The Ability of Mosasaurs to Produce Unique Puncture Marks on Ammonite Shells

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THE ABILITY OF MOSASAURS TO PRODUCE UNIQUE PUNCTURE MARKS ON AMMONITE SHELLS

Steven Daniel King

A Thesis

Submitted to the Graduate College at Bowling Green

State University in partial fulfillment of

the requirements of the degree of

MASTER OF SCIENCE

August 2009

Committee:

Margaret Mary Yacobucci, Advisor

James Evans

Daniel Mark Pavuk

Steven Daniel King

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Abstract:

Margaret Mary Yacobucci, Advisor

The purpose of this study was to test the claim that certain types of unique puncture marks on ammonite shells could be produced by mosasaur bites. These unique puncture marks are double puncture marks, which are two adjacent holes set within the same indented rim, and puncture marks on only one flank of an ammonite’s shell. The common interpretation of puncture marks in ammonite shells is that they were bite marks from mosasaurs, however, this idea has been challenged, in part with the claim that these two unique types of puncture marks could not be produced by a mosasaur’s bite.

To answer this question, this study was divided into two parts. The first part involved measuring the position and orientation of teeth from 202 mosasaur jaw bones and jaw fragments to determine if any had teeth that were crooked enough that they would have tips that were adjacent to one another.

Additionally, the distribution and variety of tooth orientations were compared among several mosasaur genera. These comparisons were accomplished by performing univariate statistics using the PAST software package. The second part of this study was to build a replica of a mosasaur skull and use it to crush modern Nautilus shells, to see if puncture marks on only one side of a shell could be experimentally produced. The mosasaur Prognathodon overtoni was used as the model for this replica as this genus is thought to have been the mosasaur most likely responsible for the puncture marks on ammonite shells. The skull replica was made of steel and was used to crush twenty-two Nautilus shells.

The crushed shells were then examined and compared to ammonite puncture marks and previous tests in which Nautilus shells were crushed. The results of this study showed that there are a range of tooth orientations in mosasaurs and that in rare cases, adjacent teeth can be found whose tips are close enough to have produced double puncture marks. In addition, the skull replica succeeded in producing iv

puncture marks restricted to one flank of a Nautilus shell’s phragmocone when a partial bite force was applied. These results strengthen the claim that mosasaurs were responsible for the puncture marks found on ammonite shells.

Acknowledgments:

I would like to thank Dr. Richard and Mrs. Mary Ann Hoare for providing funding for this project through the Richard D. Hoare Research Scholarship. These funds were essential for providing transportation costs needed to travel to several museums to complete this study.

I would like to thank Caleb Cook for his help in creating the mosasaur skull replica. Caleb provided the necessary materials, tools, and abilities needed to take the skull replica from an idea to a physical model.

I would like to thank Charles Codding for permitting the use of and help in operating a Tinius-

Olsen press. This press was used to measure forces needed to crush Nautilus shells, which was a valuable part of this study.

Finally, I would like to thank Dr. Peg. Naturally, since she is my advisor, it would seem obvious that I would have to rely on her help, but I want to thank her for her guidance as I learned, and continue to learn how to properly do research.

Table of Contents:

1. Introduction 1

2. Background 2

3. Previous Tests 5

4. Research Objectives 8

5. Methods 8

6. Results 20

Tooth Morphometrics 20

Shell Crushing 22

7. Discussion 24

8. Conclusion 29

Works Cited 30

Appendix A: Tables of Tooth Measurements and Transformation to Bookstein

Coordinates 56

Appendix B: Description of Crushed Nautilus Shells 120

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Figures:

Figure Page

1. A Placenticeras specimen with puncture marks 32

2. Reconstruction of Tylosaurus, a common mosasaur 33

3. Example of a double puncture mark in an ammonite shell 34

4. Coordinate system for tooth morphometrics 35

5. Streptostyly in a mosasaur’s skull 36

6. Mandibular movement in a mosasaur’s jaw 37

7. Pattern used for the construction of the skull replica 38

8. The complete skull replica 39

9. Plot of complete and chipped tooth pairs for the maxilla 41

10. Plot of complete and chipped tooth pairs for the dentary 42

11. Plot of tooth tips in the dentary with convex hulls 45

12. Plot of tooth tips in the maxilla with convex hulls 46

13. Distance between the tips of the teeth in the tooth pairs 47

14. Tooth pair in a Platecarpus sp. whose teeth tips are very close to each other 48

15. Tooth pair in an unknown mosasaur whose tips are close to each other 49

16. New tooth occupying the same socket as an old tooth 50 viii

17. Crushed remains of dry Nautilus shells 51

18. Puncture marks on specimen 12 partway through crushing 52

19. Puncture marks on specimen 19 partway through crushing 52

20. Close up of a puncture mark made in a wet Nautilus shell 54

21. Close up of a puncture mark made in a dry Nautilus shell 55

B1. Orientations of skull used to crush shells 129

B2. Final results for specimen 1 130

B3. Final results for specimen 2 130

B4. Final results for specimen 3 131

B5. Final results for specimen 4 132

B6. Final results for specimen 5 133

B7. Final results for specimen 6 134

B8. Final results for specimen 7 134

B9. Final results for specimen 8 135

B10. Final results for specimen 9 136

B11. Final results for specimen 10 137

B12. Final results for specimen 11 138

B13. Specimen 12 partway through crushing 138 ix

B14. Final results for specimen 12 139

B15. Final results for specimen 13 140

B16. Specimen 14 partway through crushing 140

B17. Final results for specimen 14 141

B18. Specimen 15 partway through crushing 142

B19. Final results for specimen 15 142

B20. Final results for specimen 16 143

B21. Final results for specimen 17 143

B22. Final results for specimen 18 144

B23. Specimen 19 partway through crushing 144

B24. Final results for specimen 19 145

B25. Final results for specimen 20 145

Tables:

Tables Page

1. Experimental plan for the crushing of the wet Nautilus shells 40

2. Statistics for the distribution of the tooth tips in tooth pairs in the dentary 43

3. Statistics for the distribution of the tooth tips in tooth pairs in the maxilla 44

4. Results of bite force measurements 53

A1. Tooth measurements 58

A2. Complete and chipped adjacent tooth pairs 109

A3. Original coordinates and Bookstein coordinates for all tooth pairs in the dentary 113

A4. Original coordinates and Bookstein coordinates for tooth pairs in the maxilla and

premaxilla 116

A5. Calculations of the tooth tips in tooth pairs 119

Introduction:

Determining predator/prey relationships in the fossil record can be difficult. Sometimes, direct evidence of these sorts of relationships can be found, in the form of stomach contents, for instance.

One interesting type of evidence for predator/prey relationships that may be found in the fossil record is puncture marks found in ammonite shells. The first ammonite with puncture marks was described by

Kauffman and Kesling (1960). This ammonite was a Placenticeras from the Campanian Pierre Shale near

Scenic, South Dakota. This specimen had numerous puncture marks in the shell and part of the body chamber was crushed. Many of these puncture marks were in obvious rows and had matching rows on the opposite side, indicating that they were produced by some sort of predator. The presence of smaller tooth marks that appear to have been caused by pterygoid teeth led Kauffman and Kesling

(1960) to identify a mosasaur as the predator responsible, because mosasaurs were the only marine predators with pterygoid teeth in the Western Interior Seaway, which covered much of central North

America during the Late Cretaceous.

More ammonites have been found with puncture marks since that time. Additional

Placenticeras specimens with puncture marks have been found in the Bearpaw Formation (which is thought to be equivalent to the Pierre Shale) of Alberta (Hewitt and Westermann 1990 and Tsujita and

Westermann 1998) and the ammonite Sphenodiscus has been found with puncture marks in the Severn

Formation in Maryland (Bukowski and Bond 1989). Other types of ammonites, such as Baculites and

Metoicoceras, have been found with marks that may have been made by mosasaurs (Kauffman 1990).

However, this study will focus on puncture marks found in Placenticeras and Sphenodiscus as these are the two most common ammonites found with puncture marks. In addition, the marks on the

Metoicoceras specimen indicate that the predator was a Globidens (Kauffman 1990), a mosasaur with rounded, blunt teeth that appears to have been a crushing specialist, whereas the puncture marks in

Placenticeras and Sphenodiscus are typically round holes, indicating that the mosasaur that attacked 2

them had conical teeth (the more common style of mosasaur teeth). Placenticeras and Sphenodiscus specimens with puncture marks range from the Santonian to the Maastrichtian (Kauffman 1990) and they appear to be restricted to places that were once covered by the Western Interior Seaway. Figure 1 illustrates a typical Placenticeras specimen with puncture marks. Since their discovery and initial interpretation as bite marks made by mosasaurs, the puncture marks on ammonites have been considered a classic example of predator-prey interactions in the fossil record. However, this interpretation has been challenged by some who suggest that the puncture marks actually came about by a completely different phenomenon. The present study addresses specific aspects of this debate.

Background:

The ammonites Placenticeras and Sphenodicus both have similar types of body structure.

Placenticeras typically ranged in size from 20 to 50 cm in diameter, with a few attaining 1 m in diameter

(Tsujita and Westermann 1998). Both of these ammonites had narrow, disc shaped shells with an unornamented surface and appear to have been active swimmers (Kauffman 1990). Placenticeras has been interpreted as living in waters near the surface of the sea, where they may have been active predators themselves (Tsujita and Westermann 1998). Presumably, since Sphenodiscus had a similarly structured shell, it had similar habits and habitats. Living near the surface of the sea would likely have made them targets for active, air breathing predators such as the mosasaurs.

The mosasaurs are a group of extinct marine lizards. A reconstruction of a typical mosasaur is shown in Figure 2. There were around 20 genera of mosasaurs, spanning from the Turonian to the

Maastrichtian (Russell 1967, Everhart 2005). They are closely related to the living monitor lizards

(Family Varanidae) as well as to snakes. Similar to both varanids and snakes, the mosasaurs appear to have been predatory, having large, sleek skulls with sharp, usually conical, pointed teeth. Unlike varanids, however, they had many features that indicate that they were marine reptiles. They had 3

flippers (front and back pairs were similar to each other) and they had long, flattened tails. The mosasaurs were also very large: they ranged in size from 4 meters to over 15 meters long. All mosasaurs had a very conservative body plan: a long, fairly slender body with a large, fairly slender head

(Russell 1967, Everhart 2005). Although most mosasaurs were thought to have been general predators, there were some slight differences between the genera that indicate slightly different habits. Some, such as Clidastes, had long, narrow skulls, small flippers, and long bodies with a prominent fin on their tail. These types were thought to have been fast swimmers that chased down prey. Others, such as

Platecarpus, had shorter bodies, larger flippers, and shorter, more robust skulls. These types would have been slower swimmers but would have had greater agility. Others, such as Tylosaurus (Figure. 2), were intermediate in structure (Russell 1967). Then there is Globidens, which appears to have been the most specialized mosasaur, since instead of having pointed teeth, it had blunt, rounded teeth that appear to have been used for crushing shells (Russell 1967, Everhart 2005).

Mosasaurs were known to have eaten a wide variety of prey items. Some of the stomach contents found in mosasaurs include: fish, sharks, swimming birds, turtles, plesiosaurs, and other mosasaurs (Everhart 2005). Based on this wide variety of prey and the unspecialized body plan of most mosasaurs, these large reptiles appear to have been dietary generalists, eating just about anything.

With a few exceptions, such as Globidens, mosasaur teeth are unspecialized, being simple, curved spikes. These teeth would be useful in grabbing and holding prey but would not have been much use in cutting up or tearing prey.

There has been some speculation as to what species of mosasaur was responsible for the puncture marks in Placenticeras and Sphenodiscus. Kauffman and Kesling (1960) suggested that an unknown species of mosasaur was responsible for the puncture marks on the Placenticeras specimen that they described. They came to this conclusion because the angle between two rows of teeth was fairly large so the mosasaur must have had a wide skull. The mosasaur that they thought was probably 4

closest to the mosasaur responsible for the puncture marks was Platecarpus brachycephalus or

Ancylocentrum overtoni. According to Russell (1967), Platecarpus brachycephalus is a junior synonym of

Plioplatecarpus primaevus and Ancylocentrum is a junior synonym of Prognathodon overtoni. Later,

Kauffman (1990) suggested that different mosasaurs were responsible for different bite marks in ammonites. He suggested that different bite marks could be attributable to Mosasaurus, Tylosaurus,

Platecarpus, and possibly Clidastes. Kauffman (1990) does not fully explain how these different mosasaurs were identified as the ones responsible for the bite marks, except that he references

Kauffman and Kesling (1960) when identifying Platecarpus as the mosasaur responsible for the first ammonite with puncture marks found, and he discusses a second ammonite shell with puncture marks, this one with huge teeth marks. Based mainly on the size of the puncture marks, he concludes that the mosasaur responsible for the puncture marks on this specimen was probably a species of Mosasaurus, as the size of the marks slightly exceeded the size of the teeth of Mosasaurus horridus. Other authors

(Russell 1967 and Tsujita and Westermann 2001) suggest that the mosasaur responsible for most of the bites in ammonite shells was a species of Prognathodon. Russell (1967) based his conclusion on the shape of the puncture marks on the ammonite described by Kauffman and Kesling (1960). Tsujita and

Westermann (2001) simply said that Prognathodon was usually the mosasaur thought to have been responsible for the bite marks in ammonites. Following Russell (1967) and Tsujita and Westermann

(2001), it appears that the mosasaur that is the culprit for the puncture marks in ammonites is

Prognathodon, in most cases. For this reason, Prognathodon was the mosasaur on which this study focused.

Prognathodon was one of the larger mosasaurs. Its skull was about a meter long and it would have had a body length of around 9 meters. (These dimensions are rough estimates based on to-scale illustrations in Russell (1967)). Russell only illustrated the skull of Prognathodon, so the length of

Prognathodon was estimated by comparing the size of Prognathodon’s skull to the size of Tylosaurus’s 5

skull and comparing that ratio to the length of Tylosaurus.) The skull of Prognathodon is more heavily built than other mosasaurs (with the exception of Globidens). The maxillary is larger and the teeth are more robust (Russell 1967). Three species of Prognathodon were present in North America during the mid-Campanian to the Maastrichtian (Everhart 2005). While a relatively rare mosasaur, it has been found in the Pierre Formation in Kansas and South Dakota, in the Navesink Formation in New Jersey

(Russell 1967), the Lewis Shale of Colorado (Kues and Lucas 1985), and the Bearpaw Formation of

Alberta (Massare 2006). Because of its heavy jaws, it appears that Prognathodon may have been capable of puncturing or crushing ammonite shells. Also, its stratigraphic and geographic ranges coincide with many of the locations where ammonites with puncture marks have been found (Pierre

Formation and Bearpaw Shale), so it is reasonable that this may be the genus of mosasaur most likely responsible for many of the puncture marks. However, it could not have been responsible for all of them, since puncture marks first appear in the Santonian while Prognathodon does not appear in North

America until the Campanian.

Previous Tests:

The idea that mosasaurs were responsible for the puncture marks in ammonites was challenged by Kase et al. (1998). They suggested that limpets (a type of algae-grazing snail) were responsible for the puncture marks. In their model, limpets would be living on the dead and floating shells of

Placenticeras. The limpets would exhibit homing behavior, that is, they would habitually rest on the same spot on the shells. As the limpets continually rested on the same spots, the limpets would leave home scars on the ammonite’s shell (produced by the shells of the limpets abrading against the shell of the ammonite). Upon burial and compaction, the home scars would produce a weak spot that would be broken out of the shell, leaving a circular to elliptical hole. 6

Kase et al. (1998) supported this idea using several reasons. First, limpet shells have been found as fossils stuck on Placenticeras shells. In addition, radular grazing marks of limpets have also been found on Placenticeras shells. These two points show that limpets did make their homes on presumably deceased ammonite shells. Second, Kase et al. (1998) performed an experiment where robotic mosasaur jaws were used to create puncture marks in fresh Nautilus shells (no exact description of the nature of the shells at the time the experiment was conducted, they were just described as fresh). The robotic jaws in this experiment consisted of steel jaws with brass teeth driven by compressed air. These robotic jaws produced bite forces ranging from 6346 N to 10,974 N. While these bite forces are high, they fall within the measured bite forces of modern alligators, which range from 217 N to 13,172 N

(Erickson et al. 2004). In the trials performed by Kase et al. (1998), the Nautilus shells either fractured or the puncture marks left angular edges. Neither of these patterns have been found on ammonite shells with supposed bite marks. Third, Kase et al. (1998) claim that the pattern of puncture marks on ammonite shells is not consistent with the idea that they were bitten by a mosasaur. In 72 specimens that they examined, only 12 had puncture marks lined up and matching on both sides, four had holes seen only on one side of the shell, and the rest had no clear pattern of puncture marks. Additional types of puncture marks that Kase et al. (1998) said are inconsistent with the mosasaur hypothesis are twin holes (adjacent holes connected to one another with a single depression rim around them, Figure 3) and puncture marks on the surface that do not penetrate to the septa below.

Tsujita and Westermann (2001) responded to Kase et al. (1998). Tsujita and Westermann (2001) point out that the puncture marks that Kase et al. (1998) made with their robotic mosasaur jaws on modern Nautilus were actually fairly consistent with puncture marks in ammonites. This is because many puncture marks found on ammonites are not perfect circles or ellipses: some have rough edges and corners. It is true that none are as angular as the punctures made on the Nautilus shell but Tsujita and Westermann (2001) point out that according to the limpet hypothesis, all of the puncture marks 7

should be round and none should be angular at all. In addition, they point out that the structure of an ammonite’s shell is different from that of Nautilus. The ammonite shell has complexly folded septa while the septa on Nautilus are simple. Tsujita and Westermann (2001) claim that this would have made the ammonite’s shell more elastic so that it would not shatter and produce angular holes as in a

Nautilus’s shell. Tsujita and Westermann (2001) also point out that circular dents in the shell of ammonites, that is, puncture marks that have not been completely broken through, do not match the expected pattern if they were caused by limpet home scars, either. A limpet home scar would leave a circular ring of abrasion; it would not produce a dent.

Tsujita and Westermann (2001) also remarked about the possibility of mosasaurs being able to produce twin holes and sets of holes on one flank of a shell only. They speculate that twin holes could be produced either by crooked teeth, so that two adjacent teeth are bent toward one another or by an old tooth and a new, replacement tooth growing up in the same socket (this latter case does occur during the ontogeny of tooth replacement according to Caldwell 2007). Other variations of puncture marks could also be made by damaged teeth. As for puncture marks produced on one side of the shell only, Tsujita and Westermann speculate that this could be explained in several ways. First of all, it could be caused by having more teeth in contact with the shell on one side, thus spreading the force more evenly. This arrangement would result in the pressure being low enough on each tooth so that none would break through while on the other side, fewer teeth in contact with the shell would mean that there was greater pressure on each tooth, so that the teeth break through on that side. A second suggestion is that the teeth on one side of the shell might impact on the umbilical shoulder of the shell.

This area is thought to be the strongest part of the shell and would thus resist breaking while the teeth on the other side will break through.

It is perhaps worth noting that it is possible that puncture marks on ammonites were produced by both mosasaurs and limpets. Even though they strongly dispute the claim that all puncture marks on 8

ammonites are the result of limpet home scars, Tsujita and Westermann (2001) acknowledge the possibility that some puncture marks were caused by limpets. This point that two different organisms

(mosasaurs and limpets) could produce similar marks may be better emphasized if the puncture marks on ammonites are initially viewed as trace fossils, as it is an important principle that multiple organisms can produce the same trace fossils.

Research Objectives:

I propose to investigate whether the suggestions made by Tsujita and Westermann (2001) about the twin holes and the puncture marks found on one side of the shell are feasible. Specifically, this study tests the idea that twin holes could have been produced by mosasaurs either by crooked, adjacent teeth or by an old tooth and its replacement tooth occupying the same position, and it tests the idea that a mosasaur could produce puncture marks on only one side of an ammonite’s shell.

Methods:

This research was divided into two parts. The first part involved a morphometric study of mosasaur teeth to evaluate the plausibility of twin puncture marks. To do this, a system was devised to note the position of the base of each tooth and the tip of each tooth. For the teeth in the dentary

(lower jaw), a line that passes through the bases of the first and last teeth was considered to be the x- axis. The base of the tooth is defined as the middle of the socket right at the dorsal surface of the dentary (unlike most squamates, mosasaurs have teeth with roots that are set in sockets, Caldwell

2007). This way, the position of the base of a tooth may be defined by the position of the socket in case a tooth is missing. Figure 4 shows how this coordinate system works. The base of the posterior-most tooth was considered to be the origin for the coordinate system. The bases and tips of all the teeth were measured using a pair of steel rulers. A 40 cm long ruler was held from the base of the anterior 9

and posterior-most teeth and the x-coordinate was read off of it while a 15 cm ruler was used to measure the distance to the tooth tip or base from the former ruler to get the y-coordinate

Measurements were taken to the nearest millimeter. For teeth with damaged or broken tips, the tip was considered to be on the most distal part on the midline of the tooth. Any damage to a tooth was noted. The base and tip of newly erupted teeth were also noted, even if those teeth were occupying a socket that still had the old tooth in it. A similar system was used for the teeth in the premaxillary and maxillary (upper jaw): the base of the posterior-most maxillary tooth was considered the origin and the x-axis ran from there through the base of the anterior-most premaxillary tooth. The position of the base and tip of each tooth was noted in reference to this coordinate system and broken and damaged teeth were dealt with in the same manner as that described above. The purpose of this system of noting the position of the base and tip of each tooth is to allow the measurements to be graphed on a chart. In this way, the variability of mosasaur teeth, such as how much the horizontal difference between the tip and base of each tooth differs, can be easily visualized. These measurements should show if mosasaur teeth could have produced twin punctures in ammonite shells.

Three museums were visited to collect measurements of mosasaur teeth. These were the

Peabody Museum of Natural History at Yale University (designation YPM for specimens housed at this museum), the American Museum of Natural History (designation AMNH), and the University of Kansas

Museum of Natural History (designation KU). These museums were chosen because it was known that they had large collections of mosasaur specimens. In all, 121 mosasaur specimens were measured. In total, there were 202 jaw parts and jaw fragments measured (in this case, a jaw part refers to either one dentary or one premaxilla and maxilla, since each of these were measured individually).

Representatives of five genera were measured (Clidastes, Mosasaurus, Platecarpus, Prognathodon, and

Tylosaurus) plus several unknown mosasaurids. Multiple genera were examined, photographed, and measured because the genus that was the initial focus of this study, Prognathodon, is rare (only one 10

specimen was measured in this study) and to allow for some comparison between the different genera.

The bulk of the measurements came from Clidastes, Platecarpus, and Tylosaurus.

A few complications occurred while measuring the teeth bases and tips that necessitated adjustments to the methods as outlined above. First of all, most of the teeth in the jaws were broken. It was expected that there would be broken teeth but they were far more frequent than predicted. For the most part, these teeth broke after burial. This was determined because most of them had a mold of the internal cavity of a tooth but the tooth had broken around the mold. The measuring system for the teeth was capable of taking broken or missing teeth into account, but some jaws were not measured if all of their teeth were broken down to short stubs (relative to the size of the jaw, but typically from 2 mm for small mosasaurs like Clidastes to 15 mm for large mosasaurs like Tylosaurus). Teeth this short were thought to not provide any useful information, since even if an extrapolation was made from them, the extrapolation would have to extend 5 or 6 times beyond the actual measurement, making them very uncertain. Another problem was that many jaws were in fragments. In fact, there were very few complete jaws available to be measured. To compensate, in these jaw fragments, the x-axis ran through the base of the first and last teeth on the fragment and the origin was defined as the base of the posterior-most tooth. The curvature of the teeth allowed identification of which end of the fragment was posterior and which was anterior. Finally, post-mortem distortion of the jaws had to be taken into account. This was accomplished by visual inspection: if the jaw was bent out of the typical shape of a mosasaur’s jaw or if there was distortion of the matrix around the jaw (for those specimens that were imbedded in matrix), no measurement was taken. One exception to this rule was that, in a few cases, the teeth were visibly bent toward the lingual side of the jaw. This typically occurred when the teeth in one dentary were lying on top of, and distorted against, the opposite dentary. In these cases, the teeth did not appear to be bent either to the front or the back, and as the measurements were taken just in the plane of the length of the jaw, the distortion of these teeth was deemed to have 11

affected the relevant measurements only minimally. One ironic aspect of distortions that was noted is that distortions typically occurred in complete skulls. This bias in deformation was because the skulls were typically crushed and flattened, while jaw fragments experienced only minimal distortion. Thus, very few complete rows of teeth were measured.

To evaluate how the distance between adjacent teeth varies, coordinates for adjacent teeth were extracted from the data and assembled into a table by themselves. Only those pairs where both teeth were complete or chipped (chipped was used to describe teeth where the last millimeter or two of the tip was missing and as only a tiny bit was missing, they were considered to be complete enough to include in this analysis) were used. These data for tooth pairs (totaling 115 pairs) were then converted to Bookstein coordinates using the Bookstein (2D) transformation in PAST (PAleontological STatistics) software (Hammer, Harper, and Ryan 2008). The result of this transformation is to set the distance between the bases of the teeth in a pair to be equal among all the pairs, with coordinates (0,0) and (1,0) in arbitrary units. In this way, size differences are factored out, leaving only shape variation. These tooth pairs were then plotted as landmarks on PAST to visually compare the distribution of the tips in the tooth pairs.

It was initially intended that broken teeth would be extrapolated to their original tip. However, this extrapolation was not done because there was too much variability in the shape of mosasaur’s teeth. It was observed that there was a lot of variability of the orientation of a tooth, so extrapolating the location of the tips of broken teeth would be highly uncertain, even within a single taxon. Thus, no extrapolations were performed. Instead, only the tooth pairs of complete and chipped teeth were used.

Univariate statistics of the x- and y-coordinates of the tooth tips in a pair were performed using the PAST software so that the mean and standard deviation of the different genera could be compared.

So that both teeth in the tooth pairs could be compared to each other for these statistics, the x- coordinate (in Bookstein coordinates) of the tip of the second tooth in a pair (the one whose base was at 12

(1,0)) was subtracted by one. This calculation allowed both teeth in the pair to have a horizontal displacement of their tips relative to zero. All of the tooth pairs were modified this way and complied into a table. Univariate statistics of the x-coordinates were performed on this set of data. In a separate calculation, the distance between the tips of a pair was calculated and then plotted on PAST to check for any pairs that had tips that were abnormally close to each other. Abnormally close tips were identified as outliers on the lower end of the graph. There were a few outliers on the higher end of the graph, but as these were tooth tips that were unusually far apart, they were not of primary interest. The abnormally close tips, however, would be likely candidates for producing double puncture marks and of great interest for the current study.

The second part of this study required building a replica of a mosasaur’s jaws and using them to crush modern Nautilus shells in order to test experimentally whether puncture marks could be made on one side of the shell but not on the other. Several factors in developing this model needed to be addressed. The first is what type of mosasaur should be used as the model for the replica. Based on the previous research discussed above, the genus Prognathodon appears to be the most likely candidate for the mosasaur responsible for most of the ammonite punctures. Prognathodon overtoni is the species of

Prognathodon from North America that has the most described skull material, so it was chosen as the basis for the skull replica.

The second factor that needed to be addressed is the extent of movement that should be allowed in the skull. A mosasaur’s skull can flex in three different ways. The first is cranial kinesis. This motion occurs when the muzzle unit of the skull flexes up or down relative to the occipital unit of the skull (Russell 1967). Cranial kinesis is not present in all mosasaurs, Prognathodon being one of those that does not have it (Russell 1967), so it is not relevant to this model. The second type of skull flexing is streptostyly (Figure 5). Streptosyly refers to the ability of the quadrate to pivot about the quadrate cotylus of the paroccipital process. This movement allows the lower jaw to be jutted forward or pulled 13

back relative to the upper jaw (Russell 1967). The third type of flexing in mosasaur skulls occurs in the mandible (Figure 6). The mandible is divided into two halves that are joined near the center of the ventral margin of the mandible at the splenial-angular contact (Russell 1967). This allows the anterior half of the mandible to be elevated or deflected relative to the posterior half.

The third factor that needs to be addressed is the usefulness of Nautilus shells as an analog for an ammonite shell. As was mentioned in the previous section, Tsujita and Westermann (2001) pointed out that ammonites probably had a different degree of flexibility and strength in their shells than

Nautilus does. This difference in flexibility and strength results from a difference in shell thickness and septal structure. The shell of Placenticeras was thinner than that of Nautilus (Tsujita and Westermann

2001 and Hewitt and Westermann 1990). The thinner walls of the ammonite’s shell may have made them more elastic than those of Nautilus (Tsujita and Westermann 2001). The septa of ammonites are much more complex than those of Nautilus and it is often thought that this would have made the shells of ammonites stronger. It should be noted that there is some controversy as to how the complexly folded septa of ammonites affected the strength of their shells. One side claims that the septal pattern strengthened the shell. Therefore, it is reasoned that the more complexly folded the septa are, the deeper an ammonite could live before it imploded (Hassan et al. 2002). The other side claims the opposite, that increasing septal complexity actually weakens the shell and limits the depth to which ammonites could live (Daniel et al. 1997). However, the study by Daniel et al. (1997) concluded that septal complexity limited the depth ammonites could live in because it weakened the last formed septum, not necessarily the whole shell. They even suggest that the purpose of the folded septa may be to reduce the risk of shell breakage from predator attacks. Not only did the complexly folded septa increase the strength of the shell of ammonites, it is also thought to have made the shell more flexible compared to Nautilus (Hewitt and Westermann 1990). So for the purposes of this study, it will be considered that a Nautilus shell is weaker and less flexible than the shell of an ammonite. However, as 14

the focus of this research is to see whether the position and distribution of a mosasaur’s teeth could affect the pressure applied by the teeth and whether that could cause the teeth to puncture on one flank of the shell only, the difference in strength and flexibility between a Nautilus shell and an ammonite shell may not be significant.

A second aspect of the comparison of Nautilus and an ammonite is the overall shape of the shell. While ammonites as a group have a very wide range of shell shapes, the ammonite most frequently found with puncture marks is Placenticeras (Kauffman 1990, Tsujita and Westermann 2001).

Placenticeras is a flat, disc shaped ammonite. In comparison, Nautilus is much wider, particularly across the body chamber, meaning that not only was the shell of Nautilus more domed than the shell of

Placenticeras, the proportional width of the body chamber to phragmocone was also different. This certainly would change the number of teeth that could impact on the shell. Unfortunately, Nautilus is the only living analog to Placenticeras. It may be possible to create a cast of a Placenticeras shell and use that in a test such as this. However, such a replica would likely not duplicate some of the critical structures (such as septa) that a real Placenticeras shell would have. Therefore, even though Nautilus has a less than ideal shape for being an analog to Placenticeras, it was considered to be the best available analog.

A third concern was whether a dry Nautilus shell would behave in a more brittle fashion than the shell of a living Nautilus or ammonite. Certainly, a living Nautilus or ammonite shell (particularly the body cavity) would be partially supported by the body and the shell would be wet and permeated by organic material giving more support to the minerals in the shell. Truly fresh Nautilus shells would be very difficult to obtain so modern dried Nautilus shells were used. To compensate for the presence of a body and the dryness of the shell, the Nautilus shells used were soaked in water before they were crushed and the body cavity was filled with modeling clay. Organic material was not compensated for in this experiment. A partial reason why is because, without having access to fresh (that is, recently 15

deceased so that organic material is still present) Nautilus shells, some other type of shelled organism that is more easily obtained, such as a bivalve, would have to be tested instead. While this would give a qualitative comparison between a fresh versus a dried shell, it would not be known how that difference would translate to a Nautilus shell, as the shell structure between a Nautilus and a bivalve is very different. Additionally, testing with wet shells produced results that are similar to the puncture marks in ammonite shells. These bite marks in wet shells are more similar to the puncture marks in ammonite shells than the bite marks produced by Kase et al. (1998), who argued that their bite marks were too angular, suggesting that the rounded puncture marks on ammonite shells could not have been produced by mosasaur bites. This argument appears to have been sufficiently answered without needing to compare fresh versus dried bivalve shells and attempting to extrapolate that difference to a Nautilus shell.

The replica skull was constructed to be 0.4 scale of a Prognathodon overtoni skull. It was made at 0.4 scale because that was approximately the scale difference between a Nautilus (average diameter of specimens used: 12 cm) and a Placenticeras (average diameter: 30 cm). A diameter of 30 cm for

Placenticeras is toward the lower end of the range given by Tsujita and Westermann (1998), as they gave the typical range for the diameter of Placenticeras meeki to be from 20 to 50 cm. The pattern for the replica was obtained by copying the Prognathodon overtoni skull in Figure 90 in Russell (1967) (this is the same illustration that was the basis for Figure 4 of this work). Figure 7 shows the pattern that was used for the construction of the skull. This pattern consists of four basic pieces: upper jaw, mandible, dentary, and quadrate.

It was decided that the model skull would be constructed from steel. Constructing the skull out of steel was done as a matter of convenience: it was an easily obtainable and workable material and a friend had access to tools that would be needed to construct a skull out of sheet metal. Additionally, costs were a concern as all available funding for the project had been used before the skull was 16

constructed. Steel is also a suitable material for comparison to other studies that have used model mosasaur jaws. Kase et al. (1998) used steel jaws in their experiment and Schulp (2005) use a polyurethane resin, which had a hardness similar to brass.

The skull was made out of 3/8th inch thick steel sheets. The design shown in Figure 7 was cut out of these steel sheets using a plasma table. Two copies of each piece were cut out. In addition, two extra dentaries were cut. These dentaries were identical in design to the other two except that in one, the fourth tooth was missing and in the other, the tenth tooth was missing. The holes for the screws were then drilled out with a drill press. The teeth were ground down to points using a grinder. The result was that the teeth were pyramidal in shape, that is, they had a square cross-section. Making the teeth pyramidal was not ideal, as Prognathodon actually had conical teeth. However, none of the available tools would have been able to fit between the teeth so as to grind them into a conical shape.

The two pieces of the skull and the two pieces of the dentary were welded together at their anterior tips at an angle of approximately 30o. The two dentaries with missing teeth were welded together in a similar manner. The dentary with the 10th missing tooth was on the right side and the dentary with the fourth missing tooth was on the left side. The posterior tips of both sides of the skull and both sides of both dentaries were then bent to be parallel with each other. The final construction then consisted of seven pieces: one upper jaw, a pair of quadrates, a pair of mandibles, one dentary pair that had all of its teeth, and one dentary pair with two teeth missing. These pieces were then held together with screws.

The anterior end of the mandibles were fitted inside the posterior end of the dentaries, the lower end of the quadrates were on the outside of the posterior end of the mandibles, and the tops of the quadrates with inside of the posterior of the upper jaw. The primary concern with this arrangement was that the dentaries and upper jaw occluded against each other when the mouth was closed, the other pieces were fit around that design. The dentaries could be swapped out, so that tests could be done with 17

either a dentary with a full compliment of teeth or a dentary with two teeth missing. A completed picture of the replica is given in Figure 8.

The Nautilus shells used in this study were Nautilus pompilius purchased from Ward’s Natural

Science online. These shells averaged 12.3 cm in diameter and 6.5 cm at the widest point across their aperture. In total, 22 Nautilus shells were crushed. All of these shells were placed in the jaws with their aperture toward the front and the back of the shell toward the back of the mouth. The reason for this orientation was because mosasaurs were thought to have attacked ammonites from behind, approaching in the ammonite’s blind spot (Kauffman and Kesling 1960).

The shell of a Nautilus was always oriented in the jaws with the aperture toward the front, though the position varied with the aperture sometimes directed directly forwards and other times angled to the side. The exact orientation of the shell was often determined by how well it sat in the jaws (when the shell was first placed in the jaws and the replica’s mouth closed, the Nautilus shell would often rotate under the weight of the upper jaw) though in some cases, a specific orientation was intended to change the number of teeth in contact with the shell or to place a specific part of the shell

(such as positioning the umbilicus under a tooth). For simplicity’s sake, the directions of the Nautilus shells were set relative to its orientation in the replica’s mouth: the right side of the shell is the side that was on the right side of the skull, the top of the shell is the part that was directed toward the top of the skull, and so on. A shell was typically placed in the mouth so that the shell was centered between the second and seventh teeth in the dentary. In some trials, the shell was placed in a different location in the jaws (more to the posterior or more to the anterior) to test other conditions.

Two of the Nautilus shells were dry and they were crushed without any kind of preparation, while the other 20 were prepared before they were crushed. To prepare these 20 shells for crushing, they were submerged in tap water for seven days. The shells were then removed from the water and the body cavity was filled with modeling clay. The shell was then placed between the jaws and crushed, 18

while the shell was still wet. Crushing was accomplished by placing a vice at the anterior tip of the skull and lower jaw and tightening the vice. Placing the vice at the anterior tip was out of necessity rather than design: it was originally intended to use two vices and to have one on either side of the skull, either over the back of the skull where the actual jaw muscles would have been or directly over the Nautilus shell. However, the vices would not remain in place, but would slip off during compression.

The vice was a small vice that was screwed tight by hand. The vice was tightened at a slow rate; crushing a shell to completion often took around 15 seconds of uninterrupted compression. The rate of tightening was variable as the shell and jaws were being observed during tightening and the process was sometimes stopped in order to more closely examine the state of the shell before it was completely crushed. Crushing was ended after several holes, including one or two large (3-5 mm wide) holes, were present in the phragmocone. The body chamber had always been crushed at this point.

Before a shell was crushed, the skull was set to a particular degree of streptostyly and mandibular flexure. The skull was set by tightening down the joints between the quadrates and the upper jaw and the dentary and the mandibles. Streptostyly and mandibular flexing may have been dynamic during feeding. Streptostyly in particular is thought to have been used in manipulating and cutting prey (Russell 1967). Indeed, some ammonite shells have grooves on them that are thought to have been caused by the retractions of a mosasaur’s mandible (Kauffman and Kesling 1960 and Tsujita and Westermann 2001). However, it was decided for this study that the degree of streptostyly and mandibular flexing would remain fixed so that the only types of marks made on the Nautilus shells would be puncture marks resulting from the teeth being driven into the shell. Streptostyly and mandibular flexing were varied, from one experimentation to another, in order to change the distribution and position of the teeth. Even though it was intended that streptostyly and mandibular flexing would be fixed during the crushing of a shell, sometimes the force needed to crush the shell was great enough that tight joints would bend unintentionally. 19

The purpose of crushing the 20 wet shells was to see if it were possible to produce puncture marks on one flank of the shell but not on the other. Therefore, the experimental plan for crushing the

Nautilus shells changed during the course of the experiments so as to focus on those conditions that appeared most likely to produce the puncture marks on only one flank of the shell. The first several trials were systematic, focusing on protracting and retracting the mandible. The amount of protraction and retraction varied from one set of trials to another. This variance was not intentional but was because it was difficult to set the replica skull to a specific amount of protraction or retraction. The results of these trials indicated that streptostyly by itself did not effect whether puncture marks were produced on one flank only, so streptostyly was not varied much from that point on. In a similar manner, elevating the dentaries did not produce the puncture marks on one flank only so that condition was not tried often. The dentaries were never depressed as such a condition might push the shell out of the mouth as it was being closed. The dentaries with missing teeth were used much less often because they were just used to determine what the effect of missing teeth was, other variables (streptostyly and mandibular flexing) were held constant. This plan did not cover every possible combination of conditions, but it did succeed in identifying certain conditions that produced puncture marks on only one flank of a Nautilus’s shell. The entire experimental plan for the crushing of the twenty wet shells is shown in Table 1.

Force measurements were made separately after the rest of the shells had been crushed. Six shells were used, and these shells were soaked in tap water for six days and their body cavities filled with clay immediately prior to crushing. Soaking these shells for six days, rather than seven as in the previous 20 wet shells, was done due to time constraints. Force measurements were made by placing the replica skull, with a Nautilus shell in its jaws, in a Tinsius-Olsen press. The jaws were placed in the press so that the force of the press was applied to the jaws directly over the location of the Nautilus shell. The jaws were then compressed by the press at a slow rate (total time of compression was around 20

30 seconds) until the teeth of the model had penetrated the shell to the same depth as it had in the previous 20 wet shells. The amount of penetration was determined visually. When the teeth had penetrated the shell to the proper depth, the force on the press was released and the maximum amount of force applied was recorded. A variety of different shell orientations and placements in the jaws were used in order to reflect the various orientations of the 20 previous shells. After the bite forces were measured, bite pressure (stress) was calculated by dividing the force by the area of teeth in contact with the shell.

Results:

Tooth Morphometrics:

A complete list of the coordinates of all specimens measured, the coordinates of the complete and chipped tooth pairs, and their conversion to Bookstein coordinates are given in Appendix A. The tooth pairs plot for the teeth in the maxilla is shown in Figure 9 and the plot for the teeth in the dentary is shown in Figure 10. In total, there were 115 tooth pairs plotted on these graphs. Table 2 shows the statistics for the x- and y-coordinates of the teeth in the dentary of the different mosasaur genera.

Table 3 shows the statistics for the x- and y-coordinates of the teeth in the maxilla of the different mosasaur genera. Figures 11 and 12 show the distribution and convex hulls for tooth tips in the dentary and maxilla, respectively. Figures 11 and 12 use the table from which the statistics were derived, which is the table that was corrected so that the base of every tooth was at (0,0). Figure 13 shows the distance between the tips of the teeth in a pair.

Some generalizations can be made about the distribution of tooth tips among the different mosasaur genera. First of all, the variation (as seen in the standard deviation) along the x-axis is less than the variation along the y-axis. The only exception is the unknown in the dentary and this could be a result of a small sample size (there are only four teeth in this category) or because it may be a mixture of 21

genera. In general, the teeth of Platecarpus are more variable than the other genera, and in the case of the dentary, the teeth of Platecarpus are more variable than the total of all the teeth. This is relevant to the current study, because with its greater variation of teeth orientations, Platecarpus would be a likely candidate for producing double puncture marks.

In Figure 13, there are two outliers that are noteworthy. One is near the bottom with a distance of 0.1 (unitless) between adjacent tooth tips. This is by far the pair that is closest to each other. A picture of this specimen (KUM 85586), a Platecarpus, is shown in Figure 14. The actual horizontal (along the x-axis) distance between the tips of these two teeth is 1 mm. In comparison, the height of these teeth are 9 mm. The other notable outlier is significantly higher at 0.46 (unitless). A picture of this specimen (YPM 2062), an unknown genus, is shown in Figure 15. The actual distance between these tips of these two teeth is 22 mm. In comparison, the height of these teeth are 31 mm. These teeth pairs are significant because they may be able to produce double puncture marks. The literature does not give an indication of how close puncture marks have to be in order to be considered double puncture marks.

Kase et al. (1998) denote double puncture marks as two punctures within the same sloped rim and

Tsujita and Westermann (2001) just note that some holes occur in distinct pairs. The tooth pair in KUM

85586 would almost certainly have produced double puncture marks and their tips are only a millimeter apart. In fact, they might have produced a single hole. It is less certain whether the tooth pair in YPM

2062 could have produced double puncture marks: if they were to have punched holes in an ammonite shell, they would have produced holes noticeably closer to each other than other puncture marks though they may not have been within the same rim.

Another type of adjacent teeth that was noted in this study were new teeth occupying the same socket as an older tooth. As is noted in Appendix A, tooth pairs of this kind were observed but they were removed from the tables and graphs because their proportions were vastly different from the other tooth pairs, disallowing a proper comparison. Two of these pairs are shown in Figure 15 (YPM 22

2062), an unknown genus, and Figure 16 (AMNH 134), a Tylosaurus nepaeolicus. These would have produced a different kind of double puncture mark, where one hole was noticeably larger than the adjacent hole. This type of double puncture mark was described by Tsujita and Westermann (2001). It should be noted that other new teeth occupying the same socket as an older tooth were observed.

However, many of these were not measured because the new tooth was so small, it only extended past the jaw bone a millimeter or two.

Shell Crushing:

The two dry shells that were crushed are shown in Figure 17. The results of crushing the twenty wet shells are described and photographs are shown in Appendix B. The two dry shells shattered when crushed: one of them (which consisted of just the phragmocone, the body chamber having been destroyed previously) shattered into multiple pieces while the second (which had an intact body chamber) also shattered, though its pieces were still interlocked. This result is significant, because in the twenty other shells, all of which were wet when they were crushed and all but one of which had clay in the body chamber, the shell did not shatter except for the body chamber. The phragmocone typically remained intact except for the puncture marks created by the teeth. In only three out of the 20 times did the phragmocone break and this was always between the first and second septum or across the first or second septum. Furthermore, breaking of the phragmocone only occurred when a tooth row crossed the phragmocone at the first or second septum. So whether the shell was dry or not appeared to have a significant impact on whether it shattered. One of the 20 wet shells was crushed without any clay in the body cavity. The resulting shattering of the body chamber and puncturing of the phragmocone was similar to the results for the 19 wet shells that had clay in them. This similarity indicates that having the body chamber filled did not play a large role in whether the shell shattered or not. However, since only one wet shell without clay was crushed, this conclusion is tentative. 23

An overview of the conditions of the skull in each of the crushing trials of the wet shells is shown in Table 3. The structure of this table was explained in the Methods section.

In all of the trials, the body chamber was broken, although in a few cases, only one side was broken while the other was still intact. In all cases where only one half of the body chamber was broken, it was the top of the shell that was broken. The reason the top of the body chamber would break is because when the shell was placed between the jaws of the skull, teeth were in contact with the top and bottom of the body chamber and the phragmocone typically was dropped toward the lower tooth row. In some cases, the phragmocone actually rested on the lower tooth row. As the shell was being crushed, the bottom of the shell would have more teeth in contact with it (teeth in the dentary would be in contact with both the body chamber and phragmocone while teeth in the upper jaw would only be in contact with the body chamber). This arrangement would create a “bed of nails” effect: more teeth in contact with one side would distribute the force more evenly and reduce the pressure. Thus, it would be expected that the top of the body chamber would be most likely to break.

In three (15%) of the cases, it was noted that one or more holes were present on one half of the phragmocone but there were no holes on the other side of the phragmocone. Instead, there were only indentations. This pattern occurred in specimens 9, 12, and 19. Pictures of specimens 12 and 19 partway through crushing are shown in Figures 18 and 19, respectively. In all three cases, puncture marks on only one side of the phragmocone occurred partway during the crushing of the shell; when the shell was completely crushed, holes existed on both the top and the bottom of the phragmocone. In two of these cases (specimens 9 and 19), the phragmocone was resting on the lower tooth row before crushing began. As might be expected with the “bed of nails” effect, partway through crushing, there were puncture marks on the top of the phragmocone but none on the bottom in specimen 19.

However, specimen 9 showed the opposite effect: partway through crushing, there were puncture marks on the bottom of the phragmocone and not on the top. The reason the bottom of the 24

phragmocone punctured before the top of the phragmocone in specimen 9 is not understood. In specimen 12, the phragmocone was centered over a place that had a missing tooth. Partway through crushing, specimen 12 had puncture marks on the bottom of its phragmocone and none on the top, which is likely a result of there being fewer teeth impacting the bottom of the phragmocone, again producing a “bed of nails” effect.

The results for the force measurements are shown in Table 4. The forces ranged from 1503 N to

4048 N and do not appear to vary with shell orientation. These forces are comparable to the force bites measured in alligators, as these bite forces are measured under a specific location in the alligator’s jaws.

As described by Erickson et al. (2004), the measuring of the bite force of an alligator simply measures the force applied by the alligator’s jaws to bite force transducers centered under the 11th maxillary tooth. In the current study, the force of the press was applied over the location of the Nautilus shell in the jaws, which was centered under either the 8th or 9th maxillary tooth.

Along with bite forces, the stress applied by the teeth on the shell was calculated. Several assumptions had to be made to perform this calculation: 1) the area of contact between the teeth and the shell were equal on both sides of the shell, 2) the body chamber had broken so that the teeth were only in contact with the clay, 3) the clay provided minimal resistance, 4) three teeth from the upper jaw and the dentary had punctured the phragmocone, one to a depth of 8 mm and the other two to a depth of 5 mm. Some of these assumptions could have been controlled or measured, however, these calculations were done in hindsight, after the crushing tests had already been performed. The number of teeth and their depth of penetration is an estimate based on the results of the crushing of the wet shells.

To calculate the area of contact, the perimeter around the three central teeth in the replica in the upper jaw and the dentary (teeth 9-11 in the upper jaw and teeth 7-9 in the dentary) were measured at a distance of 5 mm from the tip and a distance of 8 mm from the tip. The average 25

perimeter at 5 mm was 9.7 mm and the average perimeter at 8 mm was 13.4 mm. With one tooth at a depth of 8 mm and two at a depth of 5 mm, the sum of the perimeters would be 32.8 mm. The average thickness of a Nautilus shell is 1.0 mm, so the total area along the edge of three puncture marks would be 32.8 mm2. The bite forces measured would then be divided by this area. The maximum range of stress applied by the replica jaws to a Nautilus shell would range from 45.8 MPa to 123 MPa. Note that these calculations give the stress applied by one side of the jaws. These stresses are likely higher than they actually were, as more precise calculations would take into account the part of the jaws that are in contact with the clay.

Discussion:

The findings from the tooth measurements show that the position of adjacent teeth in mosasaurs is variable. In some cases, two adjacent teeth can have tips that are adjacent or nearly adjacent to each other, as seen in YPM 85586 and YPM 2062 (Figures 12 and 13). Should the mosasaur bite an ammonite, such a condition would likely result in double puncture marks similar to those discussed by Kase et al. (1998) and Tsujita and Westermann (2001). The old and new teeth occupying the same socket, as seen in YPM 2062 (Figure 15) and AMNH 134 (Figure 16) would produce a different kind of puncture mark where one hole is noticeably smaller than the other, and the two holes would likely be connected, as the new and old teeth are in contact with each other. These double puncture marks would look like the dumbbell shaped double puncture marks described by Tsujita and

Westermann (2001). The fact that mosasaurs have teeth whose tips are close to each other contradicts the notion that mosasaurs are incapable of producing double puncture marks, as suggested by Kase et al. (1998).

Both of these conditions (adjacent tooth tips and old and new tooth in the same socket) are rare: there were only two instance of each out of 117 complete tooth pairs (the 115 tooth pairs plus the 26

two old and new teeth in the same socket). Based on these numbers, both occur about 1.71% of the time, making them very rare occurrences. It is not known how this percentage compares to the observed occurrence of double puncture marks in ammonite shells, although Tsujita and Westermann

(2001) note that most puncture marks are single holes, indicating that double puncture marks are rare.

Triple puncture marks have also been noted in ammonite shells. These are said to be very rare

(Tsujita and Westermann 2001). Interestingly, YPM 2062 displays an arrangement that may have produced triple puncture marks. YPM 2062 (Figure 15) has a pair of teeth whose tips are unusually close to each other and a new tooth is occupying the socket of one of these teeth. YPM 2062 itself may not have been able to produce triple puncture marks, as the new tooth lies under the curve of the old tooth.

However, this specimen does show that triple tooth marks may be possible if all three teeth are separated enough that they would create their own holes.

The crushing of the Nautilus shells showed that it was possible to produce puncture marks on one side of the shell that did not have any corresponding holes on the other side of the shell. Puncture marks on only one flank of the phragmocone were observed when the shell was partially crushed three times out of the 20 specimens that were crushed, giving an occurrence of 15%. None of the completely crushed shells had puncture marks on only one flank of the phragmocone. This percentage is greater than the occurrence noted in Kase et al. (1998). Out of 72 specimens they observed, four had holes on only one flank, giving an occurrence of 5.6%. Much of the reason the occurrence of puncture marks on only one flank was so high in this study was because conditions needed to produce these types of puncture marks were intentionally repeated. Still, the comparison of these two occurrence rates does show that it is possible to match the occurrence of puncture marks found on only one side of an ammonite’s shell found in the fossil record. Kase et al. (1998) again cite these occurrences as evidence that mosasaurs were not producing the puncture marks. However, the present study invalidates this view and indicates instead that mosasaurs were capable of producing these types of puncture marks. 27

The Nautilus shells described here differ from the ammonite shells described by Kase et al. (1998) because they describe ammonites with puncture marks on one flank but none on the other. The

Nautilus shells produced in this study did not actually have this condition, as the body chamber was still crushed or punctured on both sides, even though the phragmocone had puncture marks on one side only. However, as was noted earlier, the body chamber of Nautilus is much wider than the body chamber of Placenticeras, so the teeth would have to break through the body chamber in Nautilus before both the upper and lower tooth rows come in contact with the phragmocone, while in

Placenticeras, the teeth from both the upper and lower jaws could be in contact with the phragmocone and body chamber from the beginning of the bite motion. At the least, though, producing puncture marks on only one side of the phragmocone indicates that it is possible to arrange the teeth so that one side would puncture before the other. The results of the current study support the suggestion by Tsujita and Westermann (2001) that a “bed of nails” effect could be responsible for puncture marks on only one flank of an ammonite’s shell. Tsujita and Westermann’s other suggestion, that the mosasaur’s teeth may impact on the umbilical shoulder and fail to penetrate it, does not seem to have been born out. In trials 3, 11, 12, 19, and 20, there is a puncture mark evident on the umbilical shoulder. In fact, in trials

12 and 19, the side on which the umbilical shoulder puncture occurs is the side on which the puncture marks first appeared.

It is interesting that puncture marks restricted to one side of the phragmocone were only observed when the shell was partially crushed but never when a shell was completely crushed. Since these puncture marks only occurred on incompletely crushed shells, such puncture marks on ammonite shells may have been created when a mosasaur bit down relatively lightly. A weak bite may have been the result of a mosasaur manipulating an ammonite around in its mouth, rather than an attack bite that was designed to incapacitate the ammonite. 28

There is another helpful comparison between the study by Kase et al. (1998) and this study.

Kase et al. (1998) also used a steel mosasaur skull to crush Nautilus shells. They noted that deep bites broke the shells into several fragments and that shallower bites, while not shattering the shell, produced angular holes and cracks. In contrast, the twenty wet specimens crushed in this study did not shatter and the cracks and holes were not as angular as those of Kase et al. (1998). The difference may be that the Nautilus shells in this study were wet when they were crushed. As was noted previously, two dry

Nautilus shells were crushed early on and they shattered in a manner similar to that described by Kase et al. (1998). Kase et al. (1998) do not note whether or not the shells they used were wet or dry, only that they were “fresh”, but it is suggested that the observed differences may have been in part the result of crushing dry versus wet shells. As an ammonite’s shell in life would certainly have been wet, it is suggested that the wet shells in this study behaved in a manner closer to the way an ammonite shell would if a mosasaur bit it.

A further comparison to the puncture marks produced by Kase et al. (1998) is in the beveling of the holes. Kase et al. (1998) noted that their experimental holes had sides that were inclined inwardly

(like and inverted V) in cross-section, and that this differed from the puncture marks in ammonites, where the sides of the holes were beveled (V-shaped in cross section). Beveled holes were repeatedly observed in the current study (an example is shown in Figure 20), showing how another feature of puncture marks in ammonite shells can be accounted for by mosasaur predation. In comparison, the hole made in one of the dry shells is shown in Figure 21.

The range of bite forces measured in the current study (1503 N – 4048 N) is lower than the range of bite forces Kase et al. (1998) used with their model jaws (6346 N – 10,974 N). In comparison with the measured bite forces of alligators, the bite forces measured in this study fall toward the lower end of the range of bite forces for alligators (217 N – 13,172 N) (Erickson et al. 2004). Since the bite forces measured are much lower than the highest measured bite force for a living animal, it would be 29

reasonable to assume that a mosasaur, such as Prognathodon, would be capable of producing the necessary force to puncture an ammonite’s shell.

The bite pressure can also be compared to previous research. Grubich et al. (2008) reported that a barracuda could theoretically produce a bite pressure of 61 MPa at the tip of its large canine, which is within the range calculated in this study for mosasaurs (45.8 - 123 MPa). As the bite pressure need to puncture Nautilus shells is similar to that found in living animals, it is concluded that mosasaurs would have physically been capable of producing puncture marks in ammonites.

Conclusion:

This study has shown that the orientation of mosasaurs’ teeth can be variable and that in rare cases, the tips of adjacent teeth can be very close to one another. It is likely that such teeth could have produced double puncture marks. Instances in which a new tooth occupied the same socket as an older tooth were also observed and it is likely that these too could have produced double puncture marks. It was therefore concluded that double puncture marks in ammonite shells could have been produced by mosasaurs. Puncture marks on one side of the phragmocone but not on the other could be produced in

Nautilus shells with a partial bite from a mosasaur skull model in this study. These experimental results indicate that mosasaurs would also have been capable of producing these types of puncture marks found in ammonite shells. As mosasaurs appear to have been capable of producing these unique types of puncture marks, the claim that mosasaurs preyed on ammonites and made the puncture marks in their shells has been further supported.

Works Cited:

Bukowski, Frank and Paul Bond (1989) “A predator attacks Sphenodiscus” The Mosasaur 4: 69-74.

Caldwell, M. W. (2007) “Ontogeny, anatomy and attachment of the dentition in mosasaurs

(Mosasauridae: Squamata)” Zoological Journal of the Linnean Society 149: 687-700.

Daniel, Thomas L., Brian S. Helmuth, W. Bruce Saunders, and Peter D. Ward (1997) “Septal complexity in

ammonoid cephalopods increased mechanical risk and limited depth” Paleobiology 23(4): 470-

481.

Erickson, Gregory M., A. Kristopher Lappin, Trevor Parker, and Kent A. Vliet (2004) “Comparison of bite-

force performance between long-term captive and wild American alligators (Alligator

mississippiensis)” Journal of Zoology 262: 21-28.

Everhart, Michael J. (2005) “Enter the Mosasaurs” Chapter 9 in Oceans of Kansas: A Natural History of

the Western Interior Sea, Indiana University Press, Bloomington and Indianapolis.

Grubich, Justin R., Aaron N. Rice, Mark W. Westneat (2008) “Functional morphology of bite mechanics in

the great barracuda (Sphyraena barracuda)” Zoology 111: 16-29.

Hammer, Øyvind, D.A.T. Harper and P.D. Ryan (2008) PAST, PAlaeontological STatistics, ver. 1.87,

http://folk.uio.no/ohammer/past/download.html

Hassan, Marwan A., Gerd E. G. Westermann, Roger A. Hewitt, and Mohamed A. Dokainish (2002)

“Finite-element analysis of simulated ammonoid septa (extinct Cephalopoda): septal and sutural

complexities do not reduce strength” Paleobiology 28(1): 113-126.

Hewitt, R. A. and G. E. G. Westermann (1990) “Mosasaur tooth marks on the ammonite Placenticeras

from the Upper Cretaceous of Alberta, Canada” Canadian Journal of Earth Sciences 27: 469-472.

Kase, Tomoki, Paul A. Johnston, Adolf Seilacher, and Japeth B. Boyce (1998) “Alleged mosasaur bite

marks on Late Cretaceous ammonites are limpet (patellogastropod) home scars” Geology

26(10): 947-950. 31

Kauffman, Erle G. (1990) “Mosasaur predation on ammonites during the Cretaceous—An evolutionary

history” in Boucot, A. J. (Ed.) Evolutionary Paleobiology of Behavior and Coevolution Elsevier,

Amsterdam, 184-189.

Kauffman, Erle G. and Robert V. Kesling (1960) “An Upper Cretaceous ammonite bitten by a mosasaur”

Contributions from the Museum of Paleontology, University of Michigan 15(9): 193-248.

Kues, Barry S. and Spencer G. Lucas (1985) “Mosasaur remains from the Lewis Shale (Upper Cretaceous),

Southwestern Colorado” Journal of Paleontology 59(6): 1395-1400.

Massare, Judy (2006) “New specimen of Prognathodon (Reptilia: Mosasauridae) from the Bearpaw

Formation of Alberta” Journal of Vertebrate Paleontology 26(3 Suppl.): 96.

Russell, Dale A. (1967) “Systematics and Morphology of American Mosasaurs” Peabody Museum of

Natural History Bulletin 23, 241 pg.

Schulp, A. S. (2004) “Feeding the Mechanical Mosasaur: what did Carinodens eat?” Netherlands Journal

of Geosciences, 84(3): 345-357.

Tsujita, Cameron J. and Gerd E. G. Westermann (1998) “Ammonoid habitats and habits in the Western

Interior Seaway: a case study from the Upper Cretaceous Bearpaw Formation of southern

Alberta, Canada” Palaeogeography, Palaeoclimatology, Palaeoecology 144: 135-160.

Tsujita, Cameron J. and Gerd E. G. Westermann (2001) “Were limpets or mosasaurs responsible for the

perforations in the ammonite Placenticeras?” Palaeogeography, Palaeoclimatology,

Palaeoecology 169: 245-270. 32

Figure 1: A Placenticeras specimen with puncture marks. Note that the puncture marks (with the exception of the one indicated by the arrow) fall along two lines, which are interpreted as corresponding to the tooth rows of a mosasaur’s jaws. The other may be the result of a second bite that overlaps one of the other rows. Scale bar is 5 cm. Modified from Kaufmann (1990). 33

Figure 2: Reconstruction of Tylosaurus, a common mosasaur. Tylosaurus averaged around 9 m long.

Modified from Everhart (2005).

Figure 3: Example of a double puncture mark in an ammonite shell. The individual holes are pointed out by the arrows. In this case, the holes are actually connected. In some double puncture marks, the two holes are not connected. Scale bar is 10 mm. Modified from Tsujita and Westermann (2001).

Figure 4: Coordinate system for tooth morphometrics. The upper and lower jaws each have their own coordinate system. The origin is the base of the posterior-most tooth and the x-axis runs through the base of the anterior-most tooth. The teeth are numbered from the origin (the posterior-most tooth) forward. The position of the base and tip of each tooth is noted. Prognathodon overtoni skull modified from Russell (1967). ang: Angular, art: Articular, cor: Coronoid, den: Dentary, fro: Frontal, jug: Jugal, max: Maxilla, par:

Parietal, prf: Prefrontal, pre: Premaxillae, pof: Postorbitofrontal, qua: Quadrate, spl: Splenial, squ:

Squamosal, sur: Surangular.

Figure 5: Streptostyly in a mosasaur’s skull. Top shows the quadrate rotated forward, bottom shows the quadrate rotated backwards (modified from Russell 1967).

Figure 6: Mandibular movement in a mosasaur’s jaw. Top shows the dentary and splenial depressed, bottom shows the dentary and splenial elevated (modified from Russell 1967).

Figure 7: Pattern used for the construction of the skull replica. A. is the upper jaw, B. is the dentary, C. is the mandible, and D. is the quadrate. Scale bar is 5 cm.

Figure 8: The complete skull replica. The dentary with the missing teeth is not shown in this illustration.

The ruler is 15 cm long.

Table 1: Experimental plan for the crushing of the wet Nautilus shells. It should be noted that this plan was not fixed before the experiment began. Rather, it was altered during the course of the experiment to focus on different conditions that showed results with puncture marks on only one flank of the shell.

Conditions of Skull Dentary with all Teeth Dentary with Missing Teeth Total Trials

Skull at rest (no streptostyly Trials 1, 2, 3, 8, 9, 10, Trials 11, 12, 13 11 movement, no mandibular flexing) 19, and 20

Lower jaw retracted, no Trials 4 and 5 Trials 14 and 15 4 mandibular flexing

Lower jaw protracted, no Trials 6 and 7 2 mandibular flexing

Dentary elevated, no streptostyly Trials 16, 17, and 18 3 movement

Total 15 5 20

Figure 9: Plot of complete and chipped tooth pairs for the maxilla. Both axes are unitless distances relative to the distance between the bases of the teeth. The base of the posterior-most tooth is the origin, the base of the anterior-most tooth is at (1,0). The circled purple squares show the tips of YPM

2062. The circled red crosses show the tips of KUM 85586. Black dots: Clidastes, red crosses:

Platecarpus, blue squares: Tylosaurus, purple squares: unidentified genera, green crosses: premaxilla teeth of Platecarpus.

Figure 10: Plot of complete and chipped tooth pairs for the dentary. Both axes are unitless distances relative to the distance between the bases of the teeth. The base of the posterior-most tooth is the origin, the base of the anterior-most tooth is at (1,0). Black dots: Clidastes, red crosses: Platecarpus, blue squares: Tylosaurus, purple squares: unidentified genera.

Table 2: Statistics for the distribution of the tooth tips in tooth pairs in the dentary. These are univariate

statistics; the x- and y-coordinates are treated separately.

Species Axis Number Minimum Maximum Mean Standard

Deviation

Clidastes X 12 -0.139 0.062 -0.050 0.058

Clidastes Y 12 0.793 1.312 1.105 0.183

Platecarpus X 70 -0.424 0.562 -0.081 0.177

Platecarpus Y 70 0.772 2.062 1.303 0.261

Tylosaurus X 42 -0.394 -0.021 -0.200 0.101

Tylosaurus Y 42 0.694 1.362 1.009 0.154

Unknown X 4 -0.057 0.300 0.055 0.167

Unknown Y 4 0.550 0.800 0.684 0.103

Total X 128 -0.424 0.562 -0.113 0.160

Total Y 128 0.550 2.062 1.169 0.272

Table 3: Statistics for the distribution of the tooth tips in tooth pairs in the maxilla. These are univariate

statistics, the x- and y-coordinates are treated separately. Teeth from the premaxilla of a

Platecarpus were included in the total, but as there were only two teeth, it was not shown

separately.

Species Axis Number Minimum Maximum Mean Standard

Deviation

Clidastes X 20 -0.533 -0.036 -0.197 0.122

Clidastes Y 20 -1.600 -0.250 -0.930 0.306

Platecarpus X 54 -0.744 0.722 -0.209 0.241

Platecarpus Y 54 -1.909 -0.378 -1.363 0.290

Tylosaurus X 16 -0.382 0.047 -0.132 0.137

Tylosaurus Y 16 -1.380 -0.861 -1.132 0.140

Unknown X 10 -0.760 0 -0.297 0.231

Unknown Y 10 -1.831 -0.659 1.329 0.457

Total X 102 -0.760 0.722 -0.196 0.213

Total Y 102 -2.19 -0.250 -1.250 0.352

Figure 11: Plot of tooth tips in the dentary with convex hulls. The base for all of these teeth is at (0,0).

Black dots: Clidastes, red crosses: Platecarpus, blue squares: Tylosaurus, purple squares:

unknown genera. 46

Figure 12: Plot of tooth tips in the maxilla with convex hulls. The base for all of these teeth is at (0,0).

Black dots: Clidastes, red crosses: Platecarpus, blue squares: Tylosaurus, purple squares:

unknown genera. 47

Figure 13: Distance between the tips of the teeth in the tooth pairs. The distances are based on

Bookstein coordinates. The x-axis shows the individual tooth pairs, which are numbered from 1 to 115.

The purple lines show the ± 1.96 standard deviation lines. Notable outliers at the lower end of the graph are indicated with arrows. These outliers are shown in Figures 14 and 15. 48

Figure 14: Tooth pair in a Platecarpus sp. whose teeth tips are very close to each other. Tooth pair indicated by red arrow. KUM 85586.

Figure 15: Tooth pair in an unknown mosasaur whose tips are close to each other. The tooth pair in question are the two large teeth on the right (indicated by TP). In addition, this specimen also shows a new tooth emerging in the socket of an older tooth (indicated by NT). YPM 2062.

Figure 16: New tooth occupying the same socket as an old tooth. The new tooth is indicated by an arrow. Tylosaurus nepaeolicus. AMNH 134.

Figure 17: Crushed remains of dry Nautilus shells. These are just the remains of the phragmocone, the

pieces from the body chamber were discarded. Note the angular breakage pattern. Scale bar is

2 cm.

Figure 18: Puncture marks on specimen 12 partway through crushing. A. shows the top of the specimen,

B. shows the bottom. Note that there is a hole in the phragmocone on the bottom but none on

the phragmocone on the top. Scale bar is 2 cm.

Figure 19: Puncture marks on specimen 19 partway through crushing. A. shows the top of the specimen,

B. shows the bottom. Note that there is a hole in the phragmocone on the top but none on the

phragmocone on the bottom. Scale bar is 2 cm.

Table 4: Results of bite force measurements. All of the shells were centered between the 8th and 9th

teeth in the maxilla, except for the shell in trial 1, which was centered under the 10th tooth in

the maxilla.

Trial Original Orientation Maximum Force

1 Body chamber on the left, aperture pointing forward and to the right. 3808 N

2 Body chamber on the right, aperture pointing to the left 3603 N

3 Body chamber on the left, aperture pointing forward and to the right. 2095 N

4 Body chamber on the right, aperture pointing to the left. 1503 N

5 Body chamber on the left, aperture pointing forward and to the right. 4048 N

6 Body chamber on the right, aperture pointing forward and to the left. 3536 N

Figure 20: Close up of a puncture mark made in a wet Nautilus shell. Note the beveled edge of the sides

of the hole.

Figure 21: Close up of a puncture mark made in a dry Nautilus shell. Note the lack of a beveled edge and

that several fractures extend from the hole. Compare to Figure 20. 56

Appendix A: Tables of Tooth Measurements and Transformation to Bookstein Coordinates

Table A1 shows the coordinates of the base (socket) and tip of every tooth from all of the specimens measured in this study. In all, 121 specimens were measured, consisting of 202 jaws and jaw fragments.

Table A2 shows the tooth pairs that were subsequentially transformed to Bookstein coordinates. These tooth pairs consist of all of the adjacent complete and chipped teeth in Table A1. It should be noted that some teeth appear twice in this table: if a tooth is adjacent to two complete or chipped teeth, then that tooth will appear with each of the other teeth in two distinct pairs.

To transform the measured coordinates to Bookstein coordinates, all of the coordinates of a single tooth pair had to be arranged in a single row (this being the format required by the software package PAST for the transformation). Tables A3 and A4 show the coordinates in this arrangement and their corresponding Bookstein coordinates. Four tooth pairs from Table A2 were altered when they were arranged in Tables A3 and A4. These four tooth pairs all included a new tooth that occupied the same socket as an older tooth. When these new teeth were paired with an old tooth and transformed to Bookstein coordinates, there proportions were radically different from the rest of the pairs. These four tooth pairs were the result of two new teeth, both new teeth appearing in two different pairs, once with the tooth anterior to it and once with the tooth posterior to it. Because they were out of proportion with the other pairs, these four pairs were dropped. Instead, two new tooth pairs were formed: the teeth on either side of a new tooth were put together to form one pair. The end result was that four original tooth pairs were replaced with two new tooth pairs. The Bookstein coordinates from

Tables A3 and A4 were plotted in PAST and are shown as Figures 11 and 12 in the main text.

Table A5 shows the calculations performed on the Bookstein coordinates in preparation for doing statistics. First, the x-coordinate of the tip of the second tooth in a tooth pair was subtracted by 57

one so that its displacement along the x-axis would be relative to zero. Secondly, the distance between the tips of the teeth in a pair was calculated. 56

Table A1: Tooth measurements. The table is set up so that the specimen number and species are shown in the columns on the left. On the right, each box corresponds to a specific part of the jaw or jaw fragment. The top row in these boxes on the right states what the bone is (L. and

R. denote left and right, respectively) followed by the number designating each tooth in the jaw or jaw fragment. The teeth are numbered, starting with the posterior-most tooth in the jaw or jaw fragment. Following the tooth number, the condition of the tooth is noted. The designations for the condition of the teeth are as follows: blank: tooth is whole, t. broke: the tooth is broken; t. bent: the tooth is bent; t. chip: the tip of the tooth is chipped, distinguished from t. broke because in t. chip, only one or two millimeters of the tip is missing; absent: the tooth is missing; s. broke: the tooth is missing and the socket is broken; t. new: tooth is new and is significantly smaller than its neighbors; t. buried: part of the tooth is buried in matrix; w. buried: the whole tooth is buried in matrix; abs bur: the tooth and socket are both buried in matrix; t. crack: the tooth is cracked but appears to retain its original shape and position; t. bent: the tooth is noticeably bent; ?: by itself or with one of the other designations, a question marks means the condition of the tooth is uncertain (this is due to confusion in my notes). Below the number and noted condition of each tooth are the coordinates for the tooth tip and socket. The coordinates are simply the x-coordinate followed by the y-coordinate in millimeters. N/A is given if the position of either the tooth tip or the socket could not be determined.

Specimen Species Jaw Bone Teeth KUM 4862 Platecarpus coryphaeus L. Maxilla 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip -1 -6 24 -2 49 -7 75 -9 Socket 0 0 26 2 52 4 75 4 (cont.) 5 t. broke 6 t. broke 7 t. bent 8 t. broke Tooth Tip 101 -7 119 -12 144 -9 183 -14 Socket 103 5 129 3 161 0 184 0

Specimen Species Jaw Bone Teeth KUM 85502 Platecarpus sp. L. Maxilla 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 0 -3 21 -9 43 -12 64 -9 Socket 0 0 20 0 45 1 64 2 (cont.) 5 t. broke 6 t. broke 7 t. broke 8 t. broke Tooth Tip 85 -16 110 -18 130 -10 150 -11 Socket 85 2 110 2 132 1 151 0 R. Maxilla 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 0 -9 19 -19 38 -25 66 -24 Socket 0 0 22 0 42 0 67 -5 (cont.) 5 t. new 6 t. broke 7 t. broke 8 t. new Tooth Tip 78 -26 110 -25 132 -19 153 -18 Socket 85 -3 111 -1 132 0 157 0 (cont.) 9 t. broke 10 t. broke 11 t. broke Tooth Tip 174 -18 195 -16 213 -8 Socket 174 0 194 0 214 0 R. Dentary 1 t. broke 2 t. broke 3 absent 4 Tooth Tip 0 4 22 14 N/A 66 21 Socket 0 0 22 0 43 2 65 2 (cont.) 5 t. broke 6 t. new 7 t. broke 8 t. broke Tooth Tip 88 6 103 6 131 10 153 13 Socket 88 3 108 3 132 2 154 0 KUM 14271 Clidastes sp. L. Maxilla 1 t. broke 2 t. broke 3 absent 4 t. chip Tooth Tip 0 -10 15 -12 N/A 53 -19 Socket 0 0 18 1 33 2 56 0 (cont.) 5 6 7 8 t. broke Tooth Tip 0 -20 Socket 0 0 58

Specimen Species Jaw Bone Teeth KUM 14271 Clidastes sp. (cont.) 9 absent 10 t. broke 11 t. chip 12 t. broke Tooth Tip N/A 36 -12 53 -20 72 -4 Socket 18 2 37 2 55 2 72 2 (cont.) 13 t. broke 14 t. broke 15 absent 16 t. chip Tooth Tip 89 -3 104 -8 N/A 130 -18 Socket 89 1 103 1 117 0 132 0 (cont.) 17 t. broke Tooth Tip 146 -10 Socket 144 0 KSM 1114 Platecarpus sp. R. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 2 9 21 7 42 4 63 4 Socket 0 0 20 -3 42 -6 63 -7 (cont.) 5 t. broke 6 t. broke 7 t. broke 8 t. broke Tooth Tip 85 3 104 7 124 8 143 10 Socket 85 -7 104 -6 124 -5 145 -4 (cont.) 9 t. broke 10 t. broke 11 t. broke 12 t. broke Tooth Tip 163 10 179 13 196 6 214 12 Socket 165 -2 180 -1 196 0 211 0 KUM 1135 Platecarpus sp. L. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. chip Tooth Tip 1 8 19 7 47 6 70 18 Socket 0 0 19 -3 47 -4 71 -4 (cont.) 5 t. broke 6 t. broke 7 t. broke 8 t. broke Tooth Tip 95 15 118 11 140 16 162 8 Socket 94 -2 117 1 138 1 158 0 KUM 1140 Platecarpus sp. R. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 1 9 24 10 44 11 70 8 Socket 0 0 23 -1 44 -2 70 -3

Specimen Species Jaw Bone Teeth KUM 1140 Platecarpus sp. (cont.) 5 absent 6 t. broke 7 absent 8 t. broke Tooth Tip N/A 117 9 N/A 158 12 Socket 90 -5 115 -1 134 -2 157 1 (cont.) 9 t. broke Tooth Tip 179 11 Socket 176 0 KUM 5016 Platecarpus sp. R. Maxilla 1 t. broke 2 t. broke 3 absent 4 t. broke Tooth Tip 0 -4 28 -14 N/A 77 -14 Socket 0 0 26 0 52 1 76 1 (cont.) 5 t. broke 6 t. broke 7 t. broke 8 t. broke Tooth Tip 102 -3 125 -14 147 -17 170 -13 Socket 102 1 125 1 147 0 169 0 (cont.) 9 t. broke Tooth Tip 191 -12 Socket 191 0 KUM 1046 Platecarpus sp. L. Maxilla 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 0 -10 21 -8 39 -8 60 -9 Socket 0 0 21 1 40 2 60 2 (cont.) 5 t. broke 6 t. broke 7 t. broke 8 t. broke Tooth Tip 80 -10 98 -9 118 -9 136 -9 Socket 81 2 100 2 119 2 136 1 (cont.) 9 t. broke Tooth Tip 152 -10 Socket 152 0 R. Maxilla 1 t. broke 2 t. broke 3 t. broke 4 absent Tooth Tip 0 -10 13 -10 32 -9 N/A Socket 0 0 12 1 32 0 52 1

Specimen Species Jaw Bone Teeth KUM 1046 Platecarpus sp. (cont.) 5 t. broke Tooth Tip 71 -11 Socket 71 0 L. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 0 8 21 11 41 9 61 12 Socket 0 0 22 -1 42 -1 61 0 L. Dentary 5 absent 6 t. broke 7 t. broke 8 absent Tooth Tip N/A 98 12 115 9 N/A Socket 80 0 98 0 113 1 122 0 R. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip -1 10 17 12 34 9 54 12 Socket 0 0 19 0 35 0 56 0 R. Dentary 5 t. broke Tooth Tip 70 8 Socket 70 0 KUM 5035 Platecarpus sp. L. Maxilla 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 0 -14 25 -28 51 -15 69 -30 Socket 0 0 27 0 51 -2 71 0 (cont.) 5 t. broke 6 t. broke 7 t. broke 8 t. broke Tooth Tip 94 -19 117 -22 138 -25 162 -15 Socket 96 0 118 0 140 0 162 0 (cont.) 9 t. broke Tooth Tip 182 -10 Socket 182 0 L. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 2 12 20 5 46 15 66 11 Socket 0 0 22 -4 45 0 64 0

Specimen Species Jaw Bone Teeth KUM 5035 Platecarpus sp. (cont.) 5 t. broke 6 t. broke Tooth Tip 88 16 104 13 Socket 83 0 99 0 KUM 1051 Platecarpus sp. R. Maxilla 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 1 -9 24 -8 44 -15 71 -13 Socket 0 0 24 1 45 1 70 0 R. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 0 12 22 14 43 18 63 10 Socket 0 0 21 2 42 2 60 0 L. Dentary 1 t. broke 2 t. broke 3 t. broke Tooth Tip 0 12 23 13 39 6 Socket 0 0 20 0 35 0 KUM 1052 Platecarpus sp. R. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 0 8 22 9 41 10 60 9 Socket 0 0 22 0 41 0 60 0 (cont.) 5 t. broke Tooth Tip 78 10 Socket 76 0 L. Dentary 1 t. broke 2 t. broke 3 t. broke Tooth Tip 2 14 24 16 45 13 Socket 0 0 23 0 42 0 KUM 1054 Platecarpus sp. L. Dentary 1 t. broke 2 t. broke 3 absent 4 t. broke Tooth Tip -5 9 13 9 N/A 47 10 Socket 0 0 15 2 32 1 48 2 (cont.) 5 t. broke Tooth Tip 64 10 Socket 65 0

Specimen Species Jaw Bone Teeth KUM 14264 Platecarpus sp. R. Maxilla 1 t. buried 2 t. chip 3 absent 4 t. buried Tooth Tip 2 -31 24 -31 N/A 64 -23 Socket 0 0 21 0 45 1 62 0 KUM 69451 Platecarpus sp. R. Dentary 1 t. broke 2 t. broke 3 abs bur 4 t. broke Tooth Tip 5 46 38 37 N/A 90 24 Socket 0 0 37 0 N/A 86 0 (cont.) 5 t. broke Tooth Tip 109 12 Socket 108 0 KUM 85586 Platecarpus sp. R. Maxilla 1 t. chip 2 3 4 Tooth Tip 2 -9 3 -9 20 -14 34 -15 Socket 0 0 9 0 20 4 39 4 (cont.) 5 absent 6 t. buried 7 t. buried 8 t. buried Tooth Tip N/A 86 -19 109 -21 130 -22 Socket 62 8 87 8 110 9 134 10 (cont.) 9 t. broke 10 absent 11 12 abs bur Tooth Tip 160 -11 N/A 200 -30 N/A Socket 158 8 182 6 205 3 N/A (cont.) 13 t. broke Tooth Tip 252 -26 Socket 247 0 KUM 85587 Platecarpus sp. L. Maxilla 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 0 -10 23 -19 47 -12 70 -11 Socket 0 0 23 0 47 0 69 0 R. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 0 11 23 12 40 9 67 7 Socket 0 0 23 0 46 0 67 0

Specimen Species Jaw Bone Teeth KUM 85587 Platecarpus sp. (cont.) 5 t. broke 6 absent 7 t. broke Tooth Tip 89 12 N/A 127 12 Socket 89 1 107 2 123 0 KUM 1009 Tylosaurus indet. R. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 1 19 34 24 77 18 111 16 Socket 0 0 34 0 77 0 108 0 R. Dentary 5 t. broke Tooth Tip 152 12 Socket 150 0 with KUM 1009 Platecarpus sp. R. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 0 13 22 14 45 17 66 14 Socket 0 0 21 0 46 2 67 3 (cont.) 5 t. broke 6 absent Tooth Tip 86 14 N/A Socket 85 3 103 0 L. Dentary 1 t. broke 2 t. broke 3 absent 4 t. broke Tooth Tip 1 9 21 17 N/A 66 9 Socket 0 0 20 0 40 -4 63 0 KUM 1048 Tylosaurus sp. R. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 0 12 18 8 38 14 59 13 Socket 0 0 19 0 40 0 59 0 L. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 0 7 21 9 40 9 62 9 Socket 0 0 21 0 40 0 62 0 R. Maxilla 1 t. broke 2 absent 3 t. broke 4 t. broke Tooth Tip 2 -14 N/A 42 -9 60 -9 Socket 0 0 121 2 41 2 59 1

Specimen Species Jaw Bone Teeth KUM 1048 Tylosaurus sp. (cont.) 5 t. broke 6 t. broke 7 t. broke Tooth Tip 91 -12 102 -5 124 -13 Socket 91 1 102 0 124 0 KUM 1168 Tylosaurus sp. R. Maxilla 1 t. broke 2 absent 3 t. broke 4 t. broke Tooth Tip 0 -18 N/A 72 -17 112 -18 Socket 0 0 34 1 71 -1 111 -1 (cont.) 5 absent 6 t. broke 7 t. broke Tooth Tip N/A 186 -19 222 -17 Socket 146 1 183 0 219 0 L. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 3 9 34 10 68 12 100 19 Socket 0 0 33 -1 68 -3 102 -3 (cont.) 5 t. broke Tooth Tip 137 14 Socket 137 0 KUM 1058 Mosasauridae R. Dentary 1 t. chip 2 abs bur 3 t. chip 4 abs bur Tooth Tip 0 22 N/A 47 23 N/A Socket 0 0 N/A 42 0 N/A (cont.) 5 t. chip 6 t. buried Tooth Tip 88 25 109 23 Socket 87 0 106 0 KUM 1118 Mosasauridae R. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 0 14 27 14 50 14 70 14 Socket 0 0 26 0 50 0 72 0 (cont.) 5 t. broke 6 t. broke 7 t. broke Tooth Tip 93 16 113 15 130 11 Socket 94 0 114 0 131 0

Specimen Species Jaw Bone Teeth KUM 5042 Platecarpus sp. R. Maxilla 1 t. broke 2 t. broke 3 t. broke 4 absent Tooth Tip 3 -15 36 -7 65 -17 N/A Socket 0 0 36 2 65 0 89 0 KUM 85503 Mosasauridae indet. L. Dentary 1 t. broke 2 abs crush 3 t. chip 4 abs crush Tooth Tip -3 31 N/A 39 32 N/A Socket 0 0 N/A 40 1 N/A L. Dentary 5 Tooth Tip 76 28 Socket 74 0 KUM 85552 Mosasauridae indet. L. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke (likely tylosaurine) Tooth Tip 1 24 39 20 76 45 118 29 Socket 0 0 39 0 76 0 118 0 L. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 0 6 45 13 88 13 126 19 Socket 0 0 46 -2 87 0 127 0 KUM 950 Prognathodon overtoni L. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 1 18 43 12 78 4 116 6 Socket 0 0 41 -2 78 -11 115 -2 (cont.) 5 absent 6 t. broke Tooth Tip N/A 187 16 Socket 153 -12 184 0 R. Maxilla 1 t. broke 2 t. broke 3 absent 4 t. broke Tooth Tip -1 -10 40 -7 N/A 130 -11 Socket 0 0 38 3 83 11 130 5 (cont.) 5 t. broke Tooth Tip 172 -28 Socket 174 0

Specimen Species Jaw Bone Teeth YPM-P4 (temp.) Platecarpus sp. R. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 0 7 24 6 55 4 78 8 Socket 0 0 25 -1 55 0 78 -2 (cont.) 5 t. new 6 t. broke 7 t. broke 8 t. broke Tooth Tip 101 9 128 14 155 8 181 10 Socket 102 -3 129 -4 156 -6 182 -2 (cont.) 9 t. new 10 t. broke 11 t. broke 12 t. broke Tooth Tip 204 8 230 12 252 15 272 12 Socket ### 0 230 3 253 1 270 0 R. Maxilla 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 1 -5 22 -9 52 -9 78 -8 Socket 0 0 22 2 50 2 78 5 (cont.) 5 t. broke 6 t. broke 7 t. broke 8 t. broke Tooth Tip 105 -8 132 -13 160 -18 186 -14 Socket 104 5 131 4 158 4 184 3 (cont.) 9 t. broke 10 t. broke 11 t. broke Tooth Tip 209 -10 233 -9 257 -11 Socket 209 1 231 1 255 0 YPM-P4 4134 unidentified R. Maxilla 1 2 3 4 absent Tooth Tip -5 -24 12 -25 28 -27 N/A Socket 0 0 15 0 34 2 52 2 (cont.) 5 6 absent 7 8 Tooth Tip 66 -28 N/A 103 -29 120 -29 Socket 72 2 89 2 107 2 124 1 (cont.) 9 t. broke Tooth Tip 139 -24 Socket 139 0

Specimen Species Jaw Bone Teeth YPM-P4 4132 unidentifed R. Dentary 1 t. chip 2 absent 3 t. chip 4 Tooth Tip -2 28 N/A 65 25 97 28 Socket 0 0 31 0 64 0 99 0 (cont.) 5 absent 6 7 t. chip Tooth Tip N/A 165 27 191 22 Socket 133 0 153 0 193 0 YPM-P4 4097 Platecarpus ictericus L. Dentary 1 t. broke 2 absent 3 t. broke 4 t. broke (temp.) Tooth Tip 1 15 N/A 48 18 67 11 Socket 0 0 24 0 47 0 63 0 YPM-P4 4123 Platecarpus ictericus R. Dentary 1 2 3 4 Tooth Tip -1 20 15 22 33 23 53 23 Socket 0 0 16 -2 34 -3 56 -5 (cont.) 5 6 t. chip 7 absent 8 Tooth Tip 71 23 93 22 N/A 126 25 Socket 76 -5 97 -5 113 -5 133 -3 (cont.) 9 10 11 t. broke 12 Tooth Tip 144 26 162 27 184 16 193 23 Socket 151 -2 168 0 184 0 198 0 L. Dentary 1 2 3 t. chip 4 Tooth Tip 1 15 13 17 31 17 51 22 Socket 0 0 13 0 32 0 54 0 (cont.) 5 absent 6 t. broke 7 absent 8 t. broke Tooth Tip N/A 94 16 N/A 131 20 Socket 73 1 94 2 113 1 135 0 (cont.) 9 10 t. buried Tooth Tip 150 25 174 9 Socket 154 0 172 0

Specimen Species Jaw Bone Teeth YPM 24904 Plaecarpus coryphaeus L. Maxilla 1 t. broke 2 t. broke 3 w. buried 4 t. buried Tooth Tip -1 -11 22 -22 N/A 73 -22 Socket 0 0 31 2 54 3 73 4 (cont.) 5 t. buried 6 7 t. broke 8 Tooth Tip 91 -24 125 -21 141 -29 157 -30 Socket 105 3 131 3 154 2 177 2 (cont.) 9 t. buried 10 t. buried 11 absent 12 absent Tooth Tip 194 -17 214 -23 N/A N/A Socket 198 2 218 3 240 1 255 0 L. Dentary 1 2 t. broke 3 s. absent 4 t. broke Tooth Tip 3 33 30 31 N/A 76 29 Socket 0 0 26 0 N/A 76 -1 (cont.) 5 abs bur 6 7 t. broke Tooth Tip N/A 125 37 152 24 Socket N/A 126 0 146 0 R. Dentary 1 2 t. broke 3 t. broke 4 t. broke Tooth Tip -6 27 22 33 33 31 70 23 Socket 0 0 24 1 46 -2 66 0 (cont.) 5 t. broke Tooth Tip 87 17 Socket 88 0 HT 1707 (cast) Mosasaurus hoffmani L. Dentary 1 2 absent 3 4 absent Tooth Tip 7 37 N/A 95 54 N/A Socket 0 0 48 -3 95 -6 148 -6 (cont.) 5 6 t. broke Tooth Tip 194 66 251 55 Socket 202 -2 259 0

Specimen Species Jaw Bone Teeth YPM 40350 Clidastes sp. L. Dentary 1 t. broke 2 t. broke 3 4 t. broke Tooth Tip 1 17 23 15 35 22 55 14 Socket 0 0 20 0 36 -1 54 -2 (cont.) 5 s. absent 6 t. broke 7 t. broke 8 absent Tooth Tip N/A 89 15 104 11 N/A Socket N/A 87 -2 102 -3 117 -2 (cont.) 9 t. broke 10 absent 11 t. broke Tooth Tip 132 13 N/A 159 10 Socket 130 -2 144 0 158 0 YPM 40377 Platecarpus sp. R. Dentary 1 2 t. buried 3 t. buried 4 abs bur Tooth Tip 5 21 22 21 44 23 N/A Socket 0 0 20 -1 39 -1 N/A (cont.) 5 t. buried 6 w. buried 7 t. buried 8 t. buried Tooth Tip 82 24 N/A 117 24 135 21 Socket 80 -3 100 -3 116 -2 138 -1 (cont.) 9 t. buried Tooth Tip 155 17 Socket 154 0 YPM 1269 Platecarpus ictericus R. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 0 14 25 13 49 14 71 10 Socket 0 0 26 -3 50 -4 72 -5 (cont.) 5 abs bur 6 t. broke 7 t. broke 8 t. broke Tooth Tip N/A 120 18 144 15 171 19 Socket N/A 120 -4 142 -2 168 -2 (cont.) 9 t. broke 10 t. broke 11 t. broke Tooth Tip 191 12 210 16 231 13 Socket 190 1 211 0 231 0

Specimen Species Jaw Bone Teeth L. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 0 7 18 17 39 17 62 14 Socket 0 0 21 1 40 1 63 -1 (cont.) 5 t. broke 6 t. broke 7 t. broke 8 t. broke Tooth Tip 86 15 110 15 136 16 162 12 Socket 88 -1 113 -1 138 -1 164 -1 (cont.) 9 t. broke 10 t. broke 11 t. broke 12 t. broke Tooth Tip 187 13 211 10 234 12 257 10 Socket 187 0 211 -1 236 -1 258 0 L. Maxilla 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip -1 -15 19 -15 41 -13 65 -12 Socket 0 0 21 0 42 -1 67 2 (cont.) 5 absent 6 t. broke 7 t. broke 8 t. broke Tooth Tip N/A 115 -11 139 -13 163 -8 Socket 91 1 117 3 142 4 165 2 (cont.) 9 t. broke 10 t. broke Tooth Tip 184 -8 211 -12 Socket 188 1 213 0 YPM 4003 Platecarpus ictericus L. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 2 13 21 12 42 8 64 5 Socket 0 0 18 -2 39 -4 60 -4 (cont.) 5 t. broke 6 t. broke 7 t. broke 8 t. broke Tooth Tip 87 7 109 11 130 5 155 11 Socket 83 -5 102 -4 128 -4 150 -3 (cont.) 9 t. broke Tooth Tip 172 19 Socket 171 0

Specimen Species Jaw Bone Teeth YPM 4003 Platecarpus ictericus R. Dentary 1 2 3 t. buried 4 t. buried Tooth Tip 0 25 22 24 42 21 66 25 Socket 0 0 22 -2 42 -4 63 -5 (cont.) 5 t. buried 6 t. buried 7 t. buried 8 Tooth Tip 86 15 109 23 127 12 144 23 Socket 84 -5 105 -4 122 -4 143 0 YPM 24900 Platecarpus ictericus L. Maxilla 1 t. broke 2 t. broke 3 t. broke 4 absent Tooth Tip -1 -8 17 -17 35 -24 N/A Socket 0 0 19 1 42 0 64 2 (cont.) 5 t. broke 6 absent 7 t. broke Tooth Tip 77 -24 N/A 118 -7 Socket 84 1 104 4 120 0 YPM 3998 Platecarpus ictericus L. Maxilla 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip -1 -13 19 -9 33 -20 53 -19 Socket 0 0 19 0 36 0 54 0 (cont.) 5 absent 6 t. broke 7 t. broke Tooth Tip N/A 86 -9 100 -5 Socket 75 2 87 -1 102 0 YPM 3690 Platecarpus ictericus R. Dentary 1 absent 2 t. broke 3 absent 4 t. broke Tooth Tip N/A 24 12 N/A 72 11 Socket 0 0 24 -2 49 -6 70 -6 (cont.) 5 6 absent 7 t. broke 8 absent Tooth Tip 103 4 N/A 143 12 N/A Socket 91 -5 119 -8 142 -6 168 -6 (cont.) 9 t. broke 10 absent 11 t. broke 12 t. broke Tooth Tip 191 8 N/A 233 12 254 14 Socket 193 -3 241 -4 234 0 251 0

Specimen Species Jaw Bone Teeth YPM 24921 Platecarpus ictericus L. Dentary 1 t. buried 2 t. buried 3 abs bur 4 Tooth Tip 1 26 26 29 N/A 72 37 Socket 0 0 24 -1 N/A 70 0 (cont.) 5 abs bur 6 7 abs bur 8 t. broke Tooth Tip N/A 117 37 N/A 160 35 Socket N/A 120 -1 N/A 159 0 L. Maxilla 1 t. broke 2 t. new? 3 abs bur 4 t. buried Tooth Tip 2 -15 15 -21 N/A 63 -29 Socket 0 0 28 1 N/A 65 2 (cont.) 5 t. broke Tooth Tip 85 -27 Socket 89 0 YPM 24929 Platecarpus ictericus L. Maxilla 1 t. broke? 2 t. broke? 3 t. broke? 4 t. broke? Tooth Tip 1 -26 22 -18 42 -18 67 -17 Socket 0 0 18 1 39 1 66 0 YPM 40393 Platecarpus ictericus R. Maxilla 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 2 -6 20 -4 40 -8 67 -14 Socket 0 0 16 0 38 1 64 1 (cont.) 5 t. broke 6 t. broke 7 t. broke Tooth Tip 92 -17 121 -19 144 -22 Socket 89 0 116 2 144 0 L. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 1 16 28 18 49 15 77 11 Socket 0 0 24 0 51 0 77 -1 (cont.) 5 t. broke 6 t. broke 7 t. broke 8 t. broke Tooth Tip 103 13 127 15 151 17 170 6 Socket 102 1 127 2 147 1 168 0

Specimen Species Jaw Bone Teeth YPM 24931 Platecarpus ictericus L. PreMaxilla 1 t. broke 2 3 Tooth Tip 4 -20 17 -29 32 -24 Socket 0 0 19 2 33 0 L. Maxilla 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip -1 -12 21 -16 39 -17 56 -9 Socket 0 0 20 -1 40 1 58 0 R. Maxilla 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 3 -4 16 -3 36 -10 66 -12 Socket 0 0 21 1 42 2 64 0 YPM 3997 Platecarpus sp. R. Maxilla 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 5 -12 32 -11 60 -12 84 -18 Socket 0 0 29 0 56 -1 80 1 (cont.) 5 t. broke 6 t. broke 7 t. broke Tooth Tip 106 -15 131 -12 151 -11 Socket 105 0 128 0 151 0 L. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 1 11 23 11 48 15 71 14 Socket 0 0 22 -1 47 -1 73 -1 (cont.) 5 t. broke 6 absent 7 t. broke 8 t. broke Tooth Tip 98 21 N/A 125 8 146 15 Socket 97 -2 114 -3 128 -3 147 -2 (cont.) 9 t. broke 10 t. broke Tooth Tip 170 17 191 7 Socket 170 -2 187 0 R. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip -1 8 24 14 48 16 70 12 Socket 0 0 22 0 49 -1 71 -1

Specimen Species Jaw Bone Teeth (cont.) 5 t. broke 6 t. broke 7 t. broke Tooth Tip 90 11 102 8 111 9 Socket 91 -1 102 -2 111 0 R. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip -1 8 26 6 40 4 76 5 Socket 0 0 25 1 43 0 74 -2 YPM 1425 Platecarpus sp. L. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 1 5 31 9 50 11 75 14 Socket 0 0 24 0 48 -1 74 -1 (cont.) 5 t. broke Tooth Tip 99 20 Socket 99 0 L. Maxilla 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip -1 -23 23 -5 45 -17 67 -11 Socket 0 0 26 1 45 3 68 0 YPM 40948 Platecarpus sp. ? 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip -3 9 12 9 34 6 50 8 Socket 0 0 16 0 35 0 52 0 (cont.) 5 t. broke Tooth Tip 72 8 Socket 74 0 YPM 24905 Platecarpus sp. Left Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 0 12 18 15 36 9 53 4 Socket 0 0 18 0 36 0 54 0 ? 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 0 8 19 6 40 9 61 8 Socket 0 0 19 0 39 0 60 0

Specimen Species Jaw Bone Teeth YPM 40439 Platecarpus sp. L. Maxilla 1 t. broke 2 t. broke 3 4 Tooth Tip -1 -8 19 -13 49 -10 64 -28 Socket 0 0 21 0 49 3 67 0 (cont.) 5 t. broke 6 t. broke 7 t. broke 8 t. broke Tooth Tip 92 -3 114 -18 134 -17 157 -18 Socket 92 0 114 0 136 1 157 2 (cont.) 9 t. broke 10 t. broke 11 t. broke Tooth Tip 178 -5 197 -11 216 -10 Socket 180 2 199 1 218 0 L. Dentary 1 t. broke 2 absent 3 t. broke 4 t. broke Tooth Tip 2 12 N/A 48 3 72 16 Socket 0 0 26 -2 47 -1 67 0 (cont.) 5 absent 6 t. broke 7 t. broke Tooth Tip N/A 106 21 124 13 Socket 87 0 105 0 121 0 R. Dentary 1 t. broke 2 t. broke 3 t. broke 4 absent Tooth Tip -1 11 24 13 54 14 N/A Socket 0 0 26 1 54 4 79 4 (cont.) 5 t. broke 6 t. broke Tooth Tip 95 11 105 12 Socket 98 2 105 0 YPM 40440 Platecarpus sp. R. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip -1 12 22 13 42 8 65 11 Socket 0 0 23 0 44 1 67 0 (cont.) 5 t. broke Tooth Tip 86 9 Socket 87 0

Specimen Species Jaw Bone Teeth YPM 40445 Platecarpus sp. R. Dentary 1 t. broke 2 t. broke 3 4 t. broke Tooth Tip 0 6 19 5 42 5 56 6 Socket 0 0 19 0 38 -1 55 -2 (cont.) 5 t. broke Tooth Tip 74 7 Socket 74 0 YPM 40460 Platecarpus sp. R. Dentary 1 t. broke 2 t. broke 3 abs bur 4 Tooth Tip -6 8 10 11 N/A 53 18 Socket 0 0 17 -2 N/A 54 -3 (cont.) 5 absent 6 7 8 abs bur Tooth Tip N/A 92 21 116 22 N/A Socket 76 -4 96 -3 117 -5 N/A (cont.) 9 t. broke 10 t. broke 11 t. broke 12 t. broke Tooth Tip 153 9 172 12 189 7 204 5 Socket 154 -3 172 0 190 0 206 0 YPM 40436 Platecarpus sp. R. Maxilla 1 t. broke 2 t. broke 3 absent 4 t. broke Tooth Tip 2 -18 22 -19 N/A 74 -20 Socket 0 0 26 0 52 0 74 1 (cont.) 5 t. broke 6 absent 7 t. broke 8 t. broke Tooth Tip 102 -24 N/A 149 -21 171 -18 Socket 97 1 128 1 148 1 170 0 (cont.) 9 t. broke 10 t. broke Tooth Tip 191 -18 210 -21 Socket 191 0 211 0 L. Maxilla 1 2 abs bur 3 t. broke 4 Tooth Tip -1 -10 N/A 34 -16 56 -24 Socket 0 0 N/A 37 0 62 0

Specimen Species Jaw Bone Teeth YPM 40436 Platecarpus sp. (cont.) 5 6 absent 7 t. broke 8 absent Tooth Tip 84 -27 N/A 136 -23 N/A Socket 86 0 112 0 134 2 159 2 (cont.) 9 10 abs bur 11 12 Tooth Tip 179 -32 N/A 223 -31 240 -28 Socket 184 1 N/A 227 2 247 0 R. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 3 10 21 8 47 3 68 8 Socket 0 0 22 -3 48 -5 71 -7 (cont.) 5 t. broke 6 t. broke 7 t. broke 8 absent Tooth Tip 93 13 122 5 140 11 N/A Socket 95 -8 123 -8 146 -6 164 -5 (cont.) 9 t. broke 10 t. broke 11 t. broke 12 t. broke Tooth Tip 185 8 206 15 225 13 246 11 Socket 186 -3 208 0 228 0 244 0 L. Dentary 1 t. buried 2 t. buried 3 s. absent 4 Tooth Tip 1 8 25 19 N/A 71 21 Socket 0 0 23 -2 N/A 71 -4 (cont.) 5 s. broke 6 t. broke 7 absent 8 t. broke Tooth Tip N/A 117 12 N/A 158 11 Socket N/A 118 -3 139 -3 159 -2 (cont.) 9 t. broke 10 t. broke Tooth Tip 179 13 193 10 Socket 180 0 195 0 YPM 1318 Clidastes propython R. Dentary 1 t. broke 2 absent 3 4 t. broke Tooth Tip 2 6 N/A 39 19 59 13 Socket 0 0 21 -2 39 -2 59 -2

Specimen Species Jaw Bone Teeth YPM 1318 Clidastes propython (cont.) 5 6 absent 7 t. broke 8 Tooth Tip 79 16 N/A 119 18 134 18 Socket 79 -2 100 -2 119 -2 136 -2 (cont.) 9 10 11 abs bur 12 t. broke Tooth Tip 152 20 169 19 N/A 208 19 Socket 154 -2 171 -1 N/A 204 -1 (cont.) 13 t. broke 14 t. broke 15 absent 16 t. broke Tooth Tip 219 5 237 10 N/A 268 8 Socket 220 -1 236 -1 247 -1 266 -1 (cont.) 17 t. broke 18 t. broke Tooth Tip 279 5 292 5 Socket 278 -1 291 0 L. Dentary 1 2 abs bur 3 t. broke 4 t. broke Tooth Tip 0 15 N/A 37 14 58 12 Socket 0 0 N/A 37 -1 58 -1 (cont.) 5 abs bur 6 7 t. broke 8 abs bur Tooth Tip N/A 94 20 117 12 N/A Socket N/A 96 -1 116 -1 N/A (cont.) 9 t. broke 10 11 12 Tooth Tip 156 14 170 20 187 21 204 19 Socket 153 0 170 0 187 0 203 0 (cont.) 13 abs bur 14 Tooth Tip N/A 234 18 Socket N/A 233 0 YPM 1335 Clidastes liodontus L. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 1 8 16 8 29 8 44 4 Socket 0 0 15 0 29 0 43 0

Specimen Species Jaw Bone Teeth YPM 1335 Clidastes liodontus (cont.) 5 absent 6 t. broke 7 t. broke 8 t. broke Tooth Tip N/A 69 7 82 8 95 2 Socket 54 0 68 0 81 0 94 -1 (cont.) 9 t. broke 10 t. broke 11 absent 12 t. broke Tooth Tip 107 8 120 10 N/A 140 10 Socket 106 -1 118 0 128 0 140 0 (cont.) 13 absent 14 t. broke Tooth Tip N/A 156 10 Socket 149 0 156 0 R. Maxilla 1 t. broke 2 absent 3 t. broke 4 t. broke Tooth Tip 1 -7 N/A 26 -9 38 -7 Socket 0 0 11 1 25 1 37 1 R. Maxilla 5 absent 6 t. broke 7 absent 8 Tooth Tip N/A 61 -6 N/A 79 -6 Socket 48 1 59 1 70 0 78 0 YPM 40479 Platecarpus sp. L. Maxilla 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip -2 -16 21 10 48 -21 76 -16 Socket 0 0 25 0 51 1 78 0 (cont.) 5 t. broke 6 t. broke 7 t. broke 8 t. broke Tooth Tip 102 -12 131 -20 152 -20 175 -18 Socket 105 2 133 2 154 1 177 0 (cont.) 9 t. broke Tooth Tip 196 -12 Socket 198 0 YPM 1335 Clidastes liodontus R. Dentary 1 t. Broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 0 11 14 11 27 10 41 11 Socket 0 0 15 0 28 0 41 0

Specimen Species Jaw Bone Teeth YPM 1335 Clidastes liodontus (cont.) 5 t. broke Tooth Tip 54 6 Socket 55 0 R. Dentary 1 t. broke 2 absent 3 t. broke 4 t. broke Tooth Tip 0 12 N/A 24 9 35 6 Socket 0 0 11 0 23 0 35 0 (cont.) 5 t. broke 6 7 absent 8 t. broke Tooth Tip 46 8 54 11 N/A 72 3 Socket 46 0 56 0 64 0 73 0 YPM 40508 Platecarpus sp. L. Maxilla 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip -1 -11 24 -15 48 -15 68 -15 Socket 0 0 25 0 48 0 70 0 (cont.) 5 t. broke 6 absent Tooth Tip 88 -7 N/A Socket 91 0 110 0 L. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 0 15 21 12 43 15 61 12 Socket 0 0 20 0 41 1 60 0 (cont.) 5 t. broke Tooth Tip 78 5 Socket 77 0 YPM 40472 Platecarpus sp. L. Dentary 1 2 t. broke 3 t. broke 4 abs bur Tooth Tip 3 24 24 19 42 21 N/A Socket 0 0 22 0 43 0 N/A (cont.) 5 Tooth Tip 83 26 Socket 83 0

Specimen Species Jaw Bone Teeth YPM 40564 Platecarpus sp. R. Maxilla 1 t. broke 2 3 t. broke 4 Tooth Tip 4 -24 28 -33 64 -25 88 -27 Socket 0 0 33 0 64 0 91 0 (cont.) 5 t. broke 6 abs bur 7 t. broke 8 t. broke Tooth Tip 119 -19 N/A 176 -18 201 -9 Socket 122 1 N/A 176 0 202 3 YPM 40586 Platecarpus sp. L. Maxilla 1 t. broke 2 t. broke 3 4 t. broke Tooth Tip 1 12 21 26 37 31 60 18 Socket 0 0 24 0 43 0 62 0 YPM 40613 Platecarpus sp. L. Maxilla 1 2 t. broke 3 4 t. chip Tooth Tip -4 -9 12 -18 30 -25 48 -28 Socket 0 0 14 -1 31 -1 53 0 (cont.) 5 absent 6 t. chip 7 t. chip 8 Tooth Tip N/A 92 -32 113 -33 135 -35 Socket 73 0 94 1 117 0 141 0 YPM 40654 Platecarpus sp. R. Dentary 1 t. broke 2 absent 3 t. broke 4 t. broke Tooth Tip 0 12 N/A 42 13 66 13 Socket 0 0 16 -1 42 0 67 0 R. Dentary 5 t. broke 6 t. broke Tooth Tip 90 22 113 21 Socket 89 0 113 0 YPM 40509 Platecarpus sp. R. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 0 6 21 11 40 11 67 7 Socket 0 0 22 0 43 2 68 3 (cont.) 5 t. broke 6 t. broke Tooth Tip 87 13 111 15 Socket 91 0 116 0

Specimen Species Jaw Bone Teeth YPM 40518 Platecarpus sp. L. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 1 12 24 15 42 15 62 13 Socket 0 0 21 1 41 2 61 2 (cont.) 5 t. broke 6 absent Tooth Tip 81 15 N/A Socket 79 3 92 0 R. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 0 12 19 11 38 14 58 12 Socket 0 0 22 0 40 0 59 0 (cont.) 5 t. broke Tooth Tip 78 13 Socket 77 0 YPM 40550 Platecarpus sp. R. Maxilla 1 2 t. chip 3 abs bur 4 Tooth Tip -1 -15 13 -20 N/A 42 -24 Socket 0 0 11 1 N/A 45 3 (cont.) 5 6 abs bur 7 t. broke 8 Tooth Tip 62 -28 N/A 98 -11 110 -31 Socket 63 3 N/A 99 2 120 0 YPM 40653 Platecarpus sp. L. Dentary 1 t. broke 2 absent 3 t. broke 4 t. broke Tooth Tip 4 10 N/A 42 19 59 7 Socket 0 0 16 -2 39 -2 57 -1 (cont.) 5 t. broke 6 t. broke 7 absent 8 t. broke Tooth Tip 76 14 97 16 N/A 136 18 Socket 75 -1 95 -1 114 0 132 0 (cont.) 9 t. broke 10 absent 11 t. broke Tooth Tip 153 16 N/A 185 7 Socket 150 0 186 0 179 0

Specimen Species Jaw Bone Teeth YPM 40462 Platecarpus sp. R. Dentary 1 2 3 4 t. broke Tooth Tip -4 21 21 24 41 25 71 14 Socket 0 0 24 -1 46 -2 70 -2 (cont.) 5 t. broke 6 7 t. broke 8 absent Tooth Tip 96 10 116 26 145 17 N/A Socket 96 -2 119 -3 147 -3 176 -3 (cont.) 9 t. broke 10 absent 11 12 Tooth Tip 190 26 N/A 240 33 257 28 Socket 196 -3 218 0 238 0 254 0 L. Dentary 1 2 3 4 Tooth Tip -2 21 25 18 40 28 69 27 Socket 0 0 21 -2 42 -3 69 -4 (cont.) 5 abs bur 6 abs bur 7 8 Tooth Tip N/A N/A 143 28 170 29 Socket N/A N/A 146 -3 171 -2 (cont.) 9 10 t. chip 11 Tooth Tip 195 30 218 29 242 30 Socket 193 -1 217 0 233 0 YPM 40728 Platecarpus sp. L. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 1 8 25 8 44 2 69 2 Socket 0 0 24 -2 45 -3 69 -4 (cont.) 5 t. broke 6 t. broke 7 absent 8 t. broke Tooth Tip 90 5 112 4 N/A 157 8 Socket 91 -4 112 -4 135 -2 155 -1 (cont.) 9 t. broke 10 t. broke 11 t. broke 12 t. broke Tooth Tip 178 12 199 11 217 11 233 4 Socket 179 0 199 0 216 1 232 0

Specimen Species Jaw Bone Teeth YPM 40817 Platecarpus sp. L. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 1 11 24 16 44 10 65 11 Socket 0 0 21 0 42 0 63 0 (cont.) 5 t. broke 6 t. broke 7 t. broke 8 t. broke Tooth Tip 87 8 109 16 131 14 152 11 Socket 86 0 107 1 128 2 148 2 (cont.) 9 t. broke 10 t. broke 11 t. broke Tooth Tip 171 12 189 11 207 9 Socket 170 2 185 1 204 0 YPM 40734 Platecarpus sp. R. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip -1 9 20 12 46 13 70 14 Socket 0 0 21 -1 45 -2 71 -1 (cont.) 5 absent 6 t. broke 7 t. broke Tooth Tip N/A 121 14 145 15 Socket 93 -1 121 0 146 0 YPM 3977 Tylosaurus proriger R. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 4 1 19 8 53 5 83 6 Socket 0 0 23 -1 54 -2 82 -2 (cont.) 5 absent 6 t. broke 7 t. broke 8 t. broke Tooth Tip N/A 135 7 167 21 187 17 Socket 107 -4 136 -3 169 -1 189 -1 (cont.) 9 t. broke Tooth Tip 217 17 Socket 218 0 YPM 3978 Tylosaurus proriger L. Dentary 1 t. broke 2 t. broke 3 t. broke Tooth Tip 0 18 39 23 73 10 Socket 0 0 37 0 69 0

Specimen Species Jaw Bone Teeth YPM 4002 Tylosaurus proriger ? Dentary 1 t. broke 2 t. broke Tooth Tip -3 43 45 32 Socket 0 0 46 0 YPM 3969 Tylosaurus proriger R. Maxilla 1 t. broke 2 t. broke 3 absent 4 t. broke Tooth Tip 1 12 30 6 N/A 93 16 Socket 0 0 30 0 60 -1 91 0 (cont.) 5 t. broke 6 t. broke 7 t. broke 8 absent Tooth Tip 126 15 155 15 181 18 N/A Socket 123 0 151 -2 181 0 209 -2 (cont.) 9 t. chip 10 t. broke 11 t. broke 12 t. broke Tooth Tip 232 25 264 18 287 18 313 8 Socket 236 0 263 -2 287 0 312 0 YPM 3970 Tylosaurus proriger L. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 2 20 44 23 77 24 113 15 Socket 0 0 40 0 73 0 111 0 YPM 3999 Tylosaurus proriger R. Dentary 1 t. broke 2 absent 3 t. broke 4 t. broke Tooth Tip -3 10 N/A 64 11 97 9 Socket 0 0 30 -1 64 -4 98 -6 (cont.) 5 absent 6 t. broke 7 t. broke 8 t. broke Tooth Tip N/A 165 7 203 6 239 9 Socket 133 -8 167 -8 204 -7 237 -4 (cont.) 9 t. broke 10 t. broke 11 t. broke 12 t. broke Tooth Tip 274 9 297 4 335 6 367 8 Socket 272 -3 304 -4 334 0 364 0 (cont.) 13 t. broke Tooth Tip 393 7 Socket 394 0

Specimen Species Jaw Bone Teeth YPM 3999 Tylosaurus proriger L. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 3 6 39 8 72 9 109 9 Socket 0 0 38 0 70 -2 106 -2 (cont.) 5 absent 6 t. broke 7 t. broke 8 t. broke Tooth Tip N/A 178 11 213 12 244 13 Socket 141 -5 175 -3 209 -1 241 -1 (cont.) 9 t. broke 10 absent Tooth Tip 272 10 N/A Socket 271 0 297 0 YPM 1291 Tylosaurus sp. L. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 1 9 20 7 39 7 58 5 Socket 0 0 18 0 38 -1 56 -1 (cont.) 5 t. broke 6 t. broke 7 t. broke Tooth Tip 77 12 95 6 111 8 Socket 76 -1 94 0 110 0 YPM 40762 Tylosaurus sp. R. Maxilla 1 t. buried 2 t. broke 3 t. broke Tooth Tip -6 41 25 41 51 35 Socket 0 0 27 0 58 0 YPM 40764 Tylosaurus sp. R. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 1 20 42 19 66 11 107 19 Socket 0 0 40 0 64 0 102 0 (cont.) 5 t. broke 6 t. broke 7 t. broke 8 t. broke Tooth Tip 117 10 142 10 164 17 200 11 Socket 122 5 136 0 164 0 194 0 L. Max and YPM 40767 Tylosaurus sp. Premax 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 4 -18 38 -23 70 -6 105 -10 Socket 0 0 34 1 71 2 103 0

Specimen Species Jaw Bone Teeth YPM 40764 Tylosaurus sp. (cont.) 5 t. broke Tooth Tip 138 -8 Socket 134 0 YPM 3974 Tylosaurus nepaeolicus R. Maxilla 1 t. broke 2 t. chip 3 absent 4 t. broke Tooth Tip -3 -18 26 -26 N/A 78 -29 Socket 0 0 30 0 48 -4 81 0 (cont.) 5 w. buried 6 t. chip 7 t. chip 8 t. chip Tooth Tip N/A 133 -32 160 -31 186 -31 Socket 112 0 134 0 162 -1 189 0 (cont.) 9 t. chip 10 t. chip Tooth Tip 214 -29 234 -26 Socket 213 0 234 0 L. Maxilla 1 absent 2 t. chip 3 t. broke 4 t. chip Tooth Tip N/A 22 -28 48 -28 77 -29 Socket 0 0 28 0 54 0 80 0 (cont.) 5 6 Tooth Tip 99 -31 125 -32 Socket 107 0 132 0 YPM 40782 Tylosaurus sp. L. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 0 18 35 18 69 15 104 18 Socket 0 0 32 0 67 -4 102 0 (cont.) 5 t. broke 6 t. broke 7 t. broke 8 t. broke Tooth Tip 142 8 177 8 195 17 243 4 Socket 138 -2 172 0 204 1 242 0 YPM 40770 Tylosaurus sp. L. Dentary 1 t. broke 2 absent 3 t. broke 4 t. broke Tooth Tip 1 9 N/A 39 9 68 15 Socket 0 0 19 0 39 0 63 -1

Specimen Species Jaw Bone Teeth YPM 40770 Tylosaurus sp. (cont.) 5 t. broke 6 t. broke Tooth Tip 81 11 101 10 Socket 80 0 101 0 YPM 40787 Tylosaurus sp. R. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. buried Tooth Tip -2 23 34 21 64 30 97 27 Socket 0 0 36 0 64 -1 99 -1 (cont.) 5 6 t. broke Tooth Tip 133 35 165 22 Socket 135 -1 162 0 YPM 40802 Tylosaurus sp. L. Dentary 1 t. broke 2 t. broke 3 t. broke 4 Tooth Tip -4 17 19 44 64 24 94 35 Socket 0 0 39 0 76 -4 120 -2 (cont.) 5 s. absent 6 Tooth Tip N/A 169 27 Socket N/A 178 0 R. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip -3 22 42 35 83 43 115 29 Socket 0 0 42 0 79 0 117 -2 (cont.) 5 6 s. absent 7 Tooth Tip 154 45 N/A 208 32 Socket 154 -2 N/A 225 0 YPM 40785 Tylosaurus sp. L. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 1 15 37 13 71 9 95 21 Socket 0 0 37 0 66 0 92 1 (cont.) 5 t. broke 6 7 t. broke 8 absent Tooth Tip 126 21 143 8 179 19 N/A Socket 126 -1 150 -2 178 0 204 1

Specimen Species Jaw Bone Teeth YPM 40785 Tylosaurus sp. (cont.) 9 Tooth Tip 239 8 Socket 233 0 R. Dentary 1 t. broke 2 t. broke 3 absent 4 t. broke Tooth Tip 0 15 35 19 N/A 93 12 Socket 0 0 35 0 66 0 94 -1 (cont.) 5 t. broke 6 7 t. broke 8 t. broke Tooth Tip 123 11 148 9 178 12 204 12 Socket 123 0 147 -1 177 2 205 3 (cont.) 9 Tooth Tip 238 8 Socket 227 0 YPM 2062 unidentified R. Maxilla 1 2 3 4 Tooth Tip 0 -31 25 -10 22 -31 83 -53 Socket 0 0 30 0 47 0 83 3 (cont.) 5 t. broke Tooth Tip 136 -49 Socket 132 0 YPM 1153 unidentified R. Maxilla 1 t. broke 2 t. broke 3 t. broke 4 absent Tooth Tip 4 -21 39 -21 73 -12 N/A Socket 0 0 36 0 72 4 105 2 (cont.) 5 t. broke Tooth Tip 134 -25 Socket 136 0 L. Dentary 1 t. broke 2 t. broke 3 s. absent 4 t. broke Tooth Tip 2 15 37 22 N/A 101 19 Socket 0 0 37 0 N/A 99 1

Specimen Species Jaw Bone Teeth YPM 1153 unidentified (cont.) 5 t. broke Tooth Tip 141 21 Socket 139 0 YPM-PU 17249 Clidastes liodontus L. Dentary 1 t. broke 2 t. broke 3 4 Tooth Tip 4 4 17 6 30 13 49 12 Socket 0 0 13 -2 31 -3 51 -4 (cont.) 5 t. broke 6 t. broke 7 absent 8 Tooth Tip 64 9 84 1 N/A 110 14 Socket 64 -5 83 -4 100 -4 113 -4 (cont.) 9 10 t. broke 11 t. broke 12 Tooth Tip 127 13 143 9 158 8 172 11 Socket 130 -2 142 -2 157 -2 171 -2 (cont.) 13 t. broke Tooth Tip 183 8 Socket 182 0 R. Maxilla 1 t. broke 2 3 absent 4 Tooth Tip 2 -8 14 -17 N/A 40 -17 Socket 0 0 15 0 28 3 42 0 (cont.) 5 absent 6 7 absent Tooth Tip N/A 67 -15 N/A Socket 54 2 67 1 77 0 L. Maxilla 1 t. broke 2 3 4 Tooth Tip 1 -5 15 -12 24 -13 43 -16 Socket 0 0 15 1 27 2 46 1 (cont.) 5 absent 6 t. broke 7 t. broke 8 absent Tooth Tip N/A 79 -9 96 -8 N/A Socket 62 2 79 2 97 0 111 1

Specimen Species Jaw Bone Teeth YPM-PU 17249 Clidastes liodontus (cont.) 9 t. broke Tooth Tip 127 -5 Socket 128 0 YPM-PU 11173 Mosasaurus sp. L. Dentary 1 t. broke 2 abs bur 3 4 t. broke Tooth Tip 0 25 N/A 47 33 49 26 Socket 0 0 N/A 50 0 50 0 AMNH 14788 Platecarpus sp. R. Maxilla 1 t. chip 2 3 t. broke 4 absent Tooth Tip 2 -22 31 -25 43 -21 N/A Socket 0 0 18 0 4 -1 66 0 (cont.) 5 6 t. crack 7 8 t. chip Tooth Tip 82 -35 112 -35 130 -37 157 -35 Socket 90 -1 113 0 136 0 158 0 (cont.) 9 10 t. broke Tooth Tip 180 -35 201 -16 Socket 177 0 202 0 L. Maxilla 1 t. chip 2 absent 3 4 t. chip Tooth Tip -6 -31 N/A 41 -34 68 -32 Socket 0 0 24 0 47 1 70 2 (cont.) 5 t. broke 6 t. chip 7 t. broke Tooth Tip 91 -27 110 -30 132 -19 Socket 91 2 112 1 131 0 R. Dentary 1 2 t. broke 3 absent 4 Tooth Tip 0 30 28 23 N/A 75 30 Socket 0 0 25 0 49 0 74 0 (cont.) 5 absent 6 t. broke 7 t. broke Tooth Tip N/A 123 26 141 19 Socket 95 0 119 0 137 0

Specimen Species Jaw Bone Teeth AMNH 2155 Platecarpus sp. L. Dentary 1 t. chip 2 t. broke 3 t. broke Tooth Tip -1 21 17 20 39 18 Socket 0 0 18 0 38 0 AMNH 2160 Tylosaurus proriger R. Dentary 1 absent 2 t. broke 3 t. broke 4 t. broke Tooth Tip N/A 11 4 32 6 43 6 Socket 0 0 12 0 32 0 43 -1 (cont.) 5 t. broke Tooth Tip 61 5 Socket 61 0 L. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip -2 5 19 6 33 6 51 5 Socket 0 0 20 -4 32 -1 51 0 AMNH 134 Tylosaurus nepaeolicus R. Dentary 1 t. chip 2 t. chip 3 4 Tooth Tip -4 29 19 29 46 21 81 18 Socket 0 0 23 -1 52 -7 84 -11 (cont.) 5 6 7 8 t. broke Tooth Tip 109 20 136 19 172 20 204 12 Socket 114 -12 142 -12 178 -10 207 -10 (cont.) 9 10 11 12 Tooth Tip 231 22 248 0 256 18 286 24 Socket 236 -8 256 -5 264 -5 290 -4 (cont.) 13 t. broke 14 t. broke Tooth Tip 313 5 335 8 Socket 315 -1 336 0 L. Dentary 1 2 3 4 Tooth Tip -6 20 16 26 39 28 65 18 Socket 0 0 21 -2 44 -4 69 -8

Specimen Species Jaw Bone Teeth AMNH 134 Tylosaurus nepaeolicus (cont.) 5 6 7 t. chip 8 Tooth Tip 99 20 131 19 158 18 190 21 Socket 106 -10 135 -11 163 -9 196 -10 (cont.) 9 10 11 12 Tooth Tip 219 21 249 22 281 20 304 21 Socket 228 -11 255 -9 285 -5 308 -4 (cont.) 13 14 Tooth Tip 329 19 350 18 Socket 333 -2 354 0 AMNH 4909 Tylosaurus proriger L. Maxilla 1 t. broke 2 t. chip 3 absent 4 t. chip Tooth Tip -2 -19 26 -22 N/A 75 -24 Socket 0 0 31 1 52 1 79 2 (cont.) 5 6 absent 7 8 t. chip Tooth Tip 103 -25 N/A 152 -26 188 -25 Socket 109 3 135 1 163 1 189 0 R. Dentary 1 t. broke 2 t. broke 3 absent 4 t. broke Tooth Tip -1 13 38 11 N/A 81 7 Socket 0 0 38 -2 64 -3 81 -6 (cont.) 5 t. broke 6 absent 7 t. broke 8 t. broke Tooth Tip 116 12 N/A 166 16 196 14 Socket 116 -4 145 -2 165 -3 195 -2 (cont.) 9 10 t. broke 11 t. broke 12 absent Tooth Tip 224 9 243 9 266 10 N/A Socket 223 -4 243 0 266 0 287 0 AMNH 1560 Tylosaurus proriger R. Maxilla 1 t. broke 2 t. broke 3 t. broke Tooth Tip 3 -24 38 -22 69 -22 Socket 0 0 35 0 68 0

Specimen Species Jaw Bone Teeth AMNH 1807 Platecarpus ictericus R. Dentary 1 t. broke 2 absent 3 t. broke 4 t. broke Tooth Tip 0 7 N/A 32 12 53 18 Socket 0 0 16 -2 34 -1 53 -1 (cont.) 5 abs bur 6 t. broke Tooth Tip N/A 92 18 Socket N/A 93 0 L. Dentary 1 2 3 4 t. chip Tooth Tip 1 21 15 23 32 24 52 25 Socket 0 0 18 -1 34 -1 54 0 AMNH 6159 Platecarpus ictericus R. Maxilla 1 2 t. broke 3 absent 4 t. broke Tooth Tip -4 -13 12 -20 N/A 50 -25 Socket 0 0 16 0 35 5 60 8 (cont.) 5 6 absent 7 t. broke 8 Tooth Tip 70 -31 N/A 118 -24 136 -31 Socket 78 7 103 6 125 5 151 6 (cont.) 9 absent 10 11 Tooth Tip N/A 190 -29 213 -28 Socket 180 2 202 0 225 0 AMNH 1820 Platecarpus ictericus L. PreMaxilla 1 t. broke 2 t. broke Tooth Tip 1 -12 19 -10 Socket 0 0 16 0 R. PreMaxilla 1 t. broke 2 Tooth Tip 2 -12 20 -27 Socket 0 0 18 0 PreMaxilla (front) 1 ? 2 ? Tooth Tip -1 12 8 23 Socket 0 0 12 0

Specimen Species Jaw Bone Teeth AMNH 1820 Platecarpus ictericus R. Maxilla 1 t. broke 2 t. broke 3 absent 4 Tooth Tip 0 -17 22 -14 N/A 61 -29 Socket 0 0 21 2 44 4 65 3 (cont.) 5 6 absent 7 t. broke 8 Tooth Tip 85 -31 N/A 132 -23 147 -30 Socket 89 3 114 4 136 3 161 2 (cont.) 9 t. chip 10 t. chip 11 absent Tooth Tip 173 -29 195 -30 N/A Socket 182 1 203 0 222 0 L. Maxilla 1 2 t. chip 3 absent 4 t. chip Tooth Tip -1 -21 20 -22 N/A 65 -27 Socket 0 0 22 3 46 4 68 4 (cont.) 5 t. broke 6 absent 7 8 t. chip Tooth Tip 90 -22 N/A 129 -29 153 -32 Socket 93 5 114 6 140 4 164 3 (cont.) 9 t. chip 10 Tooth Tip 177 -32 193 -33 Socket 186 1 207 0 AMNH 1821 Platecarpus ictericus L. Dentary 1 2 absent 3 absent 4 Tooth Tip 0 22 N/A N/A 47 27 Socket 0 0 13 0 25 0 45 0 (cont.) 5 t. chip 6 absent 7 t. broke 8 t. broke Tooth Tip 69 25 N/A 115 21 139 8 Socket 68 0 89 0 114 0 138 -1 (cont.) 9 absent 10 t. broke 11 absent 12 t. broke Tooth Tip N/A 186 15 N/A 230 15 Socket 161 -1 184 1 205 1 224 0

Specimen Species Jaw Bone Teeth AMNH 1821 Platecarpus ictericus (cont.) 13 t. broke Tooth Tip 247 14 Socket 240 0 R. Dentary 1 rebuilt 2 t. broke 3 t. broke 4 t. broke Tooth Tip -1 26 23 6 44 17 68 11 Socket 0 0 23 0 45 -1 69 -2 (cont.) 5 t. broke 6 absent 7 t. broke 8 absent Tooth Tip 94 6 N/A 139 9 N/A Socket 93 -2 117 -3 140 0 159 -1 (cont.) 9 t. chip 10 t. broke Tooth Tip 183 28 200 18 Socket 180 0 197 0 AMNH 2183 Platecarpus ictericus L. Maxilla 1 ?t. broke 2 ?t. broke 3 ?t. broke 4 ?t. broke Tooth Tip 0 -9 16 -11 35 -16 51 -13 Socket 0 0 17 0 35 0 52 0 (cont.) 5 absent 6 ?t. broke 7 ?t. broke 8 absent Tooth Tip N/A 87 -12 108 -23 N/A Socket 71 1 90 1 109 2 128 2 (cont.) 9 ?t. broke 10 ?t. broke 11 absent 12 ?t. broke Tooth Tip 146 -17 169 -18 N/A 196 -8 Socket 146 2 165 1 189 -1 196 0 AMNH 1588 Platecarpus ictericus L. Dentary 1 ?t. broke 2 absent 3 absent 4 ?t. broke Tooth Tip 1 10 N/A N/A 63 6 Socket 0 0 18 -2 38 -2 62 -2 (cont.) 5 ?t. broke 6 ?t. broke 7 absent 8 ?t. broke Tooth Tip 84 11 102 7 N/A 136 8 Socket 83 0 99 0 114 1 133 0

Specimen Species Jaw Bone Teeth AMNH 2178 Platecarpus ictericus R. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 0 8 21 13 33 7 52 12 Socket 0 0 19 1 33 0 51 2 (cont.) 5 t. broke 6 t. broke 7 absent Tooth Tip 68 6 83 14 N/A Socket 68 1 82 2 94 0 AMNH 1550 Platecarpus ictericus L. Maxilla 1 2 t. broke 3 t. broke 4 t. broke Tooth Tip 2 -31 27 -16 55 -7 81 -28 Socket 0 0 26 1 55 3 79 4 (cont.) 5 t. broke 6 abs bur 7 t. buried 8 t. broke Tooth Tip 108 -20 N/A 165 -11 196 -31 Socket 110 4 N/A 166 2 196 1 (cont.) 9 10 Tooth Tip 215 -38 243 -38 Socket 221 0 249 0 AMNH 1532 Platecarpus ictericus R. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 1 12 20 13 37 13 57 10 Socket 0 0 19 -1 37 -2 57 -2 (cont.) 5 absent 6 t. broke 7 absent Tooth Tip N/A 94 12 N/A Socket 75 -2 94 -1 110 0 L. Dentary 1 t. broke 2 t. broke 3 abs bur 4 Tooth Tip -1 19 20 12 N/A 58 31 Socket 145 0 17 0 N/A 60 0 (cont.) 5 6 t. broke 7 8 t. chip Tooth Tip 78 29 97 18 112 30 131 27 Socket 79 0 97 0 114 1 130 0

Specimen Species Jaw Bone Teeth AMNH 1532 Platecarpus ictericus (cont.) 9 t. broke Tooth Tip 145 4 Socket 145 0 L. Maxilla 1 t. broke 2 t. broke 3 absent 4 t. broke Tooth Tip 0 -10 18 -9 N/A 58 -10 Socket 0 0 19 1 39 3 59 2 (cont.) 5 absent 6 t. broke 7 t. broke Tooth Tip N/A 94 -12 112 -11 Socket 79 3 97 2 114 0 R. Maxilla 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 2 -5 17 -4 30 -12 54 -5 Socket 0 0 15 3 30 5 51 5 (cont.) 5 t. broke 6 t. broke 7 t. broke 8 absent Tooth Tip 72 -8 91 -8 111 -9 N/A Socket 71 5 90 5 111 3 132 5 (cont.) 9 t. broke 10 t. broke Tooth Tip 149 -10 165 -10 Socket 150 2 165 0 AMNH 1559 Platecarpus ictericus R. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 0 9 21 8 42 7 58 8 Socket 0 0 22 0 42 0 58 0 (cont.) 5 t. broke Tooth Tip 74 8 Socket 74 0 AMNH 202 Platecarpus coryphaeus R. Maxilla 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 1 -6 17 -6 37 -9 60 -9 Socket 0 0 17 1 36 3 60 2

Specimen Species Jaw Bone Teeth AMNH 202 Platecarpus coryphaeus (cont.) 5 absent 6 t. broke 7 t. dissolved 8 t. broke Tooth Tip N/A 106 -12 128 -3 149 -16 Socket 85 2 105 3 128 2 150 3 (cont.) 9 t. broke 10 t. broke 11 t. chip 12 t. broke Tooth Tip 172 -17 191 -15 211 -21 231 -17 Socket 172 3 193 2 213 1 231 0 L. Maxilla 1 t. broke 2 s. broke 3 t. broke 4 t. broke Tooth Tip 1 -9 N/A 46 -11 69 -12 Socket 0 0 23 3 46 2 69 0 (cont.) 5 t. broke 6 t. broke Tooth Tip 90 -12 113 -10 Socket 92 0 114 0 L. Dentary 1 ? 2 ? 3 ? 4 ? Tooth Tip 0 27 27 23 51 29 70 29 Socket 0 0 26 0 48 0 71 0 (cont.) 5 ? 6 ?t. broke 7 ?t. broke 8 ?t. broke Tooth Tip 92 21 115 13 132 10 153 9 Socket 92 -1 114 0 131 1 151 0 R. Dentary 1 t. broke 2 t. broke 3 absent 4 t. broke Tooth Tip 0 10 23 12 N/A 68 12 Socket 0 0 24 0 46 0 69 1 (cont.) 5 s. broke 6 t. broke 7 t. broke Tooth Tip N/A 112 11 131 12 Socket N/A 114 1 132 0 AMNH 1511 Platecarpus coryphaeus L. Dentary 1 absent 2 3 4 t. chip Tooth Tip N/A 26 30 51 30 73 28 Socket 0 0 24 0 50 -1 73 -1

100

Specimen Species Jaw Bone Teeth AMNH 1511 Platecarpus coryphaeus (cont.) 5 t. chip 6 t. broke 7 t. broke 8 t. broke Tooth Tip 99 30 123 22 147 19 163 10 Socket 99 1 121 1 143 2 161 0 AMNH 1510 Platecarpus coryphaeus L. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 1 13 24 13 45 10 67 11 Socket 0 0 23 0 45 1 68 1 (cont.) 5 t. broke 6 absent 7 t. broke Tooth Tip 88 13 N/A 128 8 Socket 89 2 110 2 125 0 AMNH 126 Platecarpus coryphaeus R. Maxilla 1 t. broke 2 t. broke 3 t. broke Tooth Tip -1 -14 24 -15 45 -14 Socket 0 0 25 1 46 0 AMNH 127 Platecarpus coryphaeus R. Dentary 1 t. broke 2 t. broke 3 s. absent 4 t. broke Tooth Tip 1 11 25 7 N/A 72 12 Socket 0 0 25 1 N/A 73 2 (cont.) 5 t. broke 6 t. broke 7 t. broke 8 t. broke Tooth Tip 95 11 117 10 138 7 157 8 Socket 97 2 118 1 138 1 158 0 (cont.) 9 t. broke 10 t. broke Tooth Tip 175 12 193 13 Socket 175 2 192 0 AMNH 1593 Clidastes propython L. Dentary 1 t. broke 2 t. broke 3 s. absent 4 absent Tooth Tip 2 14 20 13 N/A N/A Socket 0 0 18 -1 N/A 56 -2 (cont.) 5 t. broke 6 absent 7 t. broke 8 absent Tooth Tip 82 18 N/A 123 18 N/A Socket 80 -2 101 -2 121 -2 141 -2

101

Specimen Species Jaw Bone Teeth AMNH 1593 Clidastes propython (cont.) 9 t. broke 10 absent 11 t. broke 12 absent Tooth Tip 162 18 N/A 200 6 N/A Socket 161 -2 182 -2 298 -1 215 -1 (cont.) 13 t. broke 14 t. chip 15 t. broke 16 absent Tooth Tip 233 15 249 19 267 11 N/A Socket 233 -1 250 0 266 -1 280 -1 (cont.) 17 t. broke Tooth Tip 293 4 Socket 293 0 L. Maxilla 1 t. chip 2 t. chip 3 t. chip 4 t. chip Tooth Tip -3 -26 18 -26 44 -14 57 -26 Socket 0 0 21 0 46 -2 61 -2 (cont.) 5 6 t. broke 7 8 t. broke Tooth Tip 78 -7 94 -18 112 -6 129 -17 Socket 81 -2 96 -2 112 -1 128 -1 (cont.) 9 10 t. broke Tooth Tip 147 -7 160 -9 Socket 147 0 159 0 AMNH 1513 Clidastes propython R. Maxilla 1 t. chip 2 absent 3 t. broke 4 absent Tooth Tip -3 -19 N/A 26 -14 N/A Socket 0 0 12 1 26 0 40 0 (cont.) 5 t. broke Tooth Tip 54 -8 Socket 53 0 L. Maxilla 1 t. chip 2 t. broke 3 t. broke 4 t. broke Tooth Tip -5 -26 20 -5 39 -24 62 -17 Socket 0 0 20 0 42 -1 62 0

102

Specimen Species Jaw Bone Teeth AMNH 1513 Clidastes propython L. Maxilla 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 1 -13 20 -12 37 -10 53 -7 Socket 0 0 19 0 36 0 52 3 (cont.) 5 t. broke 6 t. broke Tooth Tip 70 -6 85 -5 Socket 70 2 86 0 AMNH 176 Clidastes sp. R. Dentary 1 t. broke 2 t. broke 3 absent 4 t. broke Tooth Tip 1 -10 17 -11 N/A 48 -13 Socket 0 0 17 0 33 1 48 1 (cont.) 5 t. broke 6 7 t. broke 8 t. broke Tooth Tip 65 -12 77 -17 92 -15 108 -12 Socket 64 0 80 0 95 0 110 0 (cont.) 9 t. buried 10 t. buried 11 t. buried Tooth Tip 121 -16 136 -15 144 -15 Socket 124 0 138 0 151 0 R. Maxilla 1 t. buried 2 t. buried 3 t. buried 4 t. buried Tooth Tip -1 -14 13 -15 28 -11 41 -12 Socket 0 0 14 0 29 0 42 0 (cont.) 5 t. buried 6 t. buried 7 t. broke 8 t. broke Tooth Tip 52 -14 66 -9 76 -12 86 -10 Socket 54 0 67 0 76 0 86 0 L. Dentary 1 t. chip 2 t. broke 3 t. broke 4 t. broke Tooth Tip -1 9 13 11 28 12 38 8 Socket 0 0 14 0 28 0 40 0 (cont.) 5 t. broke Tooth Tip 51 16 Socket 52 0

103

Specimen Species Jaw Bone Teeth AMNH 5789 unidentified R. Maxilla 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip -1 -12 16 -5 33 -13 48 -12 Socket 0 0 17 -1 33 0 49 0 L. Maxilla 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 2 -18 19 -12 33 -13 50 -16 Socket 0 0 17 0 31 0 48 0 AMNH 1548 Clidastes liodontus R. Maxilla 1 t. broke 2 t. broke 3 t. broke 4 t. broke Tooth Tip 0 -9 16 -6 36 -8 51 -3 Socket 0 0 16 2 35 3 51 5 (cont.) 5 t. broke 6 absent 7 t. broke 8 t. broke Tooth Tip 71 -2 N/A 107 -10 123 -2 Socket 71 5 89 5 106 3 124 4 (cont.) 9 absent 10 t. broke 11 absent 12 t. broke Tooth Tip N/A 158 -9 N/A 188 -6 Socket 141 4 158 2 173 1 187 1 (cont.) 13 t. broke 14 t. broke 15 t. broke Tooth Tip 202 -9 216 -10 227 -4 Socket 201 0 215 0 226 0 L. Dentary 1 t. broke 2 absent 3 t. broke 4 absent Tooth Tip 1 9 N/A 39 6 N/A Socket 0 0 17 0 38 0 57 0 (cont.) 5 t. broke 6 t. broke 7 t. broke 8 t. broke Tooth Tip 76 7 96 7 112 4 132 6 Socket 75 0 95 0 112 0 131 0 (cont.) 9 absent 10 t. broke 11 t. broke 12 t. broke Tooth Tip N/A 164 5 181 4 195 5 Socket 147 -1 163 0 180 -1 195 -1

104

Specimen Species Jaw Bone Teeth AMNH 1548 Clidastes liodontus (cont.) 13 t. broke 14 t. broke 15 t. broke 16 t. broke Tooth Tip 212 7 225 4 237 6 248 3 Socket 211 -1 225 -2 237 -1 248 -3 (cont.) 17 t. broke Tooth Tip 258 5 Socket 258 0 R. Dentary 1 ? 2 ? 3 ? 4 ? Tooth Tip N/A 16 5 32 3 48 6 Socket 0 0 17 0 33 -1 48 -1 (cont.) 5 ? 6 ? 7 ? 8 ? Tooth Tip 62 5 77 4 91 4 101 5 Socket 63 -1 78 -1 91 0 102 0 (cont.) 9 ? Tooth Tip 111 3 Socket 112 0 AMNH 14799 unidentified L. Dentary 1 t. broke 2 t. broke 3 t. broke 4 t. broke (Tylosaurus sp.) Tooth Tip 3 9 36 13 64 12 94 11 Socket 0 0 34 -1 63 -1 92 0 L. Maxilla 1 t. broke 2 t. broke 3 absent 4 t. broke Tooth Tip 0 -20 33 -18 N/A 95 -15 Socket 0 0 34 1 67 2 96 0 (cont.) 5 t. broke 6 t. broke Tooth Tip 123 -17 152 -12 Socket 123 0 151 0 AMNH 14795 unidentified R. Maxilla 1 2 3 4 (Clidastes sp.) Tooth Tip 0 -5 19 -7 N/A 51 -10 Socket 0 0 18 0 33 0 49 0

105

Specimen Species Jaw Bone Teeth AMNH 14795 unidentified (cont.) 5 6 (Clidastes sp.) Tooth Tip N/A 68 -7 Socket 66 0 66 0 L. Maxilla 1 t. broke 2 t. broke 3 t. broke 4 abs bur Tooth Tip 2 -10 22 -7 44 -7 N/A Socket 0 0 21 0 45 0 N/A (cont.) 5 t. broke 6 t. broke 7 t. broke 8 t. broke Tooth Tip 84 -5 103 -8 123 -7 140 -6 Socket 84 0 103 0 123 0 140 0 (cont.) 9 t. broke Tooth Tip 158 -8 Socket 158 0 AMNH 14787 unidentified R. Maxilla 1 t. broke 2 t. broke 3 t. broke 4 t. broke (Plioplatecarpinae) Tooth Tip 2 -10 24 -11 44 -8 65 -9 Socket 0 0 22 0 42 0 64 0 (cont.) 5 t. broke Tooth Tip 85 -9 Socket 85 0 AMNH 24310 unidentified cast R. Maxilla 1 t. broke 2 t. broke 3 t. broke 4 absent (Plioplatecarpus or Tooth Tip 2 -37 31 -43 69 -24 N/A Platecarpus) Socket 0 0 36 0 68 3 105 1 (cont.) 5 t. broke 6 t. broke Tooth Tip 137 -37 172 -39 Socket 136 0 169 0 AMNH 1486 Clidastes tortor R. Maxilla 1 2 3 4 Tooth Tip -2 -12 7 -12 34 -17 50 -19 Socket 0 0 15 0 38 0 56 0

106

Specimen Species Jaw Bone Teeth AMNH 1486 Clidastes tortor (cont.) 5 6 absent 7 t. broke 8 Tooth Tip 74 -21 N/A 121 -14 136 -21 Socket 77 0 98 0 120 0 139 0 AMNH 6159 Platecarpus ictericus R. Dentary 1 t. broke 2 absent 3 4 t. chip Tooth Tip 0 10 N/A 37 21 63 22 Socket 0 0 19 -3 44 -4 69 -5 (cont.) 5 6 7 absent 8 t. broke Tooth Tip 81 24 106 25 N/A 150 26 Socket 87 -6 114 -6 137 -5 159 -4 (cont.) 9 10 absent 11 t. broke 12 t. broke Tooth Tip 176 28 N/A 224 15 246 12 Socket 183 -4 203 -2 225 0 241 0 AMNH 505 Platecarpus coryphaeus R. Maxilla 1 2 3 s. absent 4 t. broke Tooth Tip 2 -31 26 -30 N/A 69 -18 Socket 0 0 26 1 N/A 71 2 (cont.) 5 s. absent 6 t. broke 7 Tooth Tip N/A 109 -30 127 -33 Socket N/A 115 1 134 0 R. Dentary 1 2 s. absent 3 4 absent Tooth Tip 3 16 N/A 41 21 N/A Socket 0 0 N/A 39 -3 61 -5 (cont.) 5 6 absent 7 8 absent Tooth Tip 88 22 N/A 133 23 N/A Socket 85 -5 106 -5 134 -4 152 -4 (cont.) 9 10 abs bur 11 t. chip 12 Tooth Tip 185 29 N/A 225 26 238 26 Socket 180 -2 N/A 218 0 235 0 107

Table A2: Complete and chipped adjacent tooth pairs. Each coordinate set designates the location of the tips or sockets in a tooth pair. The first two numbers give the x- and y-coordinates of the first tooth and the second two numbers give the x- and y-coordinates of the second tooth. All coordinates are in millimeters.

Specimen Species Jaw Bone Point Coordinate Set Coordinate Set Coordinate Set Coordinate Set YPM-PU 17249 Clidastes liodontus Dentary Tip 30 13 49 12 110 14 127 13 YPM-PU 17249 Clidastes liodontus Dentary Socket 31 -3 51 -4 113 -4 130 -2 YPM 1318 Clidastes propython Dentary Tip 134 18 152 20 152 20 169 19 170 20 187 21 187 21 204 19 YPM 1318 Clidastes propython Dentary Socket 136 -2 154 -2 154 -2 171 -1 170 0 187 0 187 0 203 0 AMNH 1511 Platecarpus coryphaeus Dentary Tip 26 30 51 30 51 30 73 28 73 28 99 30 AMNH 1511 Platecarpus coryphaeus Dentary Socket 24 0 50 -1 50 -1 73 -1 73 -1 99 1 AMNH 506 Platecarpus coryphaeus Dentary Tip 225 26 238 26 AMNH 507 Platecarpus coryphaeus Dentary Socket 218 0 235 0 AMNH 1532 Platecarpus ictericus Dentary Tip 58 31 78 29 112 30 131 27 AMNH 1532 Platecarpus ictericus Dentary Socket 60 0 79 0 114 1 130 0 AMNH 1807 Platecarpus ictericus Dentary Tip 1 21 15 23 15 23 32 24 32 24 52 25 AMNH 1807 Platecarpus ictericus Dentary Socket 0 0 18 -1 18 -1 34 -1 34 -1 54 0 AMNH 1821 Platecarpus ictericus Dentary Tip 47 27 69 25 AMNH 1821 Platecarpus ictericus Dentary Socket 45 0 68 0 AMNH 6159 Platecarpus ictericus Dentary Tip 37 21 63 22 63 22 81 24 81 24 106 25 AMNH 6159 Platecarpus ictericus Dentary Socket 44 -4 69 -5 69 -5 87 -6 87 -6 114 -6 YPM 4003 Platecarpus ictericus Dentary Tip 0 25 22 24 YPM 4003 Platecarpus ictericus Dentary Socket 0 0 22 -2 YPM-P4 4123 Platecarpus ictericus Dentary Tip -1 20 15 22 15 22 33 23 33 23 53 23 53 23 71 23 YPM-P4 4124 Platecarpus ictericus Dentary Socket 0 0 16 -2 16 -2 34 -3 34 -3 56 -5 56 -5 76 -5 YPM-P4 4125 Platecarpus ictericus Dentary Tip 71 23 93 22 126 25 144 26 144 26 162 27 1 15 13 17 YPM-P4 4126 Platecarpus ictericus Dentary Socket 76 -5 97 -5 133 -3 151 -2 151 -2 168 0 0 0 13 0

108

Specimen Species Jaw Bone Point Coordinate Set Coordinate Set Coordinate Set Coordinate Set YPM-P4 4127 Platecarpus ictericus Dentary Tip 13 17 31 17 31 17 51 22 YPM-P4 4128 Platecarpus ictericus Dentary Socket 13 0 32 0 32 0 54 0 YPM 40462 Platecarpus sp. Dentary Tip -4 21 21 24 21 24 41 25 240 33 257 28 -2 21 25 18 YPM 40462 Platecarpus sp. Dentary Socket 0 0 24 -1 24 -1 46 -2 238 0 254 0 0 0 21 -2 YPM 40462 Platecarpus sp. Dentary Tip 25 18 40 28 40 28 69 27 143 28 170 29 170 29 195 30 YPM 40462 Platecarpus sp. Dentary Socket 21 -2 42 -3 42 -3 69 -4 146 -3 171 -2 171 -2 193 -1 YPM 40462 Platecarpus sp. Dentary Tip 195 30 218 29 218 29 242 30 YPM 40462 Platecarpus sp. Dentary Socket 193 -1 217 0 217 0 233 0 YPM 40460 Platecarpus sp. Dentary Tip 92 21 116 22 YPM 40460 Platecarpus sp. Dentary Socket 96 -3 117 -5 AMNH 134 Tylosaurus nepaeolicus Dentary Tip -4 29 19 29 19 29 46 21 46 21 81 18 81 18 109 20 AMNH 134 Tylosaurus nepaeolicus Dentary Socket 0 0 23 -1 23 -1 52 -7 52 -7 84 -11 84 -11 114 -12 AMNH 134 Tylosaurus nepaeolicus Dentary Tip 109 20 136 19 136 19 172 20 231 22 248 0 248 0 256 18 AMNH 134 Tylosaurus nepaeolicus Dentary Socket 114 -12 142 -12 142 -12 178 -10 236 -8 256 -5 256 -5 264 -5 AMNH 134 Tylosaurus nepaeolicus Dentary Tip 256 18 286 24 -6 20 16 26 AMNH 134 Tylosaurus nepaeolicus Dentary Socket 264 -5 290 -4 0 0 21 -2 AMNH 134 Tylosaurus nepaeolicus Dentary Tip 16 26 39 28 39 28 65 18 65 18 99 20 99 20 131 19 AMNH 134 Tylosaurus nepaeolicus Dentary Socket 21 -2 44 -4 44 -4 69 -8 69 -8 106 -10 106 -10 135 -11 AMNH 134 Tylosaurus nepaeolicus Dentary Tip 131 19 158 18 158 18 190 21 190 21 219 21 219 21 249 22 AMNH 134 Tylosaurus nepaeolicus Dentary Socket 135 -11 163 -9 163 -9 196 -10 196 -10 228 -11 228 -11 255 -9 AMNH 134 Tylosaurus nepaeolicus Dentary Tip 249 22 281 20 281 20 304 21 304 21 329 19 329 19 350 18 AMNH 134 Tylosaurus nepaeolicus Dentary Socket 255 -9 285 -5 285 -5 308 -4 308 -4 333 -2 333 -2 354 0 YPM-P4 4132 unidentifed Dentary Tip 65 25 97 28 165 27 191 22 YPM-P4 4132 unidentifed Dentary Socket 64 0 99 0 153 0 193 0 YPM-PU 17249 Clidastes liodontus Maxilla Tip 15 -12 24 -13 24 -13 43 -16 YPM-PU 17249 Clidastes liodontus Maxilla Socket 15 1 27 2 27 2 46 1

109

Specimen Species Jaw Bone Point Coordinate Set Coordinate Set Coordinate Set Coordinate Set AMNH 1593 Clidastes propython Maxilla Tip -3 -26 18 -26 18 -26 44 -14 44 -14 57 -26 57 -26 78 -7 AMNH 1593 Clidastes propython Maxilla Socket 0 0 21 0 21 0 46 -2 46 -2 61 -2 61 -2 81 -2 AMNH 1486 Clidastes tortor Maxilla Tip -2 -12 7 -12 7 -12 34 -17 34 -17 50 -19 50 -19 74 -21 AMNH 1486 Clidastes tortor Maxilla Socket 0 0 15 0 15 0 38 0 38 0 56 0 56 0 77 0 AMNH 505 Platecarpus coryphaeus Maxilla Tip 2 -31 26 -30 AMNH 505 Platecarpus coryphaeus Maxilla Socket 0 0 26 1 AMNH 1550 Platecarpus ictericus Maxilla Tip 215 -38 243 -38 AMNH 1550 Platecarpus ictericus Maxilla Socket 221 0 249 0 AMNH 1820 Platecarpus ictericus Maxilla Tip 61 -29 85 -31 147 -30 173 -29 173 -29 195 -30 -1 -21 20 -22 AMNH 1820 Platecarpus ictericus Maxilla Socket 65 3 89 3 161 2 182 1 182 1 203 0 0 0 22 3 AMNH 1820 Platecarpus ictericus Maxilla Tip 129 -29 153 -32 153 -32 177 -32 177 -32 193 -33 190 -29 213 -28 AMNH 1820 Platecarpus ictericus Maxilla Socket 140 4 164 3 164 3 186 1 186 1 207 0 202 0 225 0 AMNH 14788 Platecarpus sp. Maxilla Tip 2 -22 31 -25 82 -35 112 -35 112 -35 130 -37 130 -37 157 -35 AMNH 14788 Platecarpus sp. Maxilla Socket 0 0 18 0 90 -1 113 0 113 0 136 0 136 0 158 0 AMNH 14788 Platecarpus sp. Maxilla Tip 157 -35 180 -35 41 -34 68 -32 AMNH 14788 Platecarpus sp. Maxilla Socket 158 0 177 0 47 1 70 2 KUM 85586 Platecarpus sp. Maxilla Tip 2 -9 3 -9 3 -9 20 -14 20 -14 34 -15 KUM 85587 Platecarpus sp. Maxilla Socket 0 0 9 0 9 0 20 4 20 4 39 4 YPM 40436 Platecarpus sp. Maxilla Tip 56 -24 84 -27 223 -31 240 -28 YPM 40436 Platecarpus sp. Maxilla Socket 62 0 86 0 227 2 247 0 YPM 40439 Platecarpus sp. Maxilla Tip 49 -10 64 -28 YPM 40439 Platecarpus sp. Maxilla Socket 49 -3 67 0 YPM 40550 Platecarpus sp. Maxilla Tip -1 -15 13 -20 42 -24 62 -28 YPM 40550 Platecarpus sp. Maxilla Socket 0 0 11 1 45 3 63 3 YPM 40613 Platecarpus sp. Maxilla Tip 30 -25 48 -28 92 -32 113 -33 113 -33 135 -35 YPM 40613 Platecarpus sp. Maxilla Socket 31 -1 53 0 94 1 117 0 117 0 141 0

110

Specimen Species Jaw Bone Point Coordinate Set Coordinate Set Coordinate Set Coordinate Set YPM 3974 Tylosaurus nepaeolicus Maxilla Tip 133 -32 160 -31 160 -31 186 -31 186 -31 214 -29 214 -29 234 -26 YPM 3974 Tylosaurus nepaeolicus Maxilla Socket 134 0 162 -1 162 -1 189 0 189 0 213 0 213 0 234 0 YPM 3974 Tylosaurus nepaeolicus Maxilla Tip 77 -29 99 -31 99 -31 125 -32 YPM 3974 Tylosaurus nepaeolicus Maxilla Socket 80 0 107 0 107 0 132 0 AMNH 4909 Tylosaurus proriger Maxilla Tip 75 -24 103 -25 152 -26 188 -25 AMNH 4909 Tylosaurus proriger Maxilla Socket 79 2 109 3 163 1 189 0 YPM 2062 unidentified Maxilla Tip 0 31 25 10 25 10 22 31 22 31 83 53 YPM 2062 unidentified Maxilla Socket 0 0 30 0 30 0 47 0 47 0 83 -3 YPM-P4 4134 unidentified Maxilla Tip -5 -24 12 -25 12 -25 28 -27 103 -29 120 -29 YPM-P4 4135 unidentified Maxilla Socket 0 0 15 0 15 0 34 2 107 2 124 1 YPM 24931 Platecarpus ictericus Premaxilla Tip 17 -29 32 -24 YPM 24931 Platecarpus ictericus Premaxilla Socket 19 2 33 0

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Table A3: Original coordinates and Bookstein coordinates for all tooth pairs in the dentary. Each string of eight numbers represents a tooth pair.

The first four numbers are the x- and y- coordinates of the base of the first tooth followed by the x- and y- coordinates of the base of the second tooth and the following four numbers are the x- and y- coordinates of the tip of the first tooth followed by the x- and y- coordinates of the tip of the second tooth.

Genera Original Coordinates Bookstein Coordinates Clidastes 31 -3 51 -4 30 13 49 12 0 0 1 0 -0.0898 0.7955 0.8603 0.7930 (6 sets) 113 -4 130 -2 110 14 127 13 0 0 1 0 -0.0512 1.0649 0.9283 0.8908 136 -2 154 -2 134 18 152 20 0 0 1 0 -0.1111 1.1111 0.8889 1.2222 154 -2 171 -1 152 20 169 19 0 0 1 0 -0.0414 1.2966 0.9517 1.1793 170 0 187 0 170 20 187 21 0 0 1 0 0.0000 1.1765 1.0000 1.2353 187 0 203 0 187 21 204 19 0 0 1 0 0.0000 1.3125 1.0625 1.1875 Platecarpus 24 0 50 -1 26 30 51 30 0 0 1 0 0.0325 1.1551 0.9926 1.1920 (35 sets) 50 -1 73 -1 51 30 73 28 0 0 1 0 0.0435 1.3478 1.0000 1.2609 73 -1 99 1 73 28 99 30 0 0 1 0 0.0853 1.1088 1.0853 1.1088 218 0 235 0 225 26 238 26 0 0 1 0 0.4118 1.5294 1.1765 1.5294 0 0 16 -2 -1 20 15 22 0 0 1 0 -0.2154 1.2231 0.7538 1.4692 16 -2 34 -3 15 22 33 23 0 0 1 0 -0.1292 1.3262 0.8646 1.4369 34 -3 56 -5 33 23 53 23 0 0 1 0 -0.1516 1.1680 0.7500 1.2500 56 -5 76 -5 53 23 71 23 0 0 1 0 -0.1500 1.4000 0.7500 1.4000 76 -5 97 -5 71 23 93 22 0 0 1 0 -0.2381 1.3333 0.8095 1.2857 133 -3 151 -2 126 25 144 26 0 0 1 0 -0.3015 1.5723 0.6985 1.5723 151 -2 168 0 144 26 162 27 0 0 1 0 -0.2150 1.6724 0.8362 1.6075 0 0 13 0 1 15 13 17 0 0 1 0 0.0769 1.1539 1.0000 1.3077 13 0 32 0 13 17 31 17 0 0 1 0 0.0000 0.8947 0.9474 0.8947 32 0 54 0 31 17 51 22 0 0 1 0 -0.0455 0.7727 0.8636 1.0000 0 0 22 -2 0 25 22 24 0 0 1 0 -0.1025 1.1271 0.8934 1.1721

112

Genera Original Coordinates Bookstein Coordinates 0 0 18 -1 1 21 15 23 0 0 1 0 -0.0092 1.1662 0.7600 1.3200 18 -1 34 -1 15 23 32 24 0 0 1 0 -0.1875 1.5000 0.8750 1.5625 34 -1 54 0 32 24 52 25 0 0 1 0 -0.0374 1.2519 0.9626 1.2519 45 0 68 0 47 27 69 25 0 0 1 0 0.0870 1.1739 1.0435 1.0870 60 0 79 0 58 31 78 29 0 0 1 0 -0.1053 1.6316 0.9474 1.5263 114 1 130 0 112 30 131 27 0 0 1 0 -0.2374 1.7977 0.9572 1.6848 44 -4 69 -5 37 21 63 22 0 0 1 0 -0.3195 0.9872 0.7173 1.0687 69 -5 87 -6 63 22 81 24 0 0 1 0 -0.4154 1.4769 0.5754 1.6431 87 -6 114 -6 81 24 106 25 0 0 1 0 -0.2222 1.1111 0.7037 1.1482 0 0 24 -1 -4 21 21 24 0 0 1 0 -0.2028 0.8666 0.8319 1.0347 24 -1 46 -2 21 24 41 25 0 0 1 0 -0.1876 1.1278 0.7175 1.2144 238 0 254 0 240 33 257 28 0 0 1 0 0.1250 2.0625 1.1875 1.7500 0 0 21 -2 -2 21 25 18 0 0 1 0 -0.1888 0.9820 1.0989 0.9618 21 -2 42 -3 25 18 40 28 0 0 1 0 0.1448 0.9593 0.8348 1.4683 42 -3 69 -4 40 28 69 27 0 0 1 0 -0.1164 1.1438 0.9575 1.1466 146 -3 171 -2 143 28 170 29 0 0 1 0 -0.0703 1.2428 1.0096 1.2396 171 -2 193 -1 170 29 195 30 0 0 1 0 0.0186 1.4083 1.1546 1.4021 193 -1 217 0 195 30 218 29 0 0 1 0 0.1369 1.2860 1.0919 1.2045 217 0 233 0 218 29 242 30 0 0 1 0 0.0625 1.8125 1.5625 1.8750 96 -3 117 -5 92 21 116 22 0 0 1 0 -0.2966 1.1146 0.8315 1.2697 Tylosaurus 0 0 23 -1 -4 29 19 29 0 0 1 0 -0.2283 1.2509 0.7698 1.2943 (21 sets) 23 -1 52 -7 19 29 46 21 0 0 1 0 -0.3375 0.9647 0.6100 0.8848 52 -7 84 -11 46 21 81 18 0 0 1 0 -0.2923 0.8385 0.7962 0.8808 84 -11 114 -12 81 18 109 20 0 0 1 0 -0.1321 0.9623 0.7980 1.0599 114 -12 142 -12 109 20 136 19 0 0 1 0 -0.1786 1.1429 0.7857 1.1071 142 -12 178 -10 136 19 172 20 0 0 1 0 -0.1185 0.8677 0.8800 0.8400

113

Genera Original Coordinates Bookstein Coordinates Tylosaurus 236 -8 264 -5 231 22 256 18 0 0 1 0 -0.0631 1.0782 0.8045 0.8424 264 -5 290 -4 256 18 286 24 0 0 1 0 -0.2733 0.8951 0.8877 1.0812 0 0 21 -2 -6 20 16 26 0 0 1 0 -0.3730 0.9169 0.6382 1.2989 21 -2 44 -4 16 26 39 28 0 0 1 0 -0.3208 1.1895 0.6642 1.3621 44 -4 69 -8 39 28 65 18 0 0 1 0 -0.3947 1.2169 0.6817 0.9891 69 -8 106 -10 65 18 99 20 0 0 1 0 -0.1457 0.6948 0.7677 0.7983 106 -10 135 -11 99 20 131 19 0 0 1 0 -0.2767 1.0249 0.8266 1.0285 135 -11 163 -9 131 19 158 18 0 0 1 0 -0.0660 1.0761 0.8909 0.9721 163 -9 196 -10 158 18 190 21 0 0 1 0 -0.1761 0.8128 0.7899 0.9330 196 -10 228 -11 190 21 219 21 0 0 1 0 -0.2176 0.9620 0.6878 0.9902 228 -11 255 -9 219 21 249 22 0 0 1 0 -0.2442 1.2033 0.8636 1.1583 255 -9 285 -5 249 22 281 20 0 0 1 0 -0.0611 1.0415 0.9782 0.8362 285 -5 308 -4 281 20 304 21 0 0 1 0 -0.1264 1.0925 0.8736 1.0925 308 -4 333 -2 304 21 329 19 0 0 1 0 -0.0795 1.0064 0.9078 0.8474 333 -2 354 0 329 19 350 18 0 0 1 0 -0.0944 1.0090 0.8921 0.8674 Unidentified 64 0 99 0 65 25 97 28 0 0 1 0 0.0286 0.7143 0.9429 0.8000 (2 sets) 153 0 193 0 165 27 191 22 0 0 1 0 0.3000 0.6750 0.9500 0.5500

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Table A4: Original coordinates and Bookstein coordinates for tooth pairs in the maxilla and premaxilla. Each string of eight numbers represents a tooth pair. The first four numbers are the x- and y- coordinates of the base of the first tooth followed by the x- and y- coordinates of the base of the second tooth and the following four numbers are the x- and y- coordinates of the tip of the first tooth followed by the x- and y- coordinates of the tip of the second tooth.

Genera Original Coordinates Bookstein Coordinates Clidastes 15 1 27 2 15 -12 24 -13 0 0 1 0 -0.0897 -1.0759 0.6483 -1.2207 (10 sets) 27 2 46 1 24 -13 43 -16 0 0 1 0 -0.1160 -0.7956 0.8895 -0.9006 0 0 21 0 -3 -26 18 -26 0 0 1 0 -0.1429 -1.2381 0.8571 -1.2381 21 0 46 -2 18 -26 44 -14 0 0 1 0 -0.0366 -1.0429 0.9587 -0.4833 46 -2 61 -2 44 -14 57 -26 0 0 1 0 -0.1333 -0.8000 0.7333 -1.6000 61 -2 81 -2 57 -26 78 -7 0 0 1 0 -0.2000 -1.2000 0.8500 -0.2500 0 0 15 0 -2 -12 7 -12 0 0 1 0 -0.1333 -0.8000 0.4667 -0.8000 15 0 38 0 7 -12 34 -17 0 0 1 0 -0.3478 -0.5217 0.8261 -0.7391 38 0 56 0 34 -17 50 -19 0 0 1 0 -0.2222 -0.9444 0.6667 -1.0556 56 0 77 0 50 -19 74 -21 0 0 1 0 -0.2857 -0.9048 0.8571 -1.0000 Platecarpus 0 0 26 1 2 -31 26 -30 0 0 1 0 0.0310 -1.1935 0.9542 -1.1906 (27 sets) 202 0 225 0 190 -29 213 -28 0 0 1 0 -0.5217 -1.2609 0.4783 -1.2174 65 3 89 3 61 -29 85 -31 0 0 1 0 -0.1667 -1.3333 0.8333 -1.4167 161 2 182 1 147 -30 173 -29 0 0 1 0 -0.5928 -1.5520 0.6403 -1.4457 182 1 203 0 173 -29 195 -30 0 0 1 0 -0.3597 -1.4457 0.6878 -1.4434 0 0 22 3 -1 -21 20 -22 0 0 1 0 -0.1724 -0.9310 0.7586 -1.1035 140 4 164 3 129 -29 153 -32 0 0 1 0 -0.4003 -1.3917 0.6031 -1.4749 164 3 186 1 153 -32 177 -32 0 0 1 0 -0.3525 -1.6230 0.7295 -1.5246 186 1 207 0 177 -32 193 -33 0 0 1 0 -0.3529 -1.5882 0.4095 -1.5996 221 0 249 0 215 -38 243 -38 0 0 1 0 -0.2143 -1.3571 0.7857 -1.3571 0 0 9 0 2 -9 3 -9 0 0 1 0 0.2222 -1.0000 0.3333 -1.0000 115

Genera Original Coordinates Bookstein Coordinates Platecarpus 9 0 20 4 3 -9 20 -14 0 0 1 0 -0.7445 -0.5474 0.4745 -1.4453 20 4 39 4 20 -14 34 -15 0 0 1 0 0.0000 -0.9474 0.7368 -1.0000 49 -3 67 0 49 -10 64 -28 0 0 1 0 -0.0631 -0.3784 0.5856 -1.4865 62 0 86 0 56 -24 84 -27 0 0 1 0 -0.2500 -1.0000 0.9167 -1.1250 227 2 247 0 223 -31 240 -28 0 0 1 0 -0.0347 -1.6535 0.7921 -1.4208 31 -1 53 0 30 -25 48 -28 0 0 1 0 -0.0948 -1.0866 0.7155 -1.2598 94 1 117 0 92 -32 113 -33 0 0 1 0 -0.0245 -1.4359 0.8887 -1.4396 117 0 141 0 113 -33 135 -35 0 0 1 0 -0.1667 -1.3750 0.7500 -1.4583 0 0 11 1 -1 -15 13 -20 0 0 1 0 -0.2131 -1.3443 1.0082 -1.9098 45 3 63 3 42 -24 62 -28 0 0 1 0 -0.1667 -1.5000 0.9444 -1.7222 0 0 18 0 2 -22 31 -25 0 0 1 0 0.1111 -1.2222 1.7222 -1.3889 90 -1 113 0 82 -35 112 -35 0 0 1 0 -0.4113 -1.4604 0.8906 -1.5170 113 0 136 0 112 -35 130 -37 0 0 1 0 -0.0435 -1.5217 0.7391 -1.6087 136 0 158 0 130 -37 157 -35 0 0 1 0 -0.2727 -1.6818 0.9545 -1.5909 158 0 177 0 157 -35 180 -35 0 0 1 0 -0.0526 -1.8421 1.1579 -1.8421 47 1 70 2 41 -34 68 -32 0 0 1 0 -0.3264 -1.5076 0.8491 -1.4717 Platecarpus (Premaxilla) 19 2 33 0 17 -29 32 -24 0 0 1 0 0.1700 -2.1900 1.1700 -1.6900 Tylosaurus 134 0 162 -1 133 -32 160 -31 0 0 1 0 0.0051 -1.1427 0.9669 -1.0726 (8 sets) 162 -1 189 0 160 -31 186 -31 0 0 1 0 -0.1151 -1.1069 0.8466 -1.1425 189 0 213 0 186 -31 214 -29 0 0 1 0 -0.1250 -1.2917 1.0417 -1.2083 213 0 234 0 214 -29 234 -26 0 0 1 0 0.0476 -1.3810 1.0000 -1.2381 80 0 107 0 77 -29 99 -31 0 0 1 0 -0.1111 -1.0741 0.7037 -1.1482 107 0 132 0 99 -31 125 -32 0 0 1 0 -0.3200 -1.2400 0.7200 -1.2800 79 2 109 3 75 -24 103 -25 0 0 1 0 -0.1620 -0.8613 0.7691 -0.9256 163 1 189 0 152 -26 188 -25 0 0 1 0 -0.3826 -1.0532 0.9985 -0.9616 Unidentified 0 0 15 0 -5 -24 12 -25 0 0 1 0 -0.3333 -1.6000 0.8000 -1.6667 (5 sets) 15 0 34 2 12 -25 28 -27 0 0 1 0 -0.2932 -1.2849 0.5288 -1.4767

116

Genera Original Coordinates Bookstein Coordinates Unidentified 107 2 124 1 103 -29 120 -29 0 0 1 0 -0.1276 -1.8310 0.8690 -1.7724 0 0 47 0 0 31 22 31 0 0 1 0 0.0000 0.6596 0.4681 0.6596 47 0 83 -3 22 31 83 53 0 0 1 0 -0.7609 0.7977 0.8713 1.5448

117

Table A5: Calculations of the tooth tips in tooth pairs. BC1 and BC2 give the x-coordinate (in Bookstein coordinates) for the first and second, respectively, teeth in the pairs. This information was taken directly from Tables A3 and A4. BC2 – 1 is the x-coordinate (in Bookstein coordinates) of the second tooth minus one. BC2 – BC1 is the distance between the two teeth along the x-axis.

Dentary Maxilla Genus BC1 BC2 BC2 - 1 BC2 - BC1 Genus BC1 BC2 BC2 - 1 BC2 - BC1 Clidastes -0.0898 0.8603 -0.1397 0.9501 Clidastes -0.0897 0.6483 -0.3517 0.7379 Clidastes -0.0512 0.9283 -0.0717 0.9795 Clidastes -0.1160 0.8895 -0.1105 1.0055 Clidastes -0.1111 0.8889 -0.1111 1.0000 Clidastes -0.1429 0.8571 -0.1429 1.0000 Clidastes -0.0414 0.9517 -0.0483 0.9931 Clidastes -0.0366 0.9587 -0.0413 0.9952 Clidastes 0.0000 1.0000 0.0000 1.0000 Clidastes -0.1333 0.7333 -0.2667 0.8667 Clidastes 0.0000 1.0625 0.0625 1.0625 Clidastes -0.2000 0.8500 -0.1500 1.0500 Platecarpus 0.0325 0.9926 -0.0074 0.9601 Clidastes -0.1333 0.4667 -0.5333 0.6000 Platecarpus 0.0435 1.0000 0.0000 0.9565 Clidastes -0.3478 0.8261 -0.1739 1.1739 Platecarpus 0.0853 1.0853 0.0853 1.0000 Clidastes -0.2222 0.6667 -0.3333 0.8889 Platecarpus 0.4118 1.1765 0.1765 0.7647 Clidastes -0.2857 0.8571 -0.1429 1.1429 Platecarpus -0.2154 0.7538 -0.2462 0.9692 Platecarpus 0.0310 0.9542 -0.0458 0.9232 Platecarpus -0.1292 0.8646 -0.1354 0.9938 Platecarpus -0.5217 0.4783 -0.5217 1.0000 Platecarpus -0.1516 0.7500 -0.2500 0.9016 Platecarpus -0.1667 0.8333 -0.1667 1.0000 Platecarpus -0.1500 0.7500 -0.2500 0.9000 Platecarpus -0.5928 0.6403 -0.3597 1.2330 Platecarpus -0.2381 0.8095 -0.1905 1.0476 Platecarpus -0.3597 0.6878 -0.3122 1.0475 Platecarpus -0.3015 0.6985 -0.3015 1.0000 Platecarpus -0.1724 0.7586 -0.2414 0.9310 Platecarpus -0.2150 0.8362 -0.1638 1.0512 Platecarpus -0.4003 0.6031 -0.3969 1.0035 Platecarpus 0.0769 1.0000 0.0000 0.9231 Platecarpus -0.3525 0.7295 -0.2705 1.0820 Platecarpus 0.0000 0.9474 -0.0526 0.9474 Platecarpus -0.3529 0.4095 -0.5905 0.7624 Platecarpus -0.0455 0.8636 -0.1364 0.9091 Platecarpus -0.2143 0.7857 -0.2143 1.0000 Platecarpus -0.1025 0.8934 -0.1066 0.9959 Platecarpus 0.2222 0.3333 -0.6667 0.1111 Platecarpus -0.0092 0.7600 -0.2400 0.7692 Platecarpus -0.7445 0.474 -0.5255 1.2190 118

Dentary Maxilla BC2 - BC2 - Genus BC1 BC2 BC2 - 1 BC1 Genus BC1 BC2 BC2 - 1 BC1 Platecarpus -0.1875 0.8750 -0.1250 1.0625 Platecarpus 0.0000 0.7368 -0.2632 0.7368 Platecarpus -0.0374 0.9626 -0.0374 1.0000 Platecarpus -0.0631 0.5856 -0.4144 0.6486 Platecarpus 0.0870 1.0435 0.0435 0.9565 Platecarpus -0.2500 0.9167 -0.0833 1.1667 Platecarpus -0.1053 0.9474 -0.0526 1.0526 Platecarpus -0.0347 0.7921 -0.2079 0.8267 Platecarpus -0.2374 0.9572 -0.0428 1.1946 Platecarpus -0.0948 0.7155 -0.2845 0.8103 Platecarpus -0.3195 0.7173 -0.2827 1.0367 Platecarpus -0.0245 0.8887 -0.1113 0.9132 Platecarpus -0.4154 0.5754 -0.4246 0.9908 Platecarpus -0.1667 0.7500 -0.2500 0.9167 Platecarpus -0.2222 0.7037 -0.2963 0.9259 Platecarpus -0.2131 1.0082 0.0082 1.2213 Platecarpus -0.2028 0.8319 -0.1681 1.0347 Platecarpus -0.1667 0.9444 -0.0556 1.1111 Platecarpus -0.1876 0.7175 -0.2825 0.9052 Platecarpus 0.1111 1.7222 0.7222 1.6111 Platecarpus 0.1250 1.1875 0.1875 1.0625 Platecarpus -0.4113 0.8906 -0.1094 1.3019 Platecarpus -0.1888 1.0989 0.0989 1.2876 Platecarpus -0.0435 0.7391 -0.2609 0.7826 Platecarpus 0.1448 0.8348 -0.1652 0.6900 Platecarpus -0.2727 0.9545 -0.0455 1.2273 Platecarpus -0.1164 0.9575 -0.0425 1.0740 Platecarpus -0.0526 1.1579 0.1579 1.2105 Platecarpus -0.0703 1.0096 0.0096 1.0799 Platecarpus -0.3264 0.8491 -0.1509 1.1755 Platecarpus 0.0186 1.1546 0.1546 1.1361 Platecarpus 0.1700 1.1700 0.1700 1.0000 Platecarpus 0.1369 1.0919 0.0919 0.9549 Tylosaurus 0.0051 0.9669 -0.0331 0.9618 Platecarpus 0.0625 1.5625 0.5625 1.5000 Tylosaurus -0.1151 0.8466 -0.1534 0.9616 Platecarpus -0.2966 0.8315 -0.1685 1.1281 Tylosaurus -0.1250 1.0417 0.0417 1.1667 Tylosaurus -0.2283 0.7698 -0.2302 0.9981 Tylosaurus 0.0476 1.0000 0.0000 0.9524 Tylosaurus -0.3375 0.6100 -0.3900 0.9475 Tylosaurus -0.1111 0.7037 -0.2963 0.8148 Tylosaurus -0.2923 0.7962 -0.2038 1.0885 Tylosaurus -0.3200 0.7200 -0.2800 1.0400 Tylosaurus -0.1321 0.7980 -0.2020 0.9301 Tylosaurus -0.1620 0.7691 -0.2309 0.9312 Tylosaurus -0.1786 0.7857 -0.2143 0.9643 Tylosaurus -0.3826 0.9985 -0.0015 1.3811

119

Dentary Maxillia Genus BC1 BC2 BC2 - 1 BC2 - BC1 Genus BC1 BC2 BC2 - 1 BC2 - BC1 Tylosaurus -0.1185 0.8800 -0.1200 0.9985 Unidentified -0.3333 0.8000 -0.2000 1.1333 Tylosaurus -0.0631 0.8045 -0.1955 0.8676 Unidentified -0.2932 0.5288 -0.4712 0.8219 Tylosaurus -0.2733 0.8877 -0.1123 1.1610 Unidentified -0.1276 0.8690 -0.1310 0.9966 Tylosaurus -0.3730 0.6382 -0.3618 1.0112 Unidentified 0.0000 0.4681 -0.5319 0.4681 Tylosaurus -0.3208 0.6642 -0.3358 0.9850 Unidentified -0.7609 0.8713 -0.1287 1.6322 Tylosaurus -0.3947 0.6817 -0.3183 1.0764 Tylosaurus -0.1457 0.7677 -0.2323 0.9133 Tylosaurus -0.2767 0.8266 -0.1734 1.1033 Tylosaurus -0.0660 0.8909 -0.1091 0.9569 Tylosaurus -0.1761 0.7899 -0.2101 0.9661 Tylosaurus -0.2176 0.6878 -0.3122 0.9054 Tylosaurus -0.2442 0.8636 -0.1364 1.1078 Tylosaurus -0.0611 0.9782 -0.0218 1.0393 Tylosaurus -0.1264 0.8736 -0.1264 1.0000 Tylosaurus -0.0795 0.9078 -0.0922 0.9873 Tylosaurus -0.0944 0.8921 -0.1079 0.9865 Unidentified 0.0286 0.9429 -0.0571 0.9143 Unidentified 0.3000 0.9500 -0.0500 0.6500

120

Appendix B: Description of Crushed Nautilus Shells

In all of these trials, the body chamber of the Nautilus shell was packed with modeling clay. The same amount of clay was used in each specimen, except for specimen 3, which had no clay in it, and specimen 20, where a little bit more clay was added to fill the shell because the shell was a little larger than the others. On average, the clay was level with the opening of the body chamber, though in smaller shells, the clay extended beyond the aperture a little bit while in larger shells, the clay didn’t quite make it to the edge of the aperture.

In the following descriptions of each of the 20 trials, a hole is a mark that passes entirely through the shell wall. An indentation is a mark that is visible but has not broken through the shell.

Figure B1 shows simple sketches of the different orientations of the skull used in this experiment.

For specimens 1-3, the skull was at rest, meaning no cranial kinesis was simulated: the lower jaws were directly below the upper jaws and there was no mandibular flexing.

1. Orientation of shell: The shell was centered between the left and right sides of the jaws, the body chamber was on the left side, the aperture was directed to the right and forward. (Compare to trials 4,

6, and 18.)

Results (Figure B2): Left tooth rows (top and bottom) broke off body chamber. There were two holes on the top, right side of the shell and one hole and one indentation on the bottom, right side of the shell.

2. Orientation of shell: The shell was centered between the left and right sides of the jaws, the body chamber was on the right side, the aperture was directed to the left and forward. (Compare to trials 5 and 7.)

Results (Figure B3): Right tooth rows (top and bottom) broke off body chamber. There were two holes and one indentation on the top left side of the shell and two holes and two indentations on the bottom left side of the shell. 121

3. Orientation of shell: The shell was centered between the left and right sides of the jaws, the body chamber was on the left side, the aperture was directed to the right and forward. There was no clay in the body chamber of the shell. The phragmocone was resting on the lower, right tooth row. (Compare to trials 4, 6 and 18.)

Results (Figure B4): Top left tooth row broke the body chamber. There were one hole and one deep indentation near the umbilicus on the top right and two holes and one indentation on the bottom right.

The orientation and set up of the jaws had not been checked or adjusted to this point. After specimen three was crushed, the dentary of the lower jaw was found to have deflected up to its maximum extent and twisted clockwise. This shift likely occurred over the crushing of the first three specimens. After this point, the jaws were examined after each crushing and re-adjusted if it was necessary.

For specimens 4-5, the lower jaw was retracted 18mm, and there was no mandibular flexing.

4. Orientation of shell: The shell was centered between the left and right sides of the jaws, the body chamber was on the left side. The aperture was directed to the right and forwards. (Compare to trials

1, 3, 6, 18, and 20.)

Results (Figure B5): Left tooth rows (top and bottom) crushed the body chamber. There were two holes and one indentation on the top right side and three holes on the bottom right.

5. Orientation of shell: The shell was centered between the left and right sides of the jaws, the body chamber was on the right side. The aperture was directed forwards and to the left. The phragmocone was resting on the teeth in the lower jaw. The shell had two pre-existing cracks on the midline at the tip of the body chamber. These cracks did not seem to affect the crushing of the shell except that the body chamber failed at the cracks first. Many of the other shells also cracked along the midline of the body chamber, however, so the effect of the cracks was likely minimal. (Compare to trials 2, 7, 11, and 19.) 122

Results (Figure B6): Right tooth rows (top and bottom) crushed the body chamber. The phragmocone broke along the left tooth row behind the first septum. There were two holes and one indentation on the top left side and two holes and one deep indentation on the bottom left side.

For specimens 6-7, the lower jaw was protracted 14 mm, and there was no mandibular flexing.

6. Orientation of shell: The shell was centered between the left and right sides of the jaws, the body chamber was to the left. The aperture was directed to the right and forwards. The shell was situated towards the anterior of the jaws. (Compare to trials 1, 3, 4, 18, and 20.)

Results (Figure B7): The upper jaws sheared to the left during the crushing. The left tooth rows

(top and bottom) crushed the body chamber. There were one hole and two indentations on the top right and two holes on the bottom right.

7. Orientation of shell: The shell was centered between the left and right sides of the jaws, the body chamber was to the right. The aperture was directed forwards and to the left. The shell was situated towards the anterior of the jaws. There was a large preexisting hole on the back of the phragmocone but it did not appear to affect the way the shell crushed as the hole remained the same size after crushing and there were no new cracks coming from it. (Compare to trials 2, 5, 11, and 19.)

Results (Figure B8): Right tooth rows (top and bottom) crushed the body chamber. There were two holes, one indentation and one chip on the edge of the body chamber on the top left and two holes and one indentation on the bottom left.

For specimens 8-10, the skull was set to no cranial kinesis.

8. Orientation of shell: The phragmocone was centered between the two sides of the jaws and the body chamber was on the left. The aperture was directed to the right.

Results (Figure B9): Left tooth rows (top and bottom) broke the shell behind the first septum.

There was one hole on the bottom right side, one hole on the top right side, and three holes on the top left side (the latter were on the body chamber). 123

9. Orientation of shell: The umbilicus was centered under the 9th tooth in the left side of the skull and the body chamber was on the right. The aperture was directed to the left. The phragmocone was lying on the teeth in the lower jaw.

Results (Figure B10): Partway through the crushing, it was observed that two teeth from the left dentary punctured the shell but at the same time, there was only one indentation on the top left side.

When the shell was fully crushed, the right tooth rows (top and bottom) had crushed the body chamber.

There were two holes on the top left and three holes on the bottom left. The 9th tooth never made it to the umbilicus (the umbilicus was too deep).

10. Orientation of shell: The umbilicus was centered on the 7th tooth in the right side of the skull and the body chamber was on the left. The aperture was directed to the right. The phragmocone was in contact with the lower tooth row.

Results (Figure B11): Partway through the crushing, it was observed that the 8th tooth in the right side of the skull began to puncture before the teeth from the right dentary did. When the shell was fully crushed, the left tooth rows (top and bottom) crushed the body chamber. There were two holes and one indentation on the top right and two holes and one indentation on the top right.

For specimens 11-15, the dentaries with the missing teeth were used.

For specimens 11-13, the skull was at rest.

11. Orientation of shell: The shell was centered between the left and right sides of the jaws, the body chamber was to the right. The aperture was directed to the left and forwards. The shell was situated towards the anterior of the jaws. (Compare to trials 2, 5, 7, and 19.)

Results (Figure B12): Right tooth rows (top and bottom) broke the body chamber. There were two holes and one scratch on the top left side and two holes on the bottom left. The first septum was cracked below the siphuncle. 124

12. Orientation of shell: The phragmocone was centered over the gap between the 9th and 11th teeth in the right dentary. The body chamber was to the left and the aperture was directed to the right.

Results (Figures B13 and B14): Partway through the crushing, the shell was removed, examined, and photographed. At this point, there were two indentations on the top right, one hole and two indentations on the top left, one hole and one indentation on the bottom right, and one hole and two indentations on the bottom left. The shell was then replaced and crushing continued. When the shell was fully crushed, the upper left tooth row crushed the body chamber. There was one hole and one indentation on the top right, three holes on the bottom right, and three holes on the bottom left.

13. Orientation of shell: The shell was centered between the two sides of the jaws. The body chamber was to the left and the phragmocone was over the gap between the 9th and 11th teeth in the right dentary. The aperture was directed forwards.

Results (Figure B15): Top left tooth row crushed the body chamber. There were three holes on the top right, two holes on the bottom right, and three holes along a crack on the bottom left.

For specimens 14-15, the lower jaw was retracted 18 mm, and there was no mandibular flexing.

14. Orientation of shell: The shell was centered between the two sides of the jaws. The body chamber was to the left, centered over the gap between the 3rd and 5th teeth in the left dentary. The aperture was directed forwards and to the right.

Results (Figures B16 and B17): Partway through the crushing, the shell was removed, examined, and photographed. The top left tooth row had crushed the body chamber. There was one hole on the top right, one hole on the bottom right, one hole and one indentation on the bottom left. The shell was then replaced and crushing continued. The top left tooth row continued to crush the shell. There were two holes and one indentation on the top right, one hole on the bottom right, and two holes and one indentation on the bottom left. 125

15. Orientation of shell: The shell was centered between the two sides of the jaws. The body chamber was to the left, centered over the gap between the 3rd and 5th teeth in the left dentary. The aperture was directed more forward than the previous specimen. The first septum of the shell was collapsed prior to crushing.

Results (Figure B18 and B19): Partway through the crushing, the shell was removed, examined, and photographed. The top left tooth row crushed the body chamber. There was a hole on the top right, a hole on the top left, one hole on the bottom left, and one hole on the bottom right. The shell was then replaced and crushing continued. As the shell was fully crushed, the left tooth rows (top and bottom) crushed the body chamber. There were two holes on the top right and two holes and one indentation on the bottom right.

For specimens 16-20, the dentaries with no missing teeth were used.

For specimens 16-18, the dentary was elevated to its maximum extent, and the lower jaws were directly under the upper jaws.

16. Orientation of shell: The shell was centered between the right and left jaws. The body chamber was on the right and the aperture was directed to the left. There was a large pre-existing hole on the back of the phragmocone. This hole did not appear to affect the way the shell was crushed as the hole was not expanded and no cracks originated from it.

Results (Figure B20): Right tooth rows (top and bottom) crushed the body chamber. There was one hole and one indentation on the top left and two holes and one indentation on bottom left.

17. Orientation of shell: The shell was centered between the right and left jaws. The shell was placed further back in the jaws. The body chamber was to the left and the aperture was directed forwards.

The phragmocone was resting on the teeth in the right dentary.

Results (Figure B21): The right tooth rows (top and bottom) broke the phragmocone behind the first septum. The top left tooth row crushed the body chamber. There was one hole on the bottom left. 126

18. Orientation of shell: The shell was centered between the right and left jaws. The shell was placed more forward in the jaws. The body chamber was on the left and the aperture was directed forwards and to the right. (Compare to trials 1, 3, 4, 6, and 20.)

Results (Figure B22): Top left tooth row crushed the body chamber. There was one hole on the top right, two holes on the bottom right, and one hole on the bottom left.

For specimens 19-20, the skull was set to no cranial kinesis.

19. Orientation of shell: The shell was centered between the right and left jaws. The shell was placed more forward in the jaws. The body chamber was on the right and the aperture was directed forwards and to the left. The phragmocone was resting on the teeth in the left dentary. There was only one tooth in the skull that was in contact with the body chamber. (Compare to trials 5, 7, and 11.)

Results (Figures B23 and B24): Partway through the crushing, the shell was removed, examined, and photographed. Top right tooth row cracked the body chamber. There was one hole on the top left, one indentation on the bottom left, and one hole on the bottom right. The shell was then replaced and the crushing continued. The top right tooth row had crushed the body chamber more. There were two holes on the top left, one hole and one indentation on the bottom left, and one hole and one indentation on the bottom right.

20. Orientation of shell: The shell was centered between the right and left jaws. The body chamber was on the left and the aperture was directed to the right and forwards. The phragmocone was resting on the right dentary. There were only two teeth in the skull that were in contact with the body chamber.

(Compare to trials 4, 6, and 18.)

Results (Figure B25): Partway through the crushing, the shell was removed and examined. The top left tooth row cracked the body chamber. There were five holes on the top left (these were along the crack in the body chamber), one hole on the top right, four holes on the bottom left, and one indentation on the bottom right. The shell was then replaced and crushing continued. Left tooth rows 127

(top and bottom) crushed the body chamber. There were five holes on the top left, two holes on the top right, two holes on the bottom right and two holes on the bottom left.

128

Figure B1: Orientations of skull used to crush shells. A. shows a skull at rest: the lower jaw is directly under the upper jaws and the mandible is not flexed. This orientation was used for trials 1-3, 8-13, and

19-20. B. shows a skull with the lower jaw retracted and the mandible is not flexed. This orientation was used for trials 4-5 and 14-15. C. shows a skull with the lower jaw protracted and the mandible is not flexed. This orientation was used for trials 6-7. D. shows a skull with the dentary elevated and the lower jaw is directly under the upper jaws. This orientation was used for trials 16-18.

129

Figure B2: Final results for specimen 1. A. shows the top of the specimen, B. shows the bottom. Scale bar is 2 cm.

Figure B3: Final results for specimen 2. A. shows the top of the specimen, B. shows the bottom. Scale bar is 2 cm. 130

Figure B4: Final results for specimen 3. Note that this specimen has no clay in its body chamber. A. shows the top of the specimen, B. shows the bottom. Scale bar is 2 cm.

131

Figure B5: Final results for specimen 4. A. shows the top of the specimen, B. shows the bottom. Scale bar is 2 cm.

132

Figure B6: Final results for specimen 5. A. shows the top of the specimen, B. shows the bottom. Scale bar is 2 cm.

133

Figure B7: Final results for specimen 6. A. shows the top of the specimen, B. shows the bottom.

Figure B8: Final results for specimen 7. A. shows the top of the specimen, B. shows the bottom. Scale bar is 2 cm.

134

Figure B9: Final results for specimen 8. A. shows the top of the specimen, B. shows the bottom. Scale bar is 2 cm.

135

Figure B10: Final results for specimen 9. A. shows the top of the specimen, B. shows the bottom. Scale bar is 2 cm.

136

Figure B11: Final results for specimen 10. A. shows the top of the specimen, B. shows the bottom. Scale bar is 2 cm.

137

Figure B12: Final results for specimen 11. A. shows the top of the specimen, B. shows the bottom. Scale bar is 2 cm.

Figure B13: Specimen 12 partway through crushing. A. shows the top of the specimen, B. shows the bottom. Scale bar is 2 cm. 138

Figure B14: Final results for specimen 12. A. shows the top of the specimen, B. shows the bottom. Scale bar is 2 cm.

139

Figure B15: Final results for specimen 13. A. shows the top of the specimen, B. shows the bottom. The clay was removed from this specimen in this picture. Scale bar is 2 cm.

Figure B16: Specimen 14 partway through crushing. A. shows the top of the specimen, B. shows the bottom. Scale bar is 2 cm. 140

Figure B17: Final results for specimen 14. A. shows the top of the specimen, B. shows the bottom. Scale bar is 2 cm.

141

Figure B18: Specimen 15 partway through crushing. A. shows the top of the specimen, B. shows the bottom. Scale bar is 2 cm.

Figure B19: Final results for specimen 15. A. shows the top of the specimen, B. shows the bottom. Scale bar is 2 cm.

142

Figure B20: Final results for specimen 16. A. shows the top of the specimen, B. shows the bottom. The clay was removed in this picture. Scale bar is 2 cm.

Figure B21: Final results for specimen 17. A. shows the top of the specimen, B. shows the bottom. Scale bar is 2 cm.

143

Figure B22: Final results for specimen 18. A. shows the top of the specimen, B. shows the bottom. Scale bar is 2 cm.

Figure B23: Specimen 19 partway through crushing. A. shows the top of the specimen, B. shows the bottom. Scale bar is 2 cm.

144

Figure B24: Final results for specimen 19. A. shows the top of the specimen, B. shows the bottom. Scale bar is 2 cm.

Figure B25: Final results for specimen 20. A. shows the top of the specimen, B. shows the bottom. Scale bar is 2 cm.