.8

TN4292 Glycimeris 4.3 4

TN4292 Glycimeris 3.3 3

TN4292 Glycimeris 5.2 5.3

TN4292 Glycimeris 4.7 4.2

TN4292 Glycimeris 5.8 5.8

TN4292 Glycimeris 2.6 2.4

TN4292 Glycimeris 2.7 2.5

TN4292 Glycimeris 5.9 5.9

TN4292 Glycimeris 5.5 5.8

TN4292 Glycimeris 4.6 4.3

TN4292 Glycimeris 5.2 4.8

TN4292 Glycimeris 5.5 5.6

TN4292 Glycimeris 6.6 6.3

TN4292 Glycimeris 5.2 5.1

TN4292 Glycimeris 4.5 4.3

TN4292 Glycimeris 5.6 5.2

TN4292 Glycimeris 5.5 4.9

TN4292 Glycimeris 5.5 5.4 BORED TN4292 Glycimeris 5.5 5.5

TN4292 Glycimeris 6.2 6.2

TN4292 Glycimeris 5.6 5.4

TN4292 Glycimeris 5.4 4.3

TN4292 Glycimeris 4.9 4.8

TN4292 Glycimeris 4 3.8

TN4292 Glycimeris 3.7 3.6

TN4292 Glycimeris 4.8 4.4

TN4292 Glycimeris 4.9 4.8

TN4292 Glycimeris 4.5 4.4

TN4292 Glycimeris 5.8 5.4

TN4292 Glycimeris 4.3 4

TN4292 Glycimeris 5.1 5.1

TN4292 Glycimeris 4 3.6

TN4292 Glycimeris 5 5.3

TN4292 Glycimeris 4.6 4.1

TN4292 Glycimeris 5.4 5.5

TN4292 Glycimeris 5.2 5.2

TN4292 Glycimeris 4.5 4.2

TN4292 Glycimeris 5.3 5.3

TN4292 Glycimeris 4.9 5

TN4292 Glycimeris 4.3 4.1

TN4292 Glycimeris 4.6 4.65

TN4292 Glycimeris 4.6 4.7

TN4292 Glycimeris 3.7 3.5

TN4292 Glycimeris 4.8 4.8

TN4292 Glycimeris 4 4

TN4292 Glycimeris 5 4.6

TN4292 Glycimeris 1.5 1.4

TN4292 Glycimeris 5.5 5.2

TN4292 Glycimeris 3 3

TN4292 Glycimeris 5 4.8

TN4292 Glycimeris 3.7 3.85

TN4292 Glycimeris 3.5 3.1

TN4292 Glycimeris 4.4 4.5

TN4292 Glycimeris 3.1 2.9

TN4292 Glycimeris 4.3 4.3

TN4292 Glycimeris 6.6 6.5

TN4292 Glycimeris 5.4 5.1 BORED TN4292 Glycimeris 5.1 4.7

TN4292 Glycimeris 4.7 4.6

TN4292 Glycimeris 4 4.1

TN4292 Glycimeris 5 4.9

TN4292 Glycimeris 4.4 4.2

TN4292 Glycimeris 4.8 4.5

TN4292 Glycimeris 5.3 4.8

TN4292 Glycimeris 5.1 5.1

TN4292 Glycimeris 7.2 6.8

TN4292 Glycimeris 4.1 4

TN4292 Glycimeris 4.7 4.4

TN4292 Glycimeris 5 4.9

TN4292 Glycimeris 2.9 2.4

TN4292 Glycimeris 3 2.8

TN4292 Glycimeris 3 3

TN4292 Glycimeris 5.8 5.7

TN4292 Glycimeris 6.8 6.5

TN4292 Glycimeris 6.4 6.2

TN4292 Glycimeris 4.5 4.4

TN4292 Glycimeris 4.9 4.5

TN4292 Glycimeris 5.8 5.5

TN4292 Glycimeris 5.2 5

TN4292 Glycimeris 4.5 4.3

TN4292 Glycimeris 4.3 4.3 BORED TN4292 Glycimeris 4.7 4.5

TN4292 Glycimeris 5.5 5.1

TN4292 Glycimeris 3 3.7

TN4292 Glycimeris 4.8 4.35

TN4292 Glycimeris 5.4 5.1

TN4292 Glycimeris 4.4 4.1

TN4292 Glycimeris 4.4 4.2

TN4292 Glycimeris 5.5 5.6

TN4292 Glycimeris 3.3 3

TN4292 Glycimeris 6 6

TN4292 Glycimeris 5 4.8

TN4292 Glycimeris 4.9 4.5

TN4292 Glycimeris 5 4.9

TN4292 Glycimeris 3.9 3.3

TN4292 Glycimeris 5.9 5.5

TN4292 Glycimeris 2.2 2.2

TN4292 Glycimeris 5 4.7

TN4292 Glycimeris 4.7 4.4

TN4292 Glycimeris 5.2 5.5

TN4292 Glycimeris 5.6 5.3

TN4292 Glycimeris 4.9 4.6

Appendix 4. Supplementary Data Presentation

25 Neptunea with at least one 20 measurement Frequencey 15 Glycimeris with at least one measurement 10

0 1 2 3 4 5 Taphonomic Index

Figure A Taphonomic Index Neptunea N=40, Glycimeris N=140; Index 1-5, 1=Very broken, 5=Undamaged

1,0 0,9 0,8 0,7 0,6 Frequencey 0,5 0,4 0,3 0,2 0,1 0,0 0 1 2 3 4 Scars per Indivdual

Figure B Poisson distribution for x̅ =0.4417. 0.4417= Number of scars per individual. x̅ =λ

Appendix 5. Supplementary Photographs

Figure C Butley(Broom Covert). Crossbeds ~2.25m high, scree beneath

Figure D Waldringfield Heath (Quarry). Exposure of working face

Figure E Neutral Farm Pit. Crossbeds ~5cm high

Examensarbete vid Institutionen för geovetenskaper ISSN 1650-6553