Basal Ichthyopterygian Remains from the Grippia Bonebed (Early Triassic) of Marmierfjellet, Spitsbergen

Home , Cartorhynchus, Grippia, Hupehsuchus, Ichthyopterygia, Ichthyosaurus, Omphalosaurus

Basal ichthyopterygian remains from the Grippia bonebed (Early Triassic) of Marmierfjellet, Spitsbergen

M.Sc. Thesis at the Department of Biosciences and

the Natural History Museum, University of Oslo

Ole Frederik Roaldset

Basal ichthyopterygian remains from the Grippia bonebed (Early Triassic)

of Marmierfjellet, Spitsbergen

Ole Frederik Roaldset

Master Thesis in Biosciences

Paleontology

Department of Biosciences

Natural History Museum

Faculty of Mathematics and Natural Sciences

UNIVERSITY OF OSLO

April 2017

III

Basal ichthyopterygian remains from the Grippia bonebed (Early Triassic) of Marmierfjellet, Spitsbergen

This work is published digitally by Digitale utgivelser ved UiO (DUO), and catalogued in BYBSYS

Print by Reprosentralen, University of Oslo

ACKNOWLEDGEMENTS

I am deeply grateful to have had the opportunity of joining the Spitsbergen Mesozoic Research Group, and to have enjoyed an amazing field season on Svalbard. For as long as I can remember I have wanted to be part of a paleontological excavation. To the unique backdrop of Flowerdalen, and with the pleasure of a fantastic expedition crew, the field experience ended up surpassing all expectations.

First and foremost, I would like to thank my main supervisor, Jørn H. Hurum, for letting me on to the Triassic project and for providing all the support one could wish for. I also want to thank my co-supervisor, Glenn-Peter Sætre, and all the participants of the 2015 field season: Bjørn Lund, Øyvind Enger, Stig Larsen, Lena Kristiansen, Lene Liebe Delsett, Achim Reisdorf, Christina Pokriefke Ekeheien, Aubrey J. Roberts, Victoria Engelschiøn Nash, Charlotte Sletten Bjorå, and Inghild Halvorsen Økland, as well as May-Liss Knudsen Funke, Janne Bratvold, and Hans Arne Nakrem.

Ole Frederik Oslo, April 2017

CONTENTS

ACKNOWLEDGEMENTS…………………………………………………………………V

1. INTRODUCTION………………………………………………………….……….……..0

1.1 The Early Triassic of Svalbard…………………………………………….……………..0

1.2 Basal Ichthyopterygia…………………………………………………………………....1

1.3 Historical review of Grippia……………………………………………………………..5

1.4 This study………………………………………………………………………………...6

1.5 Geological setting………………………………………………………………………...7

1.5.1 Svalbard in the Early Triassic……………………………………………………….….7

1.5.2 The Sassendalen group………………………………………………………....……….8

1.5.3 The Vikinghøgda formation…………………………………………………………….8

1.5.4 The Vendomdalen member……………………………………………………………10

1.5.5 The Grippia niveau……………………………………………………………………10

1.5.6 The Grippia bonebed…...…………………………………………………………….10

2. MATERIAL AND METHODS………………………………………………………….12

2.1 Excavation of the bonebed…………………………………………………………...…12

2.2 Material……………………………………………………………………………….....12

2.3 Field methods…………………………………………………………………………...12

2.4 Laboratory methods……………………………………………………………………..13

2.5 Measurements and descriptive terminology………………………………………….…13

3. DESCRIPTION…………………………………………………………………………..14

3.1 Grippia…………………………………………………………………………………..14

3.2 Cranial elements…………………………………………………………………………15

3.2.1 Mandibular elements………………………………………………………………….15

3.2.2 Maxillae……………………………………………………………………………….17

3.2.3 Palatine………………………………………………………………………………..18

3.2.4 Quadrate……………………………………………………………………...……….19

3.2.5 Basioccipital…………………………………………………………………………...21

3.3 Appendicular skeleton…………………………………………………………………...23

3.3.1 Humeri………………………………………………………………………………....23

3.3.2 Radii and ulnae………………………………………………………………….……..26

3.3.3 Paddle elements………………………………………………………………….….…26

3.4 Axial skeleton……………………………………………………………………...…….29

3.4.1 Costae……………………………………………………………………………...…..29

3.4.2 Cervical vertebrae…………………………………………………………..…………30

3.4.3 Dorsal vertebrae…………………………………………………………….…………31

3.4.4 Caudal vertebrae……………………………………………………………..………..32

3.4.5 Apophyses…………………………………………………………………….………33

4. DISCUSSION....…………………………………………………………………………36

4.1 Articulation of the quadrate…………….………………………………………………36

4.1.1 The ichthyopterygian quadrate……………………………………………………….36

4.1.2 Element PMO X (quadrate)………….…………………………………………….…36

4.1.3 Form and function of quadrates in terrestrial ancestors..……………………………..37

4.2 Outline of the body………………………………………..……………………………37

4.2.1 The basal ichthyopterygian bodyplan……………………..………………………….38

4.2.2 The dorsal vertebral centra of Grippia……………………………………………….38

4.2.3 The distal most caudal centra of Grippia…………………………………………….39

4.3 Size discrepancy and taxonomic certainty……………………………………………..40

5. CONCLUSION…………………………………………………………………………..41

VII

6. REFERENCES………………………………………………………………………..….42

7. APPENDICES……………………………………………………………………………50

7.1 Measurements of cervical centra………….…………………………………………….50

7.2 Measurements of dorsal centra………………………………………………………….52

7.3 Measurements of caudal centra…………………………………………………………65

VIII

1. INTRODUCTION 1.1 The Early Triassic of Svalbard

Life in the Early Triassic was to a great extent characterized by its preceding extinction event. The Permian Triassic Mass Extinction (PTME) is regarded as the most significant of all extinction events in the history of life on Earth (Erwin 1994, Benton 1995, Wignall and Twitchett 1996, Song et al. 2011, Scheyer et al. 2014, Roopnarine and Angielczyk 2015). It has been estimated to have reduced the number of terrestrial vertebrate taxa by 70 percent, and the number of marine faunal taxa by as much as 90 percent (Elewa 2008, Metcalfe and Isozaki 2009, Yin and Song 2013). The global tectonic activity that led to the forming of the supercontinent Pangea is believed to be the most likely underlying cause for the event (He et al. 2014, Yin and Song 2013). This resulted in the release of high amounts of gases into the atmosphere through volcanic activity, and ultimately to a warmer climate (Yin and Song 2013). The oceans circulation was affected by the increased temperature and eventually led to widespread anoxia in the seas (Sun et al. 2012). The aftermath of the devastating mass extinction opened up for rapid radiation together with novel exploitation of previously occupied niches by surviving taxa (Bardet et al. 2014, Ji et al. 2015). These major constitutional alterations of the biotas make investigation of the paleobiology in the Early Triassic a highly exciting subject. But due to occasional poor preservation and lack of diagnostic material in the fossil record it has proven challenging to map out the evolutionary history of certain clades (Motani et al. 2014, Ji et al. 2015).

Figure 1: Map of land masses in the early Triassic. The geographical positioning of Svalbard (study area) in the Boreal Sea is marked by a star. From Nash 2016 (modified from Sun et al. 2012).

The archipelago of Svalbard is located in the High Arctic of the Northeastern Atlantic Ocean. It consists of all land masses within the defined area from latitudes 74° - 81° north and longitudes 10° - 35° east, with Spitsbergen, Nordaustlandet and Edgeøya being the three largest islands. In the Early Triassic Svalbard was situated on the northern margin of the supercontinent Pangea, at approximately 42° north (Maxwell and Kear 2013). Here it formed a deep cold water shelf in a larger embayment called the Boreal Sea (Wignall et al. 1998, Dallmann et al. 2015). Fossilized remains of a variety of different marine taxa reside in the outcrops from the Early Triassic on several of the islands of Svalbard. Chondrichthyans and coelacanths, as well as marine tetrapods such as temnospondyls and ichtyopterygians are just some of these vertebrate taxa.

1.2 Basal Ichthyopterygia

Ichthyopterygia (Owen 1840) is a clade of marine reptiles that arose in the Early Triassic and came to have a cosmopolitan distribution throughout the Mesozoic (Bardet et al. 2014). The group stayed abundant on a world wide scale until the early Late Cretacious, the Cenomanian- Turonian boundary event (Fischer et al. 2014a). Secondarily aquatic, these pelagic diapsids have ecologically been compared to pinnipeds and especially cetaceans (Kelley and Pyenson

2015). Their physiological and anatomical adaptations to a life in the sea from a terrestrial tetrapod bauplan display an array of parallels to the evolutionary history of these groups (Kelley and Pyenson 2015). The definition of Ichthyopterygia by Motani (1999), modified by Ji et al. (2015), stating the last common ancestor of Ichthyosaurus communis Conybeare, 1822, Utatsusaurus hataii Shikama, Kamei & Murata, 1978 and Parvinatator wapitiensis Nicholls & Brinkman, 1995 is here followed. Remains of ichthyopterygians from the Triassic of Svalbard have been collected and described since the late 19th century (Nordenskiöld 1866, Hulke 1873, Dames 1895, Yakowlew 1903). To a much greater extent than the later derived forms, Early Triassic ichthyopterygians retained a variety of traits from their land dwelling ancestors (Massare & Callaway 1990, Motani et al. 2014). A shorter rostrum, a longer neck, more robust axial skeletons and notably more prevalent hind flippers and hip arrangements are often seen in the basal forms (Massare & Callaway 1990, Motani et al. 2014). These traits contribute to the idea of an anguilliform mode of locomotion rather than the thunniform which likely is the situation for the derived forms (Motani 1998). The dentition is another trait which underwent major morphological alterations throughout the Mesozoic. From a heterodont arrangement with teeth set in individual sockets to a dental groove in most derived forms (Massare & Callaway 1990). There is also a greater variation in different feeding mechanisms in the Early Triassic ichthyopterygians than in the derived forms (Motani et al. 2013). The basal members of the clade show evidence for ram feeding as well as suction feeding, and for a durophagous approach (Motani et al. 2013). The available material of basal ichthyopterygians is very limited and there is still great uncertainty as to the area the clade originated (Ji et al. 2015). Discoveries of ichthyopterygians from the Early Triassic have been done across the northern hemisphere with localities in Canada, Svalbard, China, Thailand and Japan (McGowan & Motani 2003).

Figure 2: Phylogeny of Ichthyopterygia. Note the distinction between the derived Ichthyosauria and the basal taxa. From Ji et al. 2015.

The enigmatic Omphalosaurus Merriam, 1906, is of highly uncertain ichtyopterygian affinity, and this is still subject for debate (Motani 2000, Maisch 2010). Remains of this genus have been dated to be as old as the earliest of ichtyhopterygians (Merriam 1906). Grippia longirostris Wiman, 1929, has traditionally played a crucial role. For close to a century the material Wiman described from Spitsbergen, Svalbard, represented the earliest ichthyopterygian material. The initial described material consisted of a semiarticulated skull and limb elements. It was collected as float material and therefore hard to trust in a strict stratigraphical sense. The Grippia Niveau was assigned to the Olenekian, Early Triassic based on information from palaeontologist E. Stensiö (Wiman 1929). Chaohusaurus geishanensis (Young and Dong 1972) was described on basis of a fragmented skeleton from Majianshan Limestone Formation, Yuanan County, China. This formation is of Anisian age, early Middle Triassic, and slightly younger than Grippia (Young and Dong 1972). In subsequent years several specimens from the genus Chensaurus have been reassigned to Chaohusaurus (Motani 1998). The exact phylogenetic positioning of the genus has been debated (Motani 1999). The same year Hupehsuchus nanchangensis Young 1972 was described, a skeleton from another Chinese locality in the Hubei province. This was of Olenekian age, Early

Triassic, but its ichthyopterygian affinity is deemed highly uncertain (Motani 1999). Hupesuchus is exclusively known from two counties in the Hubei province (Chen et al. 2014). The genus is placed outside the base of Ichthyopterygia (Jiang et al. 2016). The description of Utatsusaurus hataii Shikama, Kamei & Murata, 1978, presented another basal genus. This material was discovered in the Osawa Formation, Japan, and referred to the Subcolumites Zone, making it of Spathian age, similar to Grippia. The material consisted of several fragmented skeletons, with a well preserved pectoral limb as the focus of the study (Shikama et al. 1978). Svalbardosaurus crassidens (Mazin 1981) is considered a nomen dubium. The description is based off of loose, conical teeth and is not deemed diagnostic. The material was described to belong to an Early Triassic ichthyopterygian. Thaisaurus chonglakmanii (Mazin et al. 1991) was described based on several incomplete skeletons from Khao Thong, Thailand. The highly uncertain dating is based on poorly preserved ammonoidea and on morphological traits on the specimens themselves, only suggesting it to belong to the Early Triassic (Mazin et al. 1991). Upon discovery Parvinatator wapitiensis (Nicholls and Brinkman, 1995) from Sulphur Mountain Formation, Canada, was considered the oldest ichthyopterygian. It was later reassessed and does not hold this position anymore. The material consists of a skull and an articulated limb. Material previously assigned to Grippia from the Sulphur Mountain Formation, Canada, was reassessed by the description of Gulosaurus helmi (Cuthbertson et al. 2013). The reassignment was a necessity as the novel description was of the counterslab of the same specimen. The genus is regarded as a sister taxon to Grippia (Cuthbertson et al. 2013). Cartorhynchus lenticarpus (Motani et al. 2014) was described from Majishan Quarry, China. The material consists of a largely complete, articulated skeleton. The material was found within the Subcolumbites Zone, making it Spathian of age. Front limbs on the specimen were larger than usual in basal ichthyopterygians and may have allowed for limited terrestrial locomotion (Motani et al. 2014). In the description the genus is being situated outside of the Ichthyopterygia node, only nested at the base. The clade Nasorostra was erected with the description of Sclerocormus parviceps (Jiang et al., 2016) This specimen was also excavated from the Majishan Quarry, and assigned to the the Subcolumbites Zone. The material consists of skull and a partial postcranial skeleton. Cartorhynchus together with Sclerocormus make up the members of the novel clade as a sister taxon to Ichthyopterygia.

1.3 Historical review of Grippia The very first scientific description of the ichthyopterygian Grippia was published in 1929 by the Swedish paleontologist Carl Wiman. He had went on the Hamburg Spitsbergen Expedition to the eastern side of Spitsbergen the year before to collect fossil remains from the Triassic of Svalbard, and returned with what is now the holotype for the taxon. Wiman had gone on several expeditions to Svalbard in earlier years and published several articles on ichthyopterygian remains already (Wiman 1916a, 1922). The Grippia material he erected the genus on consisted of an articulated skull lacking the most distal rostrum, in addition to several loose limb elements and a piece of a jaw. The collection procedure was based on surface material and nodules, and the stratigraphic affinity was based on information provided by the palaeontologist E. Stensiö (Wiman 1929). With this he described the denominating species Grippia longirostris (Wiman 1929) along with the clade Grippidia. Unfortunately the holotype, the skull, was lost during bombing in Hamburg during the 2nd World War. But a cast of the holotype still exist to this date and serves as the functional holotype. Based on a morphological feature of the paddle elements Wiman proposed that Grippia as a basal ichthyopteryigan may have had hooves at the end of its digits, and compared this feature to the ornitischian dinosaur condition of the distal phalanges (Wiman 1929). Without any further traction, this idea failed to catch on. On a later expedition he collected additional surface material of the taxon, concretional material from different stratigraphical units. 15 additional specimens, including girdle elements, fragments of vertebral column and four partial skulls (Wiman 1933). The collection of additional material led to a revision of the description of the cranial sutures from the initial publication. Both descriptions of the skull sutures were questioned and redone by utilizing the cast of the holotype to create a cast of the type specimen (Mazin 1981). By doing so Mazin was attempting to avoid any bias from the markings on the cast itself. He was later criticized for including photographs which gave off distorted proportions and unclear diagnostic features (Motani 2000). In British Columbia, ichthyopterygian remains from the Early Triassic was uncovered (Brinkman et al. 1992) The material which consisted of an articulated thoraxic region was interpreted as Grippia until the counterslab was described as late as in 2013 and concluded that these remains had to belong to a different genus (Cuthbertson et al. 2013). In the meantime it had been proposed that the material may have belonged to a juvenile Parvinatator wapitiensis (Motani 1998). Brinkman et al. noted several anatomical differences such as centra that were taller than long, relatively longer humeri with differences in the angles of the distal facets, and were not completely content on placing it within the same species (Brinkman et al. 1992). This material was then

5 reassigned to the novel taxon Gulosaurus based on differences in the cranial sutures which the intial description of the specimen lacked (Cuthbertson et al. 2013). Gulosaurus was proposed within Grippidia, as a close relative of Grippia (Cuthbertson et al. 2013). The dentition of Grippia underwent a close reexamination when it became apparent that the teeth were set in shallow sockets in a dental groove, unlike previous descriptions (Motani 1997). And like another basal ichthyopterygian, Utatsusaurus, there were a lingual row of replacement teeth (Shikama et al. 1978). It was then proposed that the animal bore a second row of functional replacement teeth as seen in certain extant squamates (Motani 1997). This renounced the notion of strict durophagy in Grippia (Motani 1997). In 1998 Motani conducted preparational work on a nodule included in Wimans paper from 1933. In the paper the nodule showed one forelimb, but after careful mechanical preparation Motani managed to uncover yet another forelimb beneath the original one. This one was relatively well preserved and well depicted in Motanis paper (Motani 1998). The small size of the humerus together with the loose arrangement of the paddle elements led Motani to interpret the specimen as a juvenile (Motani 1998). Additional mechanical preparation was conducted on one of the partial skulls to uncover evidence for the basal ichtyopterygian condition on cranial sutures (Motani 2000). The preparation led to the discovery of novel similarities between the ichthyopterygian genera Utatsusaurus and Grippia (Motani 2000). The examination concluded with a reassignment of the specimen SVT 203 away from Grippia, possibly to Helveticosaurus, and to a disregard of the seemingly unjustified proposal set forth by Mazin that Grippia longirostris` rostrum ended abruptly (Motani 2000).

1.4 This study

Through this study a large amount of basal ichthtyopterygian remains were collected from a bonebed in the Grippia Niveau on the western slopes of Marmierfjellet. A thorough stratigraphical record was rendered which gives the material an age constraint useful in biogeographical as well as purely phylogenetic context. The strategic placement of Svalbard in the Early Triassic makes it an important piece of the puzzle connecting the localities of Southern China to the localities of British Columbia. Presenting a collection of well preserved, three-dimentional Grippia material larger than any collection previously described will open up for more extensive future comparative studies. This is especially exciting taken into account the scarce fragmentary material that has made up the diagnostic material of this genus for almost a hundred years. Hopefully this will add to our understanding of both the ecology

6 and the evolutionary history of these basal ichthyopterygians.

1.5 Geological setting

1.5.1 Svalbard in the Early Triassic The northern margin of the supercontinent Pangea (Figure 1) was lined by a large embayment of the Panthalassa Ocean where Svalbard was situated in the Triassic (Nystuen et al. 2013, Lundschien et al. 2014). This embayment, known as the Boreal Ocean, was enclosed by the North American part of Laurentia to the west, Greenland to the south west, Eurasia to the east, and the Canadian Arctic to the north west (Mørk 2015). Here, Svalbard made up a main constituent of a deep, cold water shelf (Wignall et al. 1998, Maxwell and Kear 2013, Dallmann et al. 2015). This deep, cold water shelf was being supplied by enormous amounts of sediment (Dallmann et al. 2015). The merging of the continents Laurentia and Kazakhstania had led to the forming of the Ural Mountains in the Permian, and sediments from erosional processes in these areas together with sediments from erosion of the Norwegian basement rock and from the Kola Peninsula contributed to a massive influx to the Boreal Ocean in the Triassic (Worsley 2008, Lundschien et al. 2014, Blomeier 2015). This led to an infilling of the shelf through the course of the Early to Middle Triassic (Lundschien et al. 2014). From the stratigraphy we may deduct a Changhsingian regression followed by a Changhsingian to Griesbachian transgression (Hallam and Wignall 1999).

Figure 3: Map of Svalbard with a stratigraphic outline over Flowerdalen, including surrounding areas. From Ekeheien 2016 (modified from Dallman 2015).

1.5.2 The Sassendalen Group The Triassic of Svalbard is dominated by the Sassendalen Group and the Kapp Toscana Group (Mørk et al. 1999). The Sassendalen Group, Early to Middle Triassic, is strictly marine while the overlying Kapp Toscana Group consists mostly of terrestrial deposits (Cox and Smith 1973). Present throughout the Triassic rocks on Svalbard is a distinct layer of hard siltstone, separating the two groups (Buchan et al. 1965). The Sassendalen Group is characterized by fine siliciclastics, cropping out in eastern and central parts of Spitsbergen (Vigran et al. 2014).

1.5.3 The Vikinghøgda formation

The stratigraphy of the Sassendalen Group is divided into Vardebukta, Sticky Keep and Botneheia Formations (Buchan et al. 1965). The Sticky Keep Formation corresponds to the upper part of the Vikinghøgda Formation, where Iskletten Member and Kaosfjellet Member correlate to Lusitaniadalen Member and Vendomdalen Member (Mørk et al. 1999). The Formation spans the Changhsingian Stage, Late Permian, to the boundary between the Olenekian Stage, Early Triassic, and the Anisian Stage, Middle Triassic (E. Nash 2016).

Figure 4: Stratigraphic log of Vikinghøgda Formation, Marmierfjellet. Modified from Hammer (2014), Mørk et al. (1999: fig 13) and Vigran et al. (2014: fig. 37a).

1.5.4 The Vendomdalen member

All members of the Sassendalen Group are deep shelf deposits from transgressive-regressive succession (Lundschien et al. 2014). The Vendomdalen Member is characterized by a 94 m thick transgression sequence. It consists of dark grey, silty, laminated mudstone, with yellow, weathering dolomite nodules and beds generated through storm events (Mørk et al. 1982, Mørk et al. 1999). The member has been dated to Spathian age with discoveries of the ammonoids Bajarunia euomphala, Keyserlingites subrobustus and Parasibirites grambergi whith their respective zones in lower, mid and upper parts (Mørk et al. 1999). Additional biostratigraphy, as palynological studies, have been correlated with magnetostratigraphy to provide a reasonably reliable placement in the geological record (Mørk et al. 1999b, Hounslow et al. 2000a, Hounslow et al. 2000b, Nakrem et al. 2008, Vigran et al. 2014).

1.5.5 The Grippia Niveau The Sassendalen Group was originally defined into three levels based on the characterizing vertebrate remains: The Fish Niveau, the Upper Saurian Nivau, and the Lower Saurian Niveau (Wiman 1910). An additional level, the Grippia Niveau, was added by Wiman in 1928, but referred to already in 1921 by Stensiö. The Grippia Niveau is located 33 m above the Fish Niveau and contains remains of the epynomous Grippia as well as other ichthyopteryigans, parasuchians, chondrichthyans and ammonoidea to name a few of the taxa (Stensiö 1921, Frebold 1930). The Niveaus of Wiman was the only divide of the Group until Buchan et al. suggested their stratigraphy in 1964. They have still been referred to in the literature through the years, even though they weren’t correlated to a strict stratigraphy until 2013 (Maxwell and Kear 2013).

1.5.6 The Grippia bonebed All material used in this study comes from one single bonebed located in the Grippia Niveau of Marmierfjellet, central Spitsbergen. The bonebed is located 17 m above the Fish Niveau and 25 m below the Lower Saurian Niveau. Thickness of the bed is approximately 4 cm. Bones, teeth and coprolites makes up the major constituents. Elements are in a size range from a few micrometer up to 20 cm. They are in different grades of wear, both heavily compressed and eroded specimens to seemingly unaltered specimens. XRD analysis reveals that the material is phosphatized, and the main substance is apatite, but pyrite and

10 dolomite/anchorite are present in the bonebed (Bratvold 2016). The pyrite might suggest anoxic water conditions. The presence of a lungfish tooth plate Ceratodus sp. may also suggest a more near shore environment than the one described by Mørk et al. 1999, the more plausible reason being storm depositions, events carrying the material out to the distal shelf (Berra 2001). The size of the material altogether and the lack of signs of saprotrophic organisms on the material are signs of the material being distally transported. Only a single invertebrate was discovered in the material from the bonebed. The lack of pelagic invertebrates with aragonitic shells may be caused by dissolution. Comparable bonebeds are found in Rhaetic, Late Triassic, sedimentary rocks across Europe (Korneisel et al. 2015). Similar depositions show signs of disturbed marine phosphatic and carbon cycles (Suan et al. 2012). With the biostratigraphical studies conducted on the Grippia Niveau, this bonebed is estimated to have an approximate age of 247,5 Ma.

Figure 5: Stratigraphic column for the Grippia bonebed and adjacent sedimentary units in detail. 1.Dark grey shale (~13cm), 2. Bonebed (~4cm), 3 and 5. Dark grey shale (~38cm), 4. Dolomite bed (~2cm),6. Shale with dolomite/anchorite concretions. 7. Fine bedded dark grey shale. From Ekeheien 2016.

2. MATERIAL AND METHODS

2.1 Excavation of the bonebed All material included in this study was collected on the 2015 expedition of The Spitsbergen Mesozoic Research Group (SMRG) to the Isfjorden area, central Spitsbergen. The Grippia bonebed, located in the Grippia Niveau referred to by Stensiö (1921) and named by Wiman (1929), was discovered after a prospecting expedition carried out by the SMRG to Marmierfjellet in 2014. Permits were obtained before the excavation was conducted, and the approved name of the locality appointed by the Norwegian Polar Directorate is used in this study. GPS coordinates of the Grippia bonebed: UTM N78 30521 E16 60118.

2.2 Material The bonebed consists of disarticulated, fragmentary fossil remains embedded in a dark grey or black colored shale matrix. Except for yellow dolomite nodules, the coloration of the bonebed is relatively homogenous. A high level of moisture caused by the high arctic environment made it hard to distinguish the fossil material from the matrix. The disarticulated and fragmentary nature of the material is typical of marine bonebeds with the reworking of elements by ocean currents (Blazejowski 2004). Some degree of compression is observed on parts of the material. This is a factor to consider in the analysis. In addition to remains of Grippia, the bonebed contains vertebrate material of fish, chondrichthyans and other marine reptiles. With the wide array of vertebrate elements found in the bonebed, it is of high importance to assert caution when describing the material. Of the Grippia material there was found elements of the vertebral column, of the paddles, of shoulder girdle and cranial elements. Only a selection of the best preserved material is figured in this thesis due to the high abundance of material. All elements are housed in the collections of the Natural History Museum, University of Oslo.

2.3 Field methods

Once the bonebed was exposed, it was divided into a grid of seven adjacent square meter quadrates. Each quadrate was subsequently collected by shoveling the entire layer of loose material into plastic bags. This was done to preserve a representative picture of the composition of material. Selected elements were either supported by a layer of aluminum foil

12 or jacketed due to their fragile state. In the case of plaster jacketing, a cover of wet paper towels was applied to the fossil to prevent plaster from coming in direct contact with the surface of the fossil elements. In addition, dark coloring was added to the mix of plaster to minimize any potential traces of human activity in case of spillage. The collected material was transported back to Longyearbyen by helicopter once it was brought back to camp. From Longyearbyen the material was shipped to mainland Norway, and eventually to the Natural History Museum in Oslo.

2.4 Laboratory methods

The material underwent sorting through a sieving process utilizing screen sizes of 2,00 mm, 1,00 mm, 0,50 mm, 0,25 mm, and 0,05 mm. Only material from the initial step of the sieving process (the 2,00 mm screen size) was used in this study. After rinsing and sieving, all material was air dried before further processing. The remaining factions were put in storage for later micropaleontological studies. Larger elements were treated in a ultrasonic bath, Bandelin Sonorex RK 255 Transistor. And fragmentary elements were glued using the cyanoacrylate adhesive Paleobond (type Jurassic gel4540).

2.5 Measurements and descriptive terminology All measurements in this study was performed by using a Cocraft digital caliper, down to the nearest mm. Only elements where cortical bone was preserved on the measuring areas were included. A standardized approach of measuring the dorsoventral, mediolateral and anteroposterior maximum of vertebral centra was followed.

The morphological descriptions of vertebral centra, jaw elements and dentition follow McGowan and Motani (2003).

3. DESCRIPTION OF MATERIAL

The extent of the collected material makes it notable in global context, and will certainly expand our understanding of the genus. The material described in this study was all collected from the Grippia bonebed as disarticulated, three dimensionally preserved elements. A varying degree of fragmentation has caused certain elements to only provide partial information, and therefore been interpreted with caution. Merriam 1908 has provided the basis for the assertion of elements together with the specific descriptions of the taxon. As the collected material consists entirely of disarticulated material, assigning each specimen to a specific genus relies on diagnostic features on each single element. Therefore, the material is in general referred to as a small ichthyopterygian instead of specifically placing the material within the genus.

3.1 Grippia

SYSTEMATIC PALAEONTOLOGY

ICHTHYOPTERYGIA Owen, 1840 GRIPPIOIDEA Ji et al., 2015 GRIPPIIDAE Wiman, 1933 GRIPPIA Wiman, 1929

Type species - Grippia longirostris Wiman, 1929.

Referred species - Type species only.

Locality and horizon - Lower Triassic (Spathian) of Svalbard.

Diagnosis - Small-sized ichthyopterygian. Rounded tooth crowns in posterior portion of jaws, multiple tooth rows on the maxilla (Motani 1997). Dorsal orientation of external naris; pre- and postfrontal completely separated; irregular margin of the anterior orbital; no lateral anterolateral orientation of pterygoid transverse flange; jugal and quadratojugal constitutes the

14 lower temporal arch; presence of manual pisiform (Ji et al. 2015). Lunate and shaftless metacarpal I, bicipital rib facet from cervical centra to posterior dorsal centra (Ji et al. 2015).

Overall 1-2 height/length ratio of vertebrae (Motani 2000).

Referred material - Cervical vertebra PMO 230.211, dorsal vertebra PMO 230.212, caudal vertebra PMO 230.213.

Remarks - A varying degree of fragmentation and distortion of the elements left 42 vertebral centra unidentified. 39 cervical-, 273 dorsal-, and 182 caudal centra were in condition to be asserted to respective axial regions, in all 493 identified centra.

3.2 Cranial elements Fragments of tooth bearing elements of a wide range of sizes were recognized from the collected material. Based on the organization of dentition and on the overall morphology, mandibular, maxillary and palatal elements were identified, in addition to one quadrate and one basioccipital. All elements are uncompressed with a varying degree of fragmentation.

3.2.1 Mandibular elements

54 separate specimens were identified as mandibular elements on the basis of displaying a single marginal tooth row with striated teeth. The specimens vary greatly in size and fragmentation.

Figure 6: Larger mandibular elements. A. Mandibular element 1 in labial view, B. Mandibular element 1 in occlusional view, C. Mandibular element 2 in labial view, D. Mandibular element 2 occlusional view. Scale equals 10mm.

In the dental description by Motani (1997), elements bearing conical teeth are assigned to the anterior portion of the mandibles, while the elements bearing blunted teeth are assigned to the posterior portions. Enamel infolding known as plicidentine is clearly visible in certain fragmenten elements (Fig. 6 D). All teeth displaying longitudinal striation are unlikely to have gone through extensive antemortem wear, and therefore display the original morphology of the teeth. Fragments from all parts of the jaw were found throughout the material. The presence of a dental groove may support Motanis suggestion of a subthecodont implantation (Fig. 6 and Fig. 7), but due to matrix covered roots it is not possible to confirm the presence of shallow sockets. The dentaries are identified by the orientation of striations, from anterodorsal to posteroventral (Motani 1997). On basis of this description, the elements lacking this striation are asserted to premaxilla (Fig. 7).

Figure 7: Smaller mandibular elements. A. Mandibular element 3 in labial view, B. Mandibular element 3 in occlusional view, C. Mandibular element 4 in labial view, D. Mandibular element 4 in occlusional view, E. Mandibular element 5 in labial view, F. Mandibular element 5 in occlusional view, G. Mandibular element 6 in labial view, H. Mandibular element 6 in occlusional view, I. Mandibular element 7 in labial view, J. Mandibular element 7 in occlusional view, K. Mandibular element 9 in labial view, L. Mandibular element 10 in occlusional view, M. Mandibular element 10 in occlusional view. Scale equals 10mm.

The general dentition contrasts that of many other basal ichthyopterygians being either completely edontolous (Chen et al. 2014, Motani 2014, Jiang et al. 2016) or displaying crushing teeth (Chen et al. 2013). The dentition of Utatsusaurus (Shikama et al. 1978) with acutely pointed conical teeth closely resembles the morphology in this material, which coincides Motanis comparison of dentition in Grippia and Utatsusaurus (1997).

3.2.2 Maxillae Three specimens were identified as maxillary elements on the basis of a secondary, lingual tooth row (Mazin 1981, Motani 1997) in addition to the marginal tooth row. All elements are

17 uncompressed and fragmented.

Figure 8: Maxillary elements. A. Maxillary element 1in occlusional view, B. Maxillary element 1in occlusional view, C. Maxillary element 1in occlusional view. Scale equals 10mm.

The two tooth rows are located on the same element, with no visible suture line. They are separated on two different levels in the same plane, the lingual row being posteriorly shifted relatively to the labial row (Motani 1997). The labial tooth row, the functional tooth row, consist of larger teeth than the lingual row in all three specimens. Both Grippia (Mazin 1981, Motani 1997) and Utatsusaurus (Shikama et al. 1978) display the organization of a secondary, lingual replacement tooth row.

3.2.3 Palatine Three elements were recognized as palatine on the basis of bearing teeth but lacking the organizational level of tooth rows (Wiman 1933). All three elements are uncompressed and fragmented.

Figure 9: Palatine elements. A. Palatine element 1 in occlusional view, B. Palatine element 2 in occlusional view, C. Palatine element 3 in occlusional view. Scale equals 10mm.

The elements all consists of a flat, bony plate with teeth imbedded ventrally. The teeth are bulbous and protrude marginally from the bone. The teeth lack striations, and are placed in a less orderly fashion compared to the mandibular and maxillary elements, as described by

Wiman (1933). All margins are eroded or fragmented, and does not provide any information about any sutures and placement in the palate.

3.2.4 Quadrate

The element is uncompressed, lacking the entire distal portion of the dorsal ascending lamina (Fig. 10). The articular condyle appears accentuated, adding to the overall stocky appearance of the element (Wiman 1933).

Figure 10: Left quadrate. A. In left lateral view, B. In ventral view. Dorsal ascending lamina is abbreviated ”dal”, articular condyle is abbreviated “ac”. Scale equals 10mm.

The stocky appearance of the central body resembles the element described and figured in Wiman (1933). The lacking portion of this element coincides with the portion covered by the squamosal and the quadratojugal in the described material (Wiman 1929, Wiman 1933), making up the entire distal portion of the dorsal ascending lamina (McGowan and Motani 2003). Because of this, it is hard to distinguish the element from the general mixosaurid quadrate (Jiang et al. 2005). The articular condyle is relatively large compared to certain other ichthyopterygians, Cartorhynchus (Motani et al. 2014) being an example. Still, there seem to be a trend in basal ichthyopterygian taxa such as Chaohusaurus (Chen et al. 2013) and Sclerocormus (Jiang et al. 2016) where the element accommodates for a heavy biting force.

3.2.5 Basioccipital

The element is uncompressed and largely intact, only lacking the basioccipital peg anteriorly. The element is recognized as a basal ichthyopterygian mainly on the basis of lacking the basioccipital tubera of basal sauropterygians (Rieppel 2000).

Figure 11: Basioccipital. The element A. posterior/occipital view, B. left lateral view. Notochordal pit is abbreviated “np”, basioccipital peg is abbreviated “bp”, extraoccipital facet is abbreviated “eof”, occipital condyle is abbreviated “oc”. Scale equals 10mm.

An abrupt end anteriorly marks the basis of the basioccipital peg. This is the only lacking portion of the element. Exoccipital facets are marginal, placed anterior most, dorsally, on the element (Fig. 11). The occipital condyle is convex, lacking a narrow neck as seen in certain basal sauropterygians (Rieppel et al. 2002). Unfortunately, the basioccipital in other basal ichthyopterygians is often missing (Chen et al. 2014, Jiang et al. 2016) or obscured in preservation (Shikama et al. 1978).

3.3 Appendicular skeleton

Numerous limb elements from a wide range of different sizes were identified. In contrast, no girdle elements were found. All specimens are uncompressed, with a decrease in fragmentation as the elements gets smaller.

3.3.1 Humeri

Three elements were identified as humerus. No compression, and fragmentation only in the larger of the three elements.

Figure 12: Humeri. A. Left humerus in dorsal view, B. left humerus in posterior view, C. left humerus in proximal view, D. left humerus in dorsal view, E. right humerus in proximal view, F. right humerus in dorsal

23 view. Dorsal process is abbreviated “dp”, radial facet is abbreviated “rf”, ulnar facet is abbreviated “uf”. Scale equals 10mm.

The humerus is highly compacted, slighty slimming down distally in posterior view (Fig. 12). The dorsal process is not as prominent as in other ichthyopterygians, most notably as in later, Jurassic taxa. Still, the proximal origin of the process marks the elements thickest region of the element. Ventrally there is no prominent deltopectoral crest. An extended radial facet together with the ulnar facet makes up the distal margin, no visible preaxial facet. The overall morphology is similar to the general basal ichthyopterygian humerus (Shikama et al. 1978).

3.3.2 ?Femur

One complete and one partial femur was identified. Both elements are uncompressed. The proximal dorsal process of the complete specimen is the main diagnostic feature of the element.

Figure 13: ?Femur. A. partial left femur in dorsal view, B. right femur in dorsal view. Proximal process is abbreviated “pp”, tibial facet is abbreviated “tf”, fibular facet is abbreviated “ff”. Scale equals 10mm.

The early descriptions of Wiman (1929) depicts an element displaying a morphology vastly different from the later forms of the Jurassic (McGowan and Motani 2003). The complete element (Fig. 13 B) has a profile resembling the profile of the humerus (Fig. 12 B, E), tapering off distally. The raised proximal region displays facets for girdle elements not found in the Grippia bonebed. The tibial facet is the larger of the two distal facets (Wiman 1933).

3.3.3 Radii and ulnae

Three uncompressed elements with different degrees of fragmentation were asserted to radius/ulna on the basis of the hourglass outline (Wiman 1933).

Figure 14: Radii/ulnae. A. dorsal view, B. posterior view, C. proximal view, D. in dorsal view. Scale equals 10mm.

The radii/ulnae resemble the general elongated form of most basal ichthyopterygians (Shikama et al. 1978, Chen et al. 2013, Motani et al. 2014). All elements are flattened and relatively robust. Width of distal articular surfaces exceeds the proximal articular surfaces (Wiman 1929).

3.3.4 Paddle elements A substantial portion of the collected material was identified as various paddle elements. The specimens are all flattened, and the general morphology varies from oval and rounded, disk like elements to biconcave and elongated elements. The collection of paddle elements suffer

26 from a small degree of fragmentation, without any evident compression or distortion.

Figure 15: Rounded elements. A. dorsal view, B. dorsal view, C. in dorsal view, D. in medial view, E. in medial view, F. in medial view, G. in dorsal view, H. in dorsal view, I. in dorsal view, J. in dorsal view. Scale equals 10mm.

The outline of the rounded, distal paddle elements vary from nearly circular to ovale and angled elements (Fig. 15). The outline of the proximal paddle elements maintain the elongated form similar to the radii/ulnae (Fig. 16), while the rounded disk like elements are positioned more distally in the paddle (Wiman 1929).

Figure 16: Metacarpals. A. dorsal view, B. dorsal view. Scale equals 10mm.

Throughout the paddle there are intermediates forms between the rounded, disk like and the elongated, biconcave elements (Fig. 16 A) This creates a gradient of morphs in the paddle (Wiman 1929). The size discrepancy of the specimens allocated to the paddles, as well as for the vertebral centra, are much higher than for any of the other types of elements.

3.4 Axial skeleton Vertebral elements makes up the main constituents of the material from the Grippia bonebed. From descriptions of Triassic marine reptiles (Merriam 1908) the elements have been classified into the different regions of the axial skeleton. Two different forms of vertebral centra were identified: Larger, discoidal elements of the genus Omphalosaurus, and smaller, cylindrical elements of the denominating Grippia. The elements of the latter display a wide size range.

3.4.1 Costae

All identified rib elements were highly fragmented, with no compression. A surprisingly small portion of the identified elements were assigned to ribs compared to the relatively high number of vertebral elements.

Figure 17: Rib heads and medial gastralia. A. bicipital rib head in medial view, B. medial gastralia in ventral view, C. unicipital rib head in medial view, D. medial gastralia in ventral view. Scale equals 10mm.

The elements follow a general ichthyopterygian rib morphology (McGowan and Motani 2003). Fig. 15 A is displaying a bicipital head, a diagnostic feature of ribs until the posterior dorsal region Grippia (Ji et al. 2015). The Y-shaped medial gastralia (Fig. 17 B, D), together with the rib heads, seem to have been preserved on the basis of being the more robust portion of the costae.

3.4.2 Cervical centra PMO 230.211 is uncompressed with a fragmented posterior face lacking the right lateral and ventral portions (Fig. 18 B). The element is assigned to the cervical region based on the presence of a parapophysis.

Figure 18: Anterior cervical centrum PMO 230.211. A. anterior view, B. posterior view, C. left lateral view, D. dorsal view. Neural canal is abbreviated “nc”, diapophysis is abbreviated “dph”, parapophysis is abbreviated “pph”. Scale equals 10mm.

The basal ichthyopterygian cervical centra display a minimal variation between taxa (Ji et al. 2015). The cervical centra of Grippia display a rather generalized morphology. Anterior face

30 of the centrum displays a hexagonal outline (Fig. 18 A), while the posterior face is hard to make out due to the fragmentary nature of the element (Fig. 18 B). All centra are deeply biconcave, the depression extending out towards the margins. Other cervical elements show a rounded outline on the posterior outline in contrast to the anterior outline. The mediolateral width of the element marginally exceeds the dorsoventral height, and the dorsoventral height exceeds the anteroposterior length. The height/length ratio of this element is representative for the cervicals as they appear to be an exception to the general 1-2 centrum ratio in in Grippia (Motani 2000). The complete separation between the diapophysis and the parapophysis places this element anteriorly in the cervical region (Fig. 18 C). The neural canal makes a shallow groove narrowing in to the anteroposterior midline between the two neural facets, and extends symmetrically anteriorly and posteriorly (Fig. 18 D).

3.4.3 Dorsal centra PMO 230.212 is uncompressed, with a fragmentary posterior face lacking the left lateral and dorsal portions (Fig. 19 B). The element is assigned to the dorsal region on basis of the lack of distinct parapophyses.

Figure 19: Anterior dorsal centrum PMO 230.212. A. anterior view, B. posterior view, C. left lateral view, D. dorsal view. Neural canal is abbreviated “nc”, diapophysis is abbreviated “dph”. Scale equals 10mm.

A blunted hexagonal outline on the anterior face defines this element as an anterior dorsal centrum. As for the cervicals, the posterior face is more rounded than the anterior. The mediolateral width of the element exceeds the dorsoventral height to a greater extent than in the cervical previously described. The height/length ratio is still not at 1-2 in the anterior dorsal centra. A patch of smooth periosteal bone covers the dorsal margin anterior to the apophysis (Fig. 19 C). This marks an area of the element not included in articulation with the rib heads. The apophyses extend from the anterior margin past the patch of periosteal bone in an approximate angle of 50° (Fig. 19 C). The floor of the neural canal is deeply and narrowly excavated, and the facets for the neural arch are less prominent than in the cervicals (Fig. 19 D).

3.4.4 Caudal centra PMO 230.213 is uncompressed and less fragmentary than the two previous vertebral elements. The element is elongated anteriorposteriorly, and possesses an anterioposterior ridge mid dorsoventrally.

Figure 20: Mid caudal centrum PMO 230.213. A. anterior view, B. posterior view, C. left lateral view, D. dorsal view. Neural canal is abbreviated “nc”, anteroposterior ridge is abbreviated “apr”. Scale equals 10mm.

The anterior and posterior faces are less heterogeneous than in the anterior regions of the vertebral column. Mediolateral width is near the dorsoventral. Lateral compression and anteroposterior elongation of the element results in a heigth/length ratio closer to 1-2. As mentioned, a prominent anterorposterior ridge is present mid dorsoventrally (Fig. 20 C), running the length of the element. The floor of the neural canal is shallow and maintains a slight biconcavity (Fig. 20 D).

3.4.5 Apophyses

One of the diagnostic features listed is the bicipital rib articulation from the anterior most region to the posterior dorsal centra (Ji et al. 2015). The material collected from the Grippia bonebed display a relatively static orientation of the apophyses throughout the dorsal region.

Figure 21: Vertebral column in left lateral view. A. anterior cervical, B. mid cervical, C. posterior cervical, D. anterior dorsal, E. mid dorsal, F. posterior dorsal, G. anterior caudal, H. mid caudal, I. posterior caudal, J. distal caudal. Due to scaling of certain objects for comparative purposes, no scale is presented.

From the anterior portion of the cervical region the apophyses are completely separated (Fig. 21 A). The separation of periosteal bone becomes slighter in the mid cervicals (Fig. 21 B), and in the posterior cervicals (Fig. 21 C) the separation disappears, leaving the points of articulation on different levels of the same curve. The anterior dorsals (Fig. 21 D) retains a patch of periosteal bone anterior to the apophyses which constitutes a continuous band in a 50°. In the mid dorsals (Fig. 21 E) the continuous band of the merging apophyses is less curved, and the patch of periosteal bone has disappeared. The apophyses in the posterior dorsals (Fig. 21 F) retract towards the anterior and dorsal margin of the element, while maintaining the same angle. The caudal region is lacking apophyses altogether, only displaying a vestige on the anterior and dorsal margin in the anterior caudals (Fig 21. G). The anteroposterior ridge (Fig. 20 B) begins as an enlarged area on the anterior margin in the anterior caudals (Fig. 21 G), is fully developed in the mid caudals (Fig. 21 H), and is already retracted in the posterior caudals (Fig. 21 I). From the mid caudals and posteriorly in the vertebral column there is a clear anteroposterior elongation of the elements, in addition to a gradual lateral compression.

4. DISCUSSION 4.1 Articulation of the quadrate

The jaw joint in ichthyopterygians consists of the point of articulation between the articular condyle of the quadrate and the saddle shaped articular surface of the articular (McGowan and Motani 2003). The morphology of the articular surface of these elements dictates the function, and is highly indicative of the feeding mode of the taxa (Collin and Janis 1997). Ichthyopterygia is a large taxon with representatives displaying a wide range of different feeding mechanisms reflected in their respective dentition and jaw morphology (McGowan and Motani 2003).

4.1.1 The ichthyopterygian quadrate

The general morphology of the ichtyopterygian quadrate remains relatively constant through the geological periods (Appleby 1961). A dorsal ascending lamina being overlaid by the squamosal and quadratojugal makes up the dorsal portion of the element, commonly leaving only the articular condyle visible in lateral view of articulated skulls (Wiman 1929). The form and function of the condyle is the portion of the element subjected to the majority of morphological variation. Basal ichthyopterygian material is limited, and does not provide the same basis of comparison as the later taxa. However, basal taxa still display a variety of condyles, mainly in the degree of robustness. Of the described taxa, Grippia (Wiman 1929) and Utatsusaurus (Shikama et al. 1978) are some of few taxa displaying tooth bearing elements. Other edontolous taxa such as Cartorhynchus (Motani et al. 2014) and Sclerocormus (Jiang et al. 2016) still display a robust articular condyle and are believed to have been able to deliver a strong bite in spite of being described as suction feeders.

4.1.2 The quadrate

The relatively large articular condyle of the element is being supported by the robust extracondylar area of the element (Fig. 12). The overall stocky appearance of the element would have provided the animal with a sturdy jaw joint able to withstand high degrees of stress and tension. In Wimans descriptions of Grippia he briefly comments on the stocky appearance of the element without devoting it more attention (1933). The three dimensional,

36 disarticulated element provides possibilities for further analysis and assessment. The ventral view of the element (Fig 12. B) reveals a greater surface than depicted and described in the existing literature.

4.1.3 Form and function of the quadrate

Dentition and jaw morphology are features highly indicative of feeding mode and ecological niches, and therefore emphasized in the literature (Hieronymus 2006). Comparisons of elements involved in the functional jaw joint have been subject of extensive analysis to determine phylogenetic relationship of Mesozoic marine reptiles to ancestral terrestrial taxa (DeBraga et al. 1993). With few transitional specimens in the fossil record, comparative studies have been essential to gain an understanding of the evolutionary descent of various marine reptile taxa (Nopcsa 1903). The quadrate in several extant and extinct diapsid taxa have been detrimental in these comparative studies, and therefore undergone thorough analysis. The element is displaying the most robust basal ichthyopterygian articular surface of the quadrate described. With the variability of feeding modes and in morphologies of the jaw joint in basal ichthyopterygia, the element resembles the robust form of the suction feeding taxa. In contrast to these edontolous taxa, Grippias numerous tooth bearing elements points to a very different ecological niche. From a specimen earlier assigned to Grippia with remains of cephalopod and annelid hooks in the stomach region (Buchy et al. 2004), it is possible to deduct a possible diet of the genus. Even though this specimen no longer is recognized as belonging to the same taxon, the similar small ichthyopterygian morphology of the elements, and the locality of Lower Triassic Spitsbergen makes the stomach contents of this specimen highly comparable to Grippia. Robust jaws bearing acute, conical teeth in addition to palatal dentition would suit a predatory niche focusing on catching, possibly crushing, cephalopod shells perfectly.

4.2 Outline of the body The thunniform body of Jurassic ichtyopterygians is a hydrodynamic adaptation for high velocity swimming (Buchholtz 2001). The generalized body form of derived ichthyopterygians differs greatly from the more anguilliform bodies of basal taxa as they inhabited a greater range of different niches (Ji et al. 2015). Vertebral centra are a good

37 indicator of the outline of the body as the apophyses affects the outline of the body (Merriam 1908).

4.2.1 The basal ichthyopterygian body plan

As form and function are inherently connected, the anguilliform swimming mode of numerous basal ichthyopterygian taxa is deducted from the body plan (Houssaye et al. 2014). Lacking the same level of heterogenous placement of the apophyses along the vertebral colum, the body plan of several basal ichthyopterygian taxa resembles an ancestral terrestrial form (McGowan 1986). Sclerocormus (Jiang et al. 2016) and Eohupesuchus (Chen et al. 2014) are both examples of this, as well as Grippia.

4.2.2 The dorsal vertebral centra of Grippia

Of the vertebral centra collected from the Grippia bonebed, the vast majority were asserted to the dorsal region with 273 dorsal centra out of a total number of 494 elements. Of the remaining centra, 39 were asserted to the cervical region, and 182 to the caudal region. This relatively high number may be affected by a preservation bias favoring the dorsal centra. Another possibility is the process of asserting centra to the different regions of the spinal column could be flawed. The vertebral formula of Grippia is yet to be described in detail, and requires articulated specimens to determine. All dorsal centra asserted to Grippia in the collected material from the Grippia bonebed display little variation in the morphology. The two main features in lateral view of the spinal column is the overall length and outline of the elements, and the form and placement of apophyses (Fig. 23). The outline of the elements in lateral view gradually increases in anteroposterior length from anterior to posterior centra, a trend continuing posteriorly to the distal most caudals. The apophyses display little variation. In thunniform taxa, the apophyses move in a dorsoventral plane, affecting the articulation of the rib heads to the spinal column, and in turn affecting the overall outline of the body of the animal (Motani et al. 1996). This relatively homogenous articulation of rib heads along the dorsal region in Grippia is an indication of a much less curved outline of the body. Thusly, Grippia seem to display an anguilliform body, similar to several basal ichthyopterygian taxa (Ji et al. 2015). One reason to maintain such a body form is the usage of hind limbs in locomotion (Buchholtz 2001). Prominent hind limbs are described in several basal ichthyopterygian taxa (Chen et al. 2013). Only two femurs were identified as hind limb

38 elements from the collected material, and future studies will hopefully shed more light on the hind limbs of Grippia.

2 1.8 1.6 1.4 1.2 1 0.8 0.6 0.4 0.2

10 19 28 37 46 55 64 73 82 91

109 118 127 136 145 154 163 172 181 190 199 208 217 226 235 244 253 262 271 100

Figure 22: Height to length ratio of dorsal centra.

In Motani 2000 an approximate 1-2 height to length ratio of the dorsal centra in Grippia is listed as a diagnostic feature. Of the 273 dorsal centra identified and measured, only a minority of elements were close to the requirement. As the Grippia material available have been severely limited until now, sample size bias may have had an effect on the ratio.

4.2.3 The distal most caudal centra of Grippia

The gradual anteroposterior elongation of vertebral centra increases from the anterior dorsal region and all the way to the posterior caudal region of the spinal column (Fig. 23 J). The elements of this region do achieve the 1-2 ratio stated in Motani 2000, even though the elements clearly do not belong to the dorsal region. The distal most caudal elements are in addition to the extensive elongation also highly laterally compressed. This is a state analogous to other diapsid taxa such as diplodocids (Myhrvold and Currie 1997) and Triassic turtles (Schoch and Sues 2015). The homogenous elements distal most in the caudal region creates a whip like tail (Houssaye 2009). Whether the tail were used for defensive purposes is difficult to assess. However, this contrasts the general outline of the ichthyopterygian body, not displaying a propulsive tail fluke as derived taxa (Ji et al. 2015).

4.3 Size discrepancy and taxonomic certainty This collection of Grippia material is inequivalent in size. The larger sample size presents an increase in variation, both morphologically and in the size range of the elements. Certain specimens display a relatively large size discrepancy, especially mandibular elements, vertebral centra and paddle elements. The vertebral centra vary in anteroposterior length from over 22 mm to less than 3 mm. This may reflect different ontogenetic stages, ranging from juveniles to adult individuals. This novel data of variation in size expand our understanding of the genus, and allows for future, more quantitative oriented studies. Despite displaying such a wide range of element sizes, the majority of the material belongs to the lower range of the scale. A striking 86 percent of the vertebral material does not exceed the mid-range. The reasons behind this distribution could be linked to the preservation of the bonebed. The reworking of material on the seafloor may favor the smaller elements as the larger vertebral centra might succumb to the process and fragment (Rogers and Eberth 2007). The possibility of the size distribution mirroring the composition of the population is however minimal. As the entire collection of material is disarticulated, and the diagnostic features of Grippia are severly limited, it is difficult to assert the material to the genus with certainty. The material is therefore described as small to mid-sized basal ichtyopterygian elements. However, the likelihood of the material belonging to Grippia is high, and hopefully future studies will shed more light on the matter.

5. CONCLUSION

The basal ichthyopterygian remains collected from the Grippia bonebed during the NHM field season of 2015 provides some of the best preserved material described. Three dimensionally preserved elements from all regions of the body, with minimal to no degree of compression or distortion, presents invaluable information about the state of the basal ichthyopterygians on Spitsbergen.

In the various states of jaw morphologies among basal ichthyopterygians, an expanded area of articulation is not a unique trait for this element. The edentulous jaws of the taxa with expanded articular surfaces contrasts this material where the vast majority of jaw elements were tooth bearing.

The orientation of the apophyses along the vertebral column does not vary as much as in other ichthyopterygian taxa. This trait does show correlation with the general body outline and is highly affected by the mode of locomotion, most often associated with an anguilliform swimming mode.

The Grippia bonebed has yielded enough material to sustain work for years to come, and is bound to provide novel information for the basal ichthyopterygians. As extent of described material of Early Triassic ichthyopterygians is somewhat limited, this collection is unique to the international research community, and undoubtedly exciting for future studies.

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7. APPENDICES

* all measurements given in mm

* “-” marks damaged area of specimen/dorsal centra lacking facets

* “A-P” – anteroposterior, “D-V” – dorsoventral, “M-L” – mediolateral

7.1 Measurements of cervical centra

SPECIMEN A-P D-V M-L width M-L width Min. Max. D-V height / D-V height / length height including facets excluding facets neural neural A-P length M-L width canal canal (exluding facets)

Cervical #1 (figured in 9,75 11,42 13,03 11,79 4,22 5,6 1,171282 0,968617 Ekeheien 2016) Cervical #2 10,21 14,42 16,09 15,2 4,97 7,71 1,412341 0,948684 Cervical #3 7,67 10,56 12,4 9,81 3,3 4,98 1,376793 1,076453 Cervical #4 7,18 10,03 10,21 8,81 3,12 3,65 1,396936 1,138479 Cervical #5 - 10,01 9,56 9,04 3,47 5,46 - 1,107301

Cervical #6 7,66 9,47 8,29 7,3 2,58 4,17 1,236292 1,29726 Cervical #7 7,01 7,69 7,45 6,65 3,25 4,76 1,097004 1,156391 Cervical #8 5,37 6,68 5,62 4,83 2,01 3,95 1,243948 1,383023 Cervical #9 6,32 6,83 7,96 7,56 2,85 4,69 1,080696 0,903439 Cervical #10 6,25 6,66 6,91 6,23 2,15 4,44 1,0656 1,069021 Cervical #11 8,9 10,09 9,72 8,49 3,09 4,55 1,133708 1,188457 Cervical #12 6,38 6,93 7,59 7,1 2,74 3,78 1,086207 0,976056 Cervical #13 5,74 7,42 7,64 5,83 2,71 4,01 1,292683 1,272727 Cervical #14 3,61 3,09 4,28 3,73 1,94 3,1 0,855956 0,828418 Cervical #15 3,63 2,76 3,6 3,17 2,4 2,51 0,760331 0,870662 Cervical #16 4,16 3,99 5,25 4,91 2,88 3,16 0,959135 0,812627 Cervical #17 5,02 4,96 5,59 5,01 2,39 3,96 0,988048 0,99002 Cervical #18 5,09 5,14 5,33 5,09 2,72 3,49 1,009823 1,009823 Cervical #19 4,96 4,32 6,41 5,2 3,03 4,18 0,870968 0,830769 Cervical #20 6,05 6,9 8,01 7,06 2,62 2,86 1,140496 0,977337 Cervical #21 3,42 3,62 4,44 4,05 1,81 2,84 1,05848 0,893827 Cervical #22 5,25 4,91 5,32 4,73 - - 0,935238 1,038055 Cervical #23 5,41 5,5 5,2 4,57 - - 1,016636 1,203501 Cervical #24 4,45 3,29 4,16 3,61 1,91 2,61 0,739326 0,911357 Cervical #25 3,67 3,87 3,83 3,31 1,67 2,26 1,054496 1,169184 Cervical #26 5,02 4,66 5,03 4,51 - 3,29 0,928287 1,033259 Cervical #27 6,21 7,78 8,08 7,77 1,98 2,93 1,252818 1,001287 Cervical #28 8,86 8,87 - - - - 1,001129 -

Cervical #29 6,28 7,6 8,43 7,67 2,05 2,93 1,210191 0,990874 Cervical #30 5,43 6,17 6,47 6,01 2,08 3,83 1,13628 1,026622 Cervical #31 4,52 4,24 5,35 4,84 - - 0,938053 0,876033 Cervical #32 9,06 13,27 13,51 12,11 2,82 4,57 1,46468 1,095789 Cervical #33 7,36 8,61 9,93 8,08 2,3 3,64 1,169837 1,065594 Cervical #34 10,58 13,5 14,34 - 3,07 4,18 1,275992 - Cervical #35 9,13 10,62 9,92 8,71 2,21 4,88 1,163198 1,219288 Cervical #36 9 6,97 - 8,6 - - 0,774444 0,810465 Cervical #37 9,38 9,68 8,48 7,77 1,63 3,47 1,031983 1,245817 Cervical #38 5,99 6,07 5,03 - 1,47 2,73 1,013356 - Cervical #39 4,06 4,52 4,33 3,66 - 2,33 1,1133 1,234973

7.2 Measurements of dorsal centra

SPECIMEN A-P D-V M-L width M-L width Min. Max. D-V height / D-V height / length height including facets excluding facets neural neural A-P length M-L width canal canal (exluding facets)

Dorsal #1 (figured in 9,81 11,8 14,06 13,84 3,39 6,16 1,202854 0,852601 Ekeheien 2016) Dorsal 8,9 9,59 9,44 7,81 2,78 4,34 1,077528 1,227913 #2 Dorsal 10,43 9,89 9,97 - 3,08 5,45 0,948226 -

#3 Dorsal 5,87 9,79 8,72 8,8 2,81 4,49 1,667802 1,1125 #4 Dorsal 10,79 10,44 12,06 10,39 4,41 5,63 0,967563 1,004812 #5 Dorsal 8,68 10,34 9,89 8,93 4,13 5,68 1,191244 1,157895 #6 Dorsal 8,82 11,8 10 9,07 4,49 5,98 1,337868 1,300992 #7 Dorsal 9,03 11,86 10,16 9,74 3,17 4,71 1,3134 1,217659 #8 Dorsal 7,48 10,51 8,1 6,69 2,81 4,18 1,40508 1,571001 #9 Dorsal #10 6,67 9,6 8,62 7,82 2,49 4 1,43928 1,227621 Dorsal #11 6,96 9,47 8,82 8,72 2,66 3,89 1,360632 1,086009 Dorsal #12 8,89 8,51 9,77 8,25 3,33 5,15 0,957255 1,031515 Dorsal #13 6,66 8,6 9,35 7,85 3,69 5,66 1,291291 1,095541 Dorsal #14 8,96 10,89 10,97 9,19 3,24 4,59 1,215402 1,184984 Dorsal #15 7,67 9,19 8,54 8,16 - - 1,198175 1,126225 Dorsal #16 6,63 7,75 8,24 7,19 3,32 4,78 1,168929 1,077886 Dorsal #17 8,44 9,05 9,17 8,32 2,79 4,56 1,072275 1,08774 Dorsal #18 7,9 11,3 12,57 - 3,7 4,6 1,43038 - Dorsal #19 8,09 11,45 11,06 10,34 2,6 3,9 1,415328 1,10735

Dorsal #20 10,36 11,35 11,86 - 2,11 4,14 1,09556 - Dorsal #21 6,61 10,1 12,7 11,25 3,48 4,47 1,527988 0,897778 Dorsal #22 6 8,47 8,36 6,47 1,48 2,72 1,411667 1,309119 Dorsal #23 8,76 7,86 8,2 - 2,99 3,73 0,89726 - Dorsal #24 7,36 7,88 9,61 8,6 4,69 4,9 1,070652 0,916279 Dorsal #25 8,28 8,96 10,01 8,58 2,79 5,09 1,082126 1,044289 Dorsal #26 7,55 11,11 9,56 - 2,09 3,55 1,471523 - Dorsal #27 6,5 10,28 11,35 10,22 2,95 4,63 1,581538 1,005871 Dorsal #28 8,63 7,95 6,8 6,03 2,35 3,67 0,921205 1,318408 Dorsal #29 6,41 7,37 8 7,03 3,22 4,15 1,149766 1,048364 Dorsal #30 7,12 9,13 8,25 7,28 2,36 4,05 1,282303 1,254121 Dorsal #31 7,16 8,01 - 7,33 2,18 4,4 1,118715 1,092769 Dorsal #32 7,51 7,88 8,05 7,12 3,11 4,07 1,049268 1,106742 Dorsal #33 8,48 12,31 12,35 10,74 3 5,18 1,451651 1,146182 Dorsal #34 5,62 6,12 6,87 5,29 2,2 3,9 1,088968 1,1569 Dorsal #35 5,55 6,47 6,38 5,22 3,43 4,1 1,165766 1,239464 Dorsal #36 6,56 7,96 5,96 5,72 1,95 2,92 1,213415 1,391608 Dorsal #37 6,13 8,1 8,78 6,93 3,33 4,45 1,32137 1,168831 Dorsal #38 9,59 9,95 12,12 9,71 3,24 5,59 1,037539 1,024717 Dorsal #39 9,29 8,2 8,34 8,11 2,43 4,31 0,88267 1,011097 Dorsal #40 9,47 11,36 11,52 10,22 2,07 4,71 1,199578 1,111546 Dorsal #41 8,91 10,76 8,97 8,71 2,64 4,35 1,207632 1,235362 Dorsal #42 8,23 8,86 7,68 - - - 1,076549 -

Dorsal #43 6,06 8,33 7,04 6,57 2,84 3,15 1,374587 1,267884 Dorsal #44 5,83 7,24 7,61 7,45 3,2 4,17 1,241852 0,971812 Dorsal #45 7,85 10,87 9,8 9,6 3,07 4,64 1,384713 1,132292 Dorsal #46 9,5 7,72 8,56 7,47 2,94 4,76 0,812632 1,033467 Dorsal #47 8,18 9,48 9,1 - 2,04 3,68 1,158924 - Dorsal #48 6,17 8,06 8,03 7,49 2,77 3,91 1,306321 1,076101 Dorsal #49 10,06 11,25 8,76 8,93 2,72 4,87 1,11829 1,259798 Dorsal #50 8,57 11,52 11,02 9,59 - - 1,344224 1,201251 Dorsal #51 7,73 8,08 6,83 6,37 1,51 4,08 1,045278 1,268446 Dorsal #52 6,99 5,18 6,99 5,93 2,17 3,53 0,741059 0,873524 Dorsal #53 5,72 8,07 7,84 6,89 - 3,21 1,410839 1,171263 Dorsal #54 6,28 8,13 7,78 7,05 2,85 3,64 1,294586 1,153191 Dorsal #55 7,72 12,2 11,52 10,15 3,02 3,77 1,580311 1,20197 Dorsal #56 7,45 7,26 7,2 6,48 2,22 3,2 0,974497 1,12037 Dorsal #57 8,68 8,72 9,64 7,57 2,98 3,47 1,004608 1,151915 Dorsal #58 8,5 - - 11,07 - - - - Dorsal #59 11,36 11,93 13,92 12,5 2,23 4,31 1,050176 0,9544 Dorsal #60 8,86 10,78 10,96 10,48 2,75 3,3 1,216704 1,028626 Dorsal #61 - 13,45 13,46 - 3,28 4,63 - - Dorsal #62 9,99 9,38 10,4 9,35 - - 0,938939 1,003209 Dorsal #63 8,04 - 8,18 - - - - - Dorsal #64 9,08 11,8 10,8 10,09 1,75 2,02 1,299559 1,169475 Dorsal #65 - 12,24 11,98 - - 2,95 - -

Dorsal #66 10,82 11,4 10,93 - 3,24 4,25 1,053604 - Dorsal #67 7,2 10,08 8,97 - 2,74 3,3 1,4 - Dorsal #68 10,22 9,9 9,59 - 2,96 3,62 0,968689 - Dorsal #69 8,07 11,4 10,95 9,13 - 2,55 1,412639 1,248631 Dorsal #70 7,05 11,36 13 11,95 - 3,39 1,611348 0,950628 Dorsal #71 7,02 7,32 7,15 - 2,36 3,07 1,042735 - Dorsal #72 7,02 9,8 7,44 7,03 - - 1,396011 1,394026 Dorsal #73 7,89 10,58 10,95 9,88 - - 1,340938 1,07085 Dorsal #74 7,72 9,53 9,68 - 2,09 2,71 1,234456 - Dorsal #75 11,04 11,82 10,34 - 2,53 4,71 1,070652 - Dorsal #76 9,08 12,7 12,61 - 2,02 4,37 1,398678 - Dorsal #77 8,02 ------Dorsal #78 8,44 9 9,4 7,76 - - 1,066351 1,159794 Dorsal #79 12,02 14,66 10,93 - 2,54 4,78 1,219634 - Dorsal #80 12,08 12,81 10,16 8,05 2,02 4,04 1,06043 1,591304 Dorsal #81 12,29 11,45 12,54 12,18 - 5,01 0,931652 0,940066 Dorsal #82 11,3 13,2 - 9,38 - - 1,168142 1,407249 Dorsal #83 7,63 10,92 9,26 8,64 2,83 3,99 1,431193 1,263889 Dorsal #84 10,43 10,35 9,66 - 2,02 3,76 0,99233 - Dorsal #85 8,74 9,11 8,02 - 2,45 3,45 1,042334 - Dorsal #86 7,4 7,64 7,89 7,65 2,13 3,39 1,032432 0,998693 Dorsal #87 6,19 6,52 4,25 4,85 - 2,68 1,053312 1,34433 Dorsal #88 6,03 6,14 4,4 3,92 - - 1,018242 1,566327

Dorsal #89 8 5,18 - 4,23 - 2,39 0,6475 1,224586 Dorsal #90 7,32 6,99 7,16 6,24 2,7 3,05 0,954918 1,120192 Dorsal #91 6,72 6,09 5,72 5,61 1,57 2,61 0,90625 1,085561 Dorsal #92 5,65 5,38 5,04 4,9 - 2,44 0,952212 1,097959 Dorsal #93 5,2 5,88 5,57 5,7 1,98 2,84 1,130769 1,031579 Dorsal #94 5,46 5,37 5,18 4,55 1,88 2,53 0,983516 1,18022 Dorsal #95 6,78 4,87 6,18 6,24 - 2,04 0,718289 0,780449 Dorsal #96 6,47 6,02 5,84 4,81 2,6 2,83 0,930448 1,251559 Dorsal #97 5,93 5,54 5,24 4,73 2,17 3,08 0,934233 1,171247 Dorsal #98 4,53 5,38 5,48 4,79 1,81 2,6 1,187638 1,123173 Dorsal #99 5,38 4,41 4,61 4,58 - - 0,819703 0,962882 Dorsal #100 4,96 5,02 4,73 4,65 1,7 2,73 1,012097 1,07957 Dorsal #101 6,39 6,57 6,74 5,59 2,04 2,99 1,028169 1,175313 Dorsal #102 7,01 6,18 6,31 6,19 2,73 - 0,881598 0,998384 Dorsal #103 6,76 5,59 6,43 - - 3,5 0,826923 - Dorsal #104 5,95 5,98 - 5,09 1,47 1,89 1,005042 1,174853 Dorsal #105 5,26 4,25 6,17 5,28 2,34 2,93 0,807985 0,804924 Dorsal #106 5,14 5,34 5,66 4,72 2,08 2,9 1,038911 1,131356 Dorsal #107 5,17 5,84 5,27 4,43 2,08 2,98 1,129594 1,318284 Dorsal #108 6,27 5,47 - 4,01 2,13 2,23 0,872408 1,36409 Dorsal #109 6,59 4,7 5,4 5,19 1,91 2,3 0,713202 0,905588 Dorsal #110 6,25 5,55 4,78 4,19 - - 0,888 1,324582 Dorsal #111 6,93 5,17 4,08 3,52 1,87 2,43 0,746032 1,46875

Dorsal #112 3,96 7,01 5,55 5,34 2,26 2,63 1,770202 1,312734 Dorsal #113 6,61 6,05 6,63 5,71 2,14 3,56 0,91528 1,059545 Dorsal #114 5,56 5,17 5,43 5,07 2,32 3,14 0,929856 1,019724 Dorsal #115 5,46 4,3 6,25 5,13 2,33 2,24 0,787546 0,838207 Dorsal #116 4,62 4,05 4,74 4,55 2,27 3,11 0,876623 0,89011 Dorsal #117 5,06 6,18 6,92 6,07 3,03 4,24 1,221344 1,018122 Dorsal #118 4,97 5,6 5,81 5,31 2,67 3,85 1,126761 1,054614 Dorsal #119 6,45 4,85 5,58 4,65 2,07 2,66 0,751938 1,043011 Dorsal #120 4,49 4,17 4,24 4,26 1,92 2,59 0,928731 0,978873 Dorsal #121 4,07 4,43 4,78 3,97 - - 1,088452 1,115869 Dorsal #122 7,28 4,7 5,36 4,68 1,72 2,58 0,645604 1,004274 Dorsal #123 3,61 5,25 5,74 5,49 2,49 2,4 1,454294 0,956284 Dorsal #124 4,36 4,63 4,72 4,1 1,98 2,58 1,061927 1,129268 Dorsal #125 5,11 4,73 4,83 - 1,61 2,41 0,925636 - Dorsal #126 4,63 3,58 3,79 - 1,32 1,64 0,773218 - Dorsal #127 5,28 5,2 5,19 4,5 - - 0,984848 1,155556 Dorsal #128 5,04 4,96 4,67 4,42 2,1 2,88 0,984127 1,122172 Dorsal #129 5,89 7,09 6,67 5,1 2,5 3,12 1,203735 1,390196 Dorsal #130 4,6 5,64 3,91 3,55 - - 1,226087 1,588732 Dorsal #131 4,59 4,52 4,73 4,42 2,62 2,99 0,984749 1,022624 Dorsal #132 4,23 4,64 4,57 4,38 2,18 3,06 1,096927 1,059361 Dorsal #133 5,63 5,82 5,71 - 1,43 2,58 1,033748 - Dorsal #134 5,55 5,71 5,9 - 1,93 3,08 1,028829 -

Dorsal #135 4,61 4,16 4,67 4,16 - - 0,902386 1 Dorsal #136 5,37 5,09 4,87 4,34 1,99 3,14 0,947858 1,172811 Dorsal #137 5,47 4,51 4,85 4,24 2,33 2,83 0,824497 1,063679 Dorsal #138 4,12 3,87 4,13 3,77 - - 0,93932 1,026525 Dorsal #139 4,47 4,35 4,78 3,52 2,12 2,8 0,973154 1,235795 Dorsal #140 3,93 3,92 4,1 3,75 1,75 2,51 0,997455 1,045333 Dorsal #141 7,18 - 6,99 - 2,83 4,54 - - Dorsal #142 4,39 5,09 4,11 4,14 - - 1,159453 1,229469 Dorsal #143 5,54 6 5,96 - 1,84 2,39 1,083032 - Dorsal #144 3,97 4,17 4,04 3,49 2,07 2,69 1,050378 1,194842 Dorsal #145 5,11 3,99 5,27 4,81 1,67 2,82 0,780822 0,829522 Dorsal #146 6,49 5,29 5,06 4,85 2,37 2,64 0,8151 1,090722 Dorsal #147 6,89 5,5 5,38 5,14 2,53 2,97 0,798258 1,070039 Dorsal #148 5,11 4,75 5,39 4,88 2,2 2,7 0,92955 0,973361 Dorsal #149 4,14 4,21 3,69 4,33 1,71 2,61 1,016908 0,972286 Dorsal #150 5,14 3,4 4,32 3,71 2,08 2,53 0,661479 0,916442 Dorsal #151 4,85 4,76 4,98 4,38 1,57 2,31 0,981443 1,086758 Dorsal #152 5,43 4,28 4,22 - - - 0,788214 - Dorsal #153 5,15 5,48 5,15 4,58 - - 1,064078 1,196507 Dorsal #154 4,3 4,45 4,29 4,2 1,74 2,74 1,034884 1,059524 Dorsal #155 5,11 4,16 4,51 4,28 - - 0,81409 0,971963 Dorsal #156 4,84 5,25 4,36 3,44 1,27 2,11 1,084711 1,526163 Dorsal #157 6,77 5,69 5,86 5,18 - 3,05 0,840473 1,098456

Dorsal #158 4,31 5,11 5,61 4,49 2,03 3,47 1,185615 1,138085 Dorsal #159 4,52 4,52 5,07 4,43 2,33 3,41 1 1,020316 Dorsal #160 4,6 4,32 4,03 3,72 2,29 2,88 0,93913 1,16129 Dorsal #161 5,14 4,76 5 4,93 2 2,4 0,92607 0,965517 Dorsal #162 4,62 - 4,33 3,85 2,39 3,09 - - Dorsal #163 4,91 5,91 5,34 4,64 2,06 2,84 1,203666 1,273707 Dorsal #164 4,66 4,02 4,2 3,78 - 2,57 0,862661 1,063492 Dorsal #165 4,89 3,67 4,41 4,28 2,3 3,81 0,750511 0,857477 Dorsal #166 5,01 4,62 5,69 4,53 2,76 3,82 0,922156 1,019868 Dorsal #167 5,19 3,42 4,65 3,85 1,96 2,37 0,65896 0,888312 Dorsal #168 5,16 4,18 5,69 5,12 2,34 3,07 0,810078 0,816406 Dorsal #169 4,77 4,21 4,97 4,34 1,36 2,37 0,8826 0,970046 Dorsal #170 4,98 3,55 4,42 3,81 1,49 2,23 0,712851 0,931759 Dorsal #171 3,82 4,01 4,09 3,68 1,44 1,89 1,049738 1,089674 Dorsal #172 3,29 4,01 3,49 3,32 - - 1,218845 1,207831 Dorsal #173 4,06 4,11 4,04 4,03 1,88 2,01 1,012315 1,019851 Dorsal #174 4,89 4,98 5,4 4,38 1,72 3,05 1,018405 1,136986 Dorsal #175 5,15 4,48 4,54 3,82 - 2,69 0,869903 1,172775 Dorsal #176 4,04 4,86 - 4,24 1,66 2,18 1,20297 1,146226 Dorsal #177 4,57 4,59 4,61 - 4,8 - 1,004376 - Dorsal #178 3,55 4,09 4 3,47 1,62 1,97 1,152113 1,178674 Dorsal #179 4,4 3,49 4,35 3,58 1,87 2,62 0,793182 0,97486 Dorsal #180 3,96 3,66 4,13 3,53 2,1 1,96 0,924242 1,036827

Dorsal #181 4 4,04 4,25 4,01 1,59 2,61 1,01 1,007481 Dorsal #182 4,42 5,03 4,7 4,03 2,16 2,21 1,138009 1,248139 Dorsal #183 3,93 3,28 3,52 2,9 1,89 2,23 0,834606 1,131034 Dorsal #184 4,72 4,59 4,53 4,13 - - 0,972458 1,11138 Dorsal #185 4,93 4 4,59 - 1,42 2,03 0,811359 - Dorsal #186 4,23 3,74 4,33 3,6 - - 0,884161 1,038889 Dorsal #187 3,66 3,56 3,76 3,61 1,62 2,19 0,972678 0,98615 Dorsal #188 3,92 3,05 4,14 3,84 1,69 2,13 0,778061 0,794271 Dorsal #189 4,91 4,09 4,28 3,98 1,95 2,26 0,832994 1,027638 Dorsal #190 6,07 5,96 6,39 5,01 1,86 2,77 0,981878 1,189621 Dorsal #191 5,75 5,24 5,31 4,51 2,12 2,47 0,911304 1,161863 Dorsal #192 5,34 4,88 5,44 5,76 2,17 2,66 0,913858 0,847222 Dorsal #193 4,08 4,33 5,02 4,22 1,61 2,81 1,061275 1,026066 Dorsal #194 5,64 5,05 5,17 4,64 2,35 3,07 0,89539 1,088362 Dorsal #195 5,79 4,37 4,45 4,08 1,93 - 0,75475 1,071078 Dorsal #196 5,23 4,02 4,96 4,38 2,72 2,98 0,768642 0,917808 Dorsal #197 3,36 4,56 5,3 - 1,75 2,55 1,357143 - Dorsal #198 9,69 8,07 9 8,29 2,34 4,46 0,832817 0,973462 Dorsal #199 8,9 10,72 7,52 6,7 2,12 3,4 1,204494 1,6 Dorsal #200 5,32 5,87 5,45 5,24 2 2,89 1,103383 1,120229 Dorsal #201 6,47 7,7 5 3,96 - - 1,190108 1,944444 Dorsal #202 8,94 12,38 - 9,81 3,04 3,66 1,384787 1,261978 Dorsal #203 10,22 10,69 10,83 10,03 2,53 3,03 1,045988 1,065803

Dorsal #204 7,01 10,88 - - - - 1,552068 - Dorsal #205 12,47 11,28 8,91 8,59 2,58 3,93 0,904571 1,313155 Dorsal #206 7,39 8,39 - 7,34 - - 1,135318 1,143052 Dorsal #207 7,71 9,23 - 6,99 - 2,27 1,197147 1,320458 Dorsal #208 7,55 10,52 8,77 6,71 1,59 3,63 1,393377 1,567809 Dorsal #209 7,85 6,32 7,71 6,37 2,34 3,59 0,805096 0,992151 Dorsal #210 9,27 8,72 10,11 - 1,1 2,66 0,940669 - Dorsal #211 7,21 5,41 5,24 4,97 2,4 3,05 0,750347 1,088531 Dorsal #212 8,07 7,37 10,24 - 2,81 4,3 0,913259 - Dorsal #213 7,95 10,83 - - - - 1,362264 - Dorsal #214 8,71 8,33 7,23 6,52 - - 0,956372 1,277607 Dorsal #215 6,91 10,15 9,31 - - - 1,468886 - Dorsal #216 8,76 ------Dorsal #217 5,36 5,1 - 5,7 1,57 2,27 0,951493 0,894737 Dorsal #218 10,73 - - - 2 4,56 - - Dorsal #219 9,17 10,05 - - 1,78 3,46 1,095965 - Dorsal #220 5,52 5,53 5,58 - 1,94 2,61 1,001812 - Dorsal #221 7,46 6,61 6,77 5,28 1,94 3,05 0,886059 1,251894 Dorsal #222 8,34 10,46 10,01 - 2,01 3,81 1,254197 - Dorsal #223 6,13 5,15 - 4,82 - 2,22 0,840131 1,068465 Dorsal #224 6,92 7,33 7,05 6,32 - 3,53 1,059249 1,15981 Dorsal #225 4,39 4,79 3,97 - 1,66 2,57 1,091116 - Dorsal #226 7,78 10,79 - 9,22 2,51 3,38 1,386889 1,170282

Dorsal #227 7,97 10,91 9,51 8,38 1,93 3,51 1,368883 1,301909 Dorsal #228 6,33 5,01 - - 1,76 3 0,791469 - Dorsal #229 5,32 5,85 6,66 5,79 2,27 4,29 1,099624 1,010363 Dorsal #230 7,2 10,29 - 5,9 0,81 2,87 1,429167 1,744068 Dorsal #231 5,14 4,67 4,91 3,79 1,72 1,99 0,90856 1,23219 Dorsal #232 7,2 7,26 - 8,09 2,36 4,02 1,008333 0,897404 Dorsal #233 5,65 5,51 - - 1,92 3,39 0,975221 - Dorsal #234 5,41 5,06 5,5 5 1,65 3,17 0,935305 1,012 Dorsal #235 8,71 7,98 - - 1,86 2,96 0,916188 - Dorsal #236 10,31 9,21 10,52 - - - 0,893307 - Dorsal #237 5,15 3,61 5,34 4,66 2,52 3,34 0,700971 0,774678 Dorsal #238 8,6 8,72 9,35 - 2,15 3,12 1,013953 - Dorsal #239 7,34 7,59 7,18 - 1,86 3,52 1,03406 - Dorsal #240 5,77 5,37 4,98 4,48 1,61 2,91 0,930676 1,198661 Dorsal #241 5,51 5,52 5,42 4,94 2,08 3,21 1,001815 1,117409 Dorsal #242 6,27 - - - 2,57 4,49 - - Dorsal #243 5,56 7,41 6,67 5,89 2,72 3,22 1,332734 1,258065 Dorsal #244 5,57 5,26 5,57 - 2,01 3,21 0,944345 - Dorsal #245 3,11 3,74 4,46 4,28 2,16 3,03 1,202572 0,873832 Dorsal #246 5,31 4,18 4,51 - 2,24 2,74 0,787194 - Dorsal #247 6,34 4,77 5,27 - 1,99 3,37 0,752366 - Dorsal #248 5,08 5,48 4,42 4,15 1,88 2,86 1,07874 1,320482 Dorsal #249 7,55 8,09 6,38 - 0,82 1,68 1,071523 -

Dorsal #250 6,42 6,92 7,33 - 2,38 3,18 1,077882 - Dorsal #251 9,11 7,18 6,15 5,01 2,75 3,64 0,788145 1,433134 Dorsal #252 6,35 5,42 5,46 4,59 1,87 3,24 0,853543 1,180828 Dorsal #253 5,81 6,63 5,71 - 1,16 2,73 1,141136 - Dorsal #254 4,84 4,62 4,66 - 1,13 1,59 0,954545 - Dorsal #255 4,19 4,03 3,86 3,35 1,21 2,19 0,961814 1,202985 Dorsal #256 7,56 6,76 6,03 5,79 1,68 3,15 0,89418 1,16753 Dorsal #257 5,01 5,12 4,59 4,18 - - 1,021956 1,22488 Dorsal #258 7,64 5,81 5,96 5,88 2 3,58 0,760471 0,988095 Dorsal #259 4,8 4,38 4,61 4,23 - - 0,9125 1,035461 Dorsal #260 4,41 4,57 4,89 - 1,31 2,62 1,036281 - Dorsal #261 - 7,34 8,2 - - - - - Dorsal #262 5,98 6,33 6,3 5,26 2 3,1 1,058528 1,203422 Dorsal #263 5,61 6,51 - 4,41 1,44 2,61 1,160428 1,47619 Dorsal #264 7,04 5,73 5,58 4,94 2,02 2,91 0,81392 1,159919 Dorsal #265 6,17 5,74 5,98 - - 2,67 0,930308 - Dorsal #266 4,19 4,36 4,63 4,14 1,64 2,79 1,040573 1,05314 Dorsal #267 6,09 6,56 - 4,77 - - 1,077176 1,375262 Dorsal #268 - 7,09 - 5,81 1,57 3,4 - 1,22031 Dorsal #269 6,63 9,1 - - 1,67 2,26 1,372549 - Dorsal #270 5,42 4,4 - 4,13 1,4 2,7 0,811808 1,065375 Dorsal #271 5,69 6,05 - 4,12 - 2,27 1,063269 1,468447 Dorsal #272 6,72 5,52 5,29 5,08 1,63 3,1 0,821429 1,086614

Dorsal #273 5,53 6,06 4,17 4,19 1,01 2,08 1,095841 1,446301

7.3 Measurements of caudal centra

SPECIME A-P D-V M-L width M-L width Min. Max. D-V height / D-V height / N length height including facets excluding facets neural neural A-P length M-L width canal canal (exluding facets)

Caudal #1 (figured in 9,9 8,14 7,42 7,27 1,71 2,74 0,822222 1,11967 Ekeheien 2016) Caudal 6,21 6,54 - 3,11 - 1,54 1,05314 2,102894 #2 Caudal 6,13 4,82 - 4,81 - 2,51 0,786297 1,002079 #3 Caudal 11,38 6,31 - 5,83 1,76 2,38 0,554482 1,082333 #4 Caudal 10,97 8,16 - 5,62 - - 0,743847 1,451957 #5 Caudal 12,09 8,73 2,16 6,45 - - 0,722084 1,353488 #6 Caudal 10,35 8,34 - 4,65 - - 0,805797 1,793548 #7 Caudal 6,71 6,75 - 4,59 1,64 2,32 1,005961 1,470588

#8 Caudal 8,31 7,76 - 7,09 - 3,14 0,933815 1,094499 #9 Caudal 8,87 6,34 - 4,12 - - 0,714769 1,538835 #10 Caudal 8,29 6,47 - 6,7 - - 0,780458 0,965672 #11 Caudal 12,07 7,25 - 5,8 - - 0,600663 1,25 #12 Caudal 7,18 4,87 - 4,5 2,2 2,87 0,678273 1,082222 #13 Caudal 6,44 4,77 - 3,2 - - 0,740683 1,490625 #14 Caudal 6,59 6,23 - 5,66 - 2,87 0,945372 1,100707 #15 Caudal 7,34 5,48 - 3,81 1,22 1,62 0,746594 1,43832 #16 Caudal 6,81 4,85 - 4,7 1,86 2,47 0,712188 1,031915 #17 Caudal 8,29 4,8 - 2,91 - - 0,579011 1,649485 #18 Caudal 5,49 5,14 - 4,14 - - 0,936248 1,241546 #19

Caudal 14,94 16,59 12,62 - 2,14 3,25 1,110442 - #20 Caudal 13,78 15,94 - 11,72 - 3,01 1,156749 1,360068 #21 Caudal 10,7 10,37 10,06 - - 3,47 0,969159 - #22 Caudal 11 13,16 9,67 8,05 1,72 2,1 1,196364 1,634783 #23 Caudal 9,82 14,3 9,59 8,62 1,22 3,49 1,456212 1,658933 #24 Caudal 9,87 11,4 - 10,64 2,17 2,8 1,155015 1,071429 #25 Caudal 10,84 14,42 - 9,34 1,88 2,72 1,330258 1,543897 #26 Caudal 11,58 14,87 10,36 - - 2,81 1,284111 - #27 Caudal 15,09 18,43 12,72 - 1,91 3,78 1,221339 - #28 Caudal 12,28 15,77 14,58 12,1 1,1 2,83 1,284202 1,303306 #29 Caudal 13,22 14,87 - 8,6 - - 1,124811 1,72907 #30 Caudal 10,75 14,18 - - - 4,15 1,31907 -

#31 Caudal 10,87 10,71 - 8,47 1,34 2,65 0,985281 1,264463 #32 Caudal 10,59 13,36 10,75 - - 3,87 1,261568 - #33 Caudal 7,62 12,31 9,22 9,65 1,49 2,71 1,615486 1,275648 #34 Caudal 14,58 15,33 - - - - 1,05144 - #35 Caudal 10 13,44 8,89 8,22 1,03 3,16 1,344 1,635036 #36 Caudal 9,05 12,41 - 10,01 1,36 2,08 1,371271 1,23976 #37 Caudal 13,72 13,17 - - - - 0,959913 - #38 Caudal 13,32 13,8 - 9,91 - 2,9 1,036036 1,392533 #39 Caudal 13,01 11,82 - 10,36 2,38 3,13 0,908532 1,140927 #40 Caudal 8,92 13,39 - 8,35 1,6 2,32 1,501121 1,603593 #41 Caudal 8,53 11,11 8,47 7,53 2,16 3,1 1,302462 1,475432 #42

Caudal 10,91 12,39 - 8,72 0,88 1,49 1,135655 1,420872 #43 Caudal 10,41 10,99 9,09 - 1,3 1,91 1,055716 - #44 Caudal 10,95 12,81 7,78 - - - 1,169863 - #45 Caudal 12,81 13,04 9,52 - - 2,47 1,017955 - #46 Caudal 10,03 12,13 - 10,19 - 2,85 1,209372 1,190383 #47 Caudal 7,85 9,92 6,91 6,38 1,23 3,15 1,263694 1,554859 #48 Caudal 11,88 12,59 - 7,87 1,17 2,78 1,059764 1,599746 #49 Caudal 8,14 8,97 6,91 6,41 1,73 2,86 1,101966 1,399376 #50 Caudal 9,5 10,98 7,38 - - - 1,155789 - #51 Caudal 9,42 9,6 - 9,76 4,44 4,86 1,019108 0,983607 #52 Caudal 9,56 10,59 - 7,65 - - 1,107741 1,384314 #53 Caudal 10,87 11,01 - 8,79 - 2,23 1,012879 1,25256

#54 Caudal 9,98 11,06 - 9,59 1,7 2,19 1,108216 1,153285 #55 Caudal 12,72 12,92 - 9,23 - 2,55 1,015723 1,399783 #56 Caudal 9,98 10,57 8,87 7,64 - - 1,059118 1,383508 #57 Caudal 8,54 9,91 - 6,76 - - 1,160422 1,465976 #58 Caudal 11,07 10,91 - 8,59 1,23 1,7 0,985547 1,270081 #59 Caudal 11,09 14,56 - 7,66 0,7 2,25 1,312894 1,900783 #60 Caudal 10,39 10,16 6,72 - 0,63 2,31 0,977863 - #61 Caudal 10,53 - - - 0,74 2,49 - - #62 Caudal 10,05 9,78 8,36 7,4 0,94 2,18 0,973134 1,321622 #63 Caudal 6,23 6,7 6,79 6,1 - 2,83 1,075441 1,098361 #64 Caudal 7,12 7,34 - 4,63 1,2 1,59 1,030899 1,585313 #65

Caudal 7,23 9,33 6,32 5,23 - - 1,290456 1,783939 #66 Caudal - 14,11 ------#67 Caudal 9,64 9,61 - 8,54 1,36 2,16 0,996888 1,125293 #68 Caudal 7,09 11,19 8,06 6,66 2,18 2,58 1,578279 1,68018 #69 Caudal 6,69 8,68 - 6,04 - 1,58 1,297459 1,437086 #70 Caudal 9,81 11,92 - 6,75 - - 1,215087 1,765926 #71 Caudal 8,27 8,31 - 4,96 0,74 1,7 1,004837 1,675403 #72 Caudal 7,89 9,12 - 6,53 - - 1,155894 1,396631 #73 Caudal 6,43 10,06 - 6,59 - - 1,564541 1,526555 #74 Caudal 6,8 8,06 6,74 5,63 1,22 2,23 1,185294 1,431616 #75 Caudal 6,51 8,86 - 9,41 2,69 4,34 1,360983 0,941552 #76 Caudal 7,53 7,73 6,51 5,55 1,5 2,22 1,02656 1,392793

#77 Caudal 9,34 7,36 - 8,36 1,9 3,96 0,788009 0,880383 #78 Caudal 7,62 7,07 - 6,94 1,88 3,36 0,927822 1,018732 #79 Caudal 5,68 5,72 - 5,24 1,57 2,81 1,007042 1,091603 #80 Caudal 7,06 6,01 - 5,99 - 2,83 0,851275 1,003339 #81 Caudal 7,11 5,34 - 4,29 - - 0,751055 1,244755 #82 Caudal 6,9 5,89 - 6,33 2,27 2,73 0,853623 0,93049 #83 Caudal 8,65 9,46 - 5,11 - 1,39 1,093642 1,851272 #84 Caudal 6,9 7,33 7,43 6,86 2,44 3,18 1,062319 1,068513 #85 Caudal 6,13 6,51 - 5,19 - 1,88 1,06199 1,254335 #86 Caudal 7,83 7,34 - 6,55 1,71 3,07 0,93742 1,120611 #87 Caudal 7,06 7,4 - - 1,16 2,7 1,048159 - #88

Caudal 4,83 5,08 - 4,68 1,71 2,85 1,05176 1,08547 #89 Caudal 9,22 9,4 6,45 - 1,66 3,02 1,019523 - #90 Caudal 7 6,99 - 5,05 1,2 2,26 0,998571 1,384158 #91 Caudal 7,12 8,07 - 5,48 1,73 2,08 1,133427 1,472628 #92 Caudal 7,16 8,05 - 5,52 1,58 2,29 1,124302 1,458333 #93 Caudal 6,53 6,7 - 4,57 - 1,4 1,026034 1,466083 #94 Caudal 8,85 6,86 - - 2,04 3,01 0,775141 - #95 Caudal 6,31 6,52 6,32 5,45 2,38 3,1 1,033281 1,19633 #96 Caudal 6,79 8,24 4,96 4,09 1,4 2,16 1,213549 2,01467 #97 Caudal 8,48 7,08 4,67 4,53 0,84 1,77 0,834906 1,562914 #98 Caudal 8,29 7,68 8,27 - 2,21 3,14 0,926417 - #99 Caudal 7,12 8 - 7,06 - 3,04 1,123596 1,133144

#100 Caudal 5,56 4,89 5,23 5,03 - - 0,879496 0,972167 #101 Caudal 7,51 7,43 4,31 4,14 - - 0,989348 1,794686 #102 Caudal 8,16 7,57 - - 1,25 1,83 0,927696 - #103 Caudal 5,72 4,91 5,42 5,14 2,07 2,48 0,858392 0,955253 #104 Caudal 5,37 5,96 - 3,4 0,99 2,09 1,10987 1,752941 #105 Caudal 6,62 6,53 - 4,58 0,84 2,04 0,986405 1,425764 #106 Caudal 6,49 6,33 - 5,82 1,35 2,71 0,975347 1,087629 #107 Caudal 6,94 6,99 - 4,99 1,22 2,26 1,007205 1,400802 #108 Caudal 7,01 7,83 6,48 5,43 - 2,71 1,116976 1,441989 #109 Caudal 7,57 6,46 - 4,42 1,23 1,63 0,853369 1,461538 #110 Caudal 7,89 6,59 5,23 4,6 - 2,16 0,835234 1,432609 #111

Caudal 7,44 8,33 7,2 7,08 - - 1,119624 1,176554 #112 Caudal 7,02 7,8 7,42 6,87 1,66 2,72 1,111111 1,135371 #113 Caudal 7,59 8,72 6,14 5,02 1,76 2,59 1,14888 1,737052 #114 Caudal 6,25 6,1 5,8 5,34 2,16 3,07 0,976 1,142322 #115 Caudal 6,73 6,21 - 5,46 - - 0,922734 1,137363 #116 Caudal 6 7,64 6,86 6,24 2,5 2,51 1,273333 1,224359 #117 Caudal 8,83 10,16 8,56 6,45 2,28 2,89 1,150623 1,575194 #118 Caudal 7,9 9,24 6,53 6,23 - 2,25 1,16962 1,483146 #119 Caudal 8,91 8,09 - - - - 0,907969 - #120 Caudal 5,34 4,29 - - 1,31 2,4 0,803371 - #121 Caudal 7,26 6,6 6,01 5,31 2,07 2,51 0,909091 1,242938 #122 Caudal 6,36 6,61 6,22 4,97 - - 1,039308 1,32998

#123 Caudal 5,83 5,33 4,7 4,37 - - 0,914237 1,21968 #124 Caudal 6,79 5,57 5,9 4,97 2,08 2,56 0,820324 1,120724 #125 Caudal 7,11 5,85 5,8 5,25 0,87 1,66 0,822785 1,114286 #126 Caudal 8,94 7,62 5,95 - - - 0,852349 - #127 Caudal 6,39 6,18 5,46 4,7 1,73 3,09 0,967136 1,314894 #128 Caudal 4,02 4,51 4,49 4,14 1,4 1,72 1,121891 1,089372 #129 Caudal 6,49 5,98 - 5,21 1,7 2,78 0,921418 1,147793 #130 Caudal 7,13 7,34 - 3,79 - - 1,029453 1,936675 #131 Caudal 7,28 5,94 - 5,41 - 2,53 0,815934 1,097967 #132 Caudal 7,54 7,47 - 5,43 1,19 2,1 0,990716 1,375691 #133 Caudal 5,78 5,83 - 4,88 1,5 2,11 1,008651 1,194672 #134

Caudal 5,81 5,51 4,82 4,22 2,02 1,9 0,948365 1,305687 #135 Caudal 6,99 6,84 7,37 - 2,07 3,31 0,978541 - #136 Caudal 6,37 6,14 - - 1,86 2,14 0,963893 - #137 Caudal 4,52 4,01 3,6 2,76 1,39 1,39 0,887168 1,452899 #138 Caudal 5,87 4,46 5,04 5,16 2,38 3,11 0,759796 0,864341 #139 Caudal 5,83 6,26 - 4,89 1,06 2,36 1,073756 1,280164 #140 Caudal 6,61 5,93 - 5,08 1,7 2,04 0,897126 1,167323 #141 Caudal 4,88 - - - 1,72 3,06 - - #142 Caudal 5,56 5,4 - 4,94 1,47 1,96 0,971223 1,093117 #143 Caudal 7,43 6,06 - 5,96 1,26 - 0,815612 1,016779 #144 Caudal 7,58 6,11 - 4,48 0,78 - 0,806069 1,363839 #145 Caudal 5,21 5,27 - 3,24 0,63 0,89 1,011516 1,626543

#146 Caudal 5,71 6,08 - 4,03 - - 1,064799 1,508685 #147 Caudal 5,54 4,82 - 3,87 1,69 2,49 0,870036 1,245478 #148 Caudal 7,74 4,99 - 5,48 2,59 2,83 0,644703 0,910584 #149 Caudal 4,52 4,72 4,34 4,03 - 2,4 1,044248 1,171216 #150 Caudal 6,33 5,92 - 4,91 - 1,77 0,935229 1,205703 #151 Caudal 6,82 5,18 - 3,66 1,1 1,51 0,759531 1,415301 #152 Caudal 5,22 5,53 4,2 3,58 - 1,64 1,059387 1,544693 #153 Caudal - 5,74 5,63 - 2,03 2,82 - - #154 Caudal 5,18 4,86 - 3,56 - 1,33 0,938224 1,365169 #155 Caudal 5,53 4,6 - 3,86 1,04 1,43 0,831826 1,19171 #156 Caudal 6,32 4,97 - 4,11 1 1,39 0,786392 1,209246 #157

Caudal 5,86 5,91 - - - 2,87 1,008532 - #158 Caudal 4,8 4,44 4,8 - 1,81 2,21 0,925 - #159 Caudal 5,63 5,34 4,16 3,72 1,18 1,92 0,94849 1,435484 #160 Caudal 4,92 4,36 4,01 3,72 1,94 2,79 0,886179 1,172043 #161 Caudal 4,82 4,97 4,89 - 1,55 2,49 1,03112 - #162 Caudal 4,24 5,49 4,42 4,2 - - 1,294811 1,307143 #163 Caudal 4,52 5,09 - 4,43 1,95 2,75 1,126106 1,148984 #164 Caudal 3,25 2,87 - 2,66 1,57 2,27 0,883077 1,078947 #165 Caudal 4,03 - - - 1,51 2,18 - - #166 Caudal 4,46 5,19 - - - - 1,163677 - #167 Caudal 4,1 3,86 3,6 2,42 1,33 2,19 0,941463 1,595041 #168 Caudal 4,01 5,33 - 3,46 1,37 1,63 1,329177 1,540462

#169 Caudal 4,87 4,21 4,22 3,84 1,21 1,98 0,864476 1,096354 #170 Caudal 3,85 3,07 3,44 3,72 1,69 2,83 0,797403 0,825269 #171 Caudal 5,52 4,22 - 3,95 - 1,7 0,764493 1,068354 #172 Caudal 3,93 3,74 - 3,18 - - 0,951654 1,176101 #173 Caudal 4,7 5,23 - 4,28 - - 1,112766 1,221963 #174 Caudal 4,92 4,68 - 3,49 - 1,42 0,95122 1,340974 #175 Caudal 4,25 4,53 - 3,85 - 0,98 1,065882 1,176623 #176 Caudal 6,04 5,58 5,05 4,42 - 1,66 0,923841 1,262443 #177 Caudal 4,85 4,77 - 3,17 0,76 1,27 0,983505 1,504732 #178 Caudal 5,13 6,33 5,39 4,29 - 2,36 1,233918 1,475524 #179 Caudal 6,09 6,23 4,24 3,26 - 1,87 1,022989 1,911043 #180

Caudal 5,46 - - - 1,68 2,33 - - #181 Caudal 6,35 - - - 2,14 2,7 - - #182