Morphology, phylogeny and taxonomy of osteolepiform fish

Content: Introduction  1   General taxonomy  2       Crossoptgerygii    and    Rhipidistia    2    Osteolepiform subdivisions  3    Terminology  4    Cranial roof  4    Endocranium  13    Dermal bones in mouth roof  13    Lower jaw  14    Operculo-gular bones 15    Upper Palaeozoic fossil locality in the Oslo Region  16    Stratigraphy  16    Descriptions  18    Material, methods and repository  18    Genus Askerichthys n gen  20    Askerichthys heintzi n sp  20    Genus Megalichthys Agassiz, 1835  62    Megalichthys cf M hibberti Agassiz, 1835 62    Megalichthys pygmaeus Tranquair, 1879  97    Megalichthys syndentolaminaris n sp  99    Genus Latvius Jarvik, 1948 100    Latvius grewingki (Gross, 1933) 101    Latvius deckerti Jensen, 1966 114    Latvius sp Jensen, 1966 121    Latvius cf L niger Jensen, 1973 128    Genus Osteolepis Agassiz, 1835 130    Osteolepis macrolepidotus Agassiz, 1835 131    Genus Gyroptychius McCoy, 1848 131    Gyroptychius milleri (Jarvik, 1948) 131    Gyroptychius groenlandicus Jarvik, 1950a 141    Morphologic comparisons and discussions 160    Fronto-ethmoidal shield 160    General shape 160    Interpremaxilla 162    Composition of naso-rostro-premaxillary complex 162    Shape of upper mouth margin 165    Anterior palatal (premaxillary and rostral) teeth and palatal processes 166    Defi nitions and occurrences of morphotypes of anterior palatal teeth 166    Tooth replacement and evolutionary relationship between the anterior palatal dental morphotypes 167    Number of premaxillary teeth 169    Systematic significance of anterior palatal teeth 170    Anterior palatal processes 171    Postrostrals 172    Variation and trends in postrostral pattern 172    Taxonomic significance of postrostral pattern 176    Nasals 178    Number of nasal bones 178    Positions of the bones in the nasal series 178    Circumnarial dermal bones and supraorbitals 180    Variation in eusthenopterids 180    Reconstructing the circumnarial pattern in Osteolepis macrolepidotus 186    Reconstructing the pattern of supraorbitals in Osteolepis macrolepidotus 188    Circumnarial and supraorbital pattern in other Devonian osteolepiforms 189    Homologizations of circumnarial bones in Megalichthys hibberti, Ectosteorhachis, Askerichthys and Cladarosymblema 191    Supraorbito-tectal series of panderichthyids 196    Frontals and dermosphenotics 197    Shape and composition of frontals 197    Shape, positions and extension of dermosphenotic bones 199    Fenestrae 199    Position of nasal fenestra 199    Shape of nasal fenestra 200    Processus dermintermedius 201    Tubercles in nasal fenestra 202    Presence or absence of pineal openings 202    Position of pineal foramen 203    Shape of pineal openings 204    Size of pineal fenestra and presence of pineal plates 204    Sensory canals 204    Pitlines 205    Parietal shield 206    Relative lengths of fronto-ethmoidal and parietal shields 206    Shape of parietal shield 207    Proportions 207    Protruding posterior margin 209    Position of spiracular incision 212    Relative length of the spiracular incision 213    Parietals 214    Shape of parietals 214    Parietal structures 214    Intertemporals 215    Shape of interpemporal 215    Anterior intertemporal margin and process in post-Devonian taxa 216    Anterior intertemporal processes in Devonian forms 222    On the function of the intracranial joint 223    Lateral shelf of intertemporal 223    Ventral surface of intertemporal 224    Supratemporals 228    Shape 228    Ventral surface and lateral margin 228    Spiracular structures 231    Extension of the spiracular opening 231    Types of spiracular openings 232    Possible muscle insertions around the spiraculum 233    Extratemporal (= postspiraculars) 236    Sensory canals 236    Course of sensory canal 236    Position of canal openings 237    Pitlines 238    Extrascapulars238    Dermal palatal bones 239    Vomers 239    Review of taxa with known vomers 239    Transverse tusk positions on anterior vomers 243    Configuration of anterior vomers 244    Extensions and proportions of the posterior vomer 245    Dental lamina and teeth 245    Intervomerine Canals 246    Evolution of the vomers 247    Parasphenoid 248    Division of the parasphenoid 248    Paraspenoid dental plate 248    Buccohypophysial foramen 250    Pars anterior of parasphenoid 250    Parasphenoid shelves and processi ascendens 250    Foramina on the shelf 253    Acrochordal depressions, additional dermal bones and basicranial muscles 254    Occurrence of acrochordal depressions 254    Function of acrochordal depressions 255    Endocranium 258    Ethmosphenoid 258    Proportions of ethmosphenoid 258    Subethmoidal fossae 258    Nasobasal canal and palatonasal canal 261    Internal structures of nasal capsule 261    Postnasal wall 263    Orbitosphenoid wall of eusthenopterids 268    Comparing orbitosphenoid region of Ectosteorhachis foordi with other cyclolepidoids than eusthenopterids 271    Orbitosphenoid in Osteolepidoidei and other forms 273    Systematic significance of orbitosphenoid structure 277    Posterior end of orbitosphenoid 277    Otico-occipital 278    Cheek plate 280    Maxilla 280    Shape 280    Ventral margin and tooth distribution on maxilla  282    Postorbital and squamosal 283    Lachrymal 285    Jugal 285    Shape 285    Contact with the orbit 285    Quadratojugal 287    Lower jaw (= mandible) 287    Shape 287    Proportions 287    Anterior notch 288    Antero-dorsal bulb 288    Dorsal margin 288    Positions of dental margin and glenoid notch 290    Retroarticular process 292    External structures 292    Dentary/Infradentary suture 292    Inter-infradentary sutures 294    Dorsal cosmine notch, cosmine corners and postero-dorsal bone margin 295    Horizontal pitline 298    Vertical pitline of infradentary 2 300    Sensory canal 300    Canal course 301    Configuration of canals 301    Dentary 302    Dentary teeth 302    Dentary shelf and dental fossa 307    Coronoids 307    Number of coronoid bones and tusks 307    Replacement of coronoid tusks 312    Relative size of coronoid tusks 313    Relative positions of coronoid tusks 315    Coronoid dental ridge 317    Intercoronoid fossae 321    Anterior mandibular fossa 322    Prearticular 322    Presence of a pars anterior of the prearticular 322    Anteriad extension and configuration of pars anterior of the prearticular 323    Course of the pars anterior of the prearticular 329    Anterior extension of prearticular dental plate 330    Shape of dental plate 331    Prearticular dental plate configuration and teeth 332    Postero-ventral depression 332    Posterior part of prearticular 333    Parasymphyseal dental plate and adsymphysial fossa 333    Occurrence of Parasymphyseal dental plate 333    Shape of Parasymphyseal dental plate 334    Relations of Parasymphyseal dental plate to other bones 334    Adsymphysial fossa 338    Infradentaries 341    Infradentary surfaces 341    Posterior extension of infradentaries 341    Meckelian bone 342    Pars mentomandibularis 342    Ventral exposures 342    Pars articularis 342    Foramina 343    Sensory canal foramina 343    Foramina for nerves and vessels 344    Sensory canal pore patterns 350    Distribution patterns of sensory pores 350    Pore distribution as an age indicator 350    Evolution of pore dispersion 353    Taxonomic significance of pore number and distribution 355    Size and types of sensory pits  357    Operculo-gular complex 357    Median gular 357    Principal gulars 360    Submandibulars 362    Opercular and subopercular 365    Shoulder girdle  367    Scapulocoracoid 367    Dermal shoulder girdle 368    Fins  369    Caudal fin 369    Position of fins 370    Scales, body proportions and vertebrae 370    Scales 370    Scale distribution 370    Scale morphology 371    Body proportions 371    Vertebrae 371    Phylogeny and taxonomy of osteolepiforms 372    Taxonomic concepts and principles 372    Characters 372    Quantitative characters 372    Primitive and derived characters, convergence, parallelism and homoplasy 372    Sufficient, necessary, indicative,single and combined characters 375    Diagnoses 376    A phylogenetic model 377    A systematic model 381    Order Osteolepiformes Berg, 1937 381    Suborder Osteolepidoidei Moy-Thomas & Miles, 1971 382    Family Thursiidae n fam  383    Genus Thursius Traquair, 1888  384    Family Osteolepididae Cope, 1889 388    Subfamily Glyptopominae Goodrich, 1909 389    Genus Glyptopomus Agassiz, 1844 390    Genus Megistolepis Obruchev, 1955 392    Genus Shirolepis Vorobyeva, 1977a 393    Genus Greiserolepis Vorobyeva, 1977a 394    Subfamily Osteolepidinae n subfam 396    Genus Osteolepis Agassiz, 1835 396    Genus Latvius Jarvik, 1948 397    Genus Gogonasus Long, 1985b 400    Genus Geptolepis Vorobyeva & Lebedev, 1986a 403    Genus Peregrina Vorobyeva & Lebedev, 1986b 404    Family Megalichthyidae Hay, 1902 406    Subfamily Ectosteorhachinae n subfam 412    Genus Ectosteorhachis Cope, 1880 412    Subfamily Megalichthyinae n subfam or Cope, 1940 415    Genus Cladarosymblema Fox, Cambell, Barwick & Long, 1995 415    Genus Megalichthys Agassiz, 1835 415    Subfamily Askerichthyinae n subfam 419    Genus Askerichthys n gen 419    Suborder Cyclolepidoidei n suborder 420    Superfamily Eopodoidea n superfam 420    Family Gyroptychiidae Berg, 1958 Berg 1940 422    Genus Gyroptychius McCoy, 1848 422    Family Panderichthyidae Vorobyeva & Lyarskaya, 1968 429    Subfamily Panderichthyinae n subfam 432    Genus Panderichthys Gross, 1941 432    Genus Livoniana Ahlberg, Luk  evies & Lebedev, 2000 435    Subfamily Elpistosteginae n subfam 435    Genus Elpistostege Westoll, 1938  436    Genus Tiktaalik Daeschler, Shubin & Jenkins, 2006  436    Family Chrysolepididae n fam 438    Genus Chrysolepis Lebelev, 1983 438    Family Eusthenopteridae Berg, 1955 440    Genus Tristichopterus Egerton, 1861 445    Genus Eusthenopteron Whiteaves, 1881 447    Genus Eusthenodon Jarvik, 1952 448    Genus Platycephalichthys Vorobyeva, 1959 449    Genus Jarvikina Vorobyeva, 1977a 452    Genus Marsdenichthys Long, 1985a 453    Genus Spodichthys Jarvik, 1985 455    Genus Notorhizodon Young, Long, & Ritchie, 1992 456    Genus Mandageria Johanson & Ahlberg, 1997 457    Genus Cabonnichthys Ahlberg & Johanson, 1997 458    Genus Heddleichthys Snitting, 2008b 460    Genus Langlieria Clement, Snitting & Ahlberg, 2008  462    Superfamily Parapodoidea n superfam 463    Family Medoevididae n fam 463    Genus Medoevia Lebedev, 1995 463    Family Canowindridae Young, Long & Ritchie, 1992 464    Genus Canowindra Th omson, 1973 465    Genus Beelarongia Long, 1987 466    Genus Koharalepis Young, Long & Ritchie, 1992 467    Superfamily Rhizodontoidea n superfam 468    Osteolepiformes subord indet 468    Family Lamprotolepididae Vorobyeva, 1977a 468    Genus Lamprotolepis Vorobyeva, 1977a  468    Osteolepiformes subord & fam indet 470    Genus Litoptychius Denison, 1951 470    Genus Lohsania Thomson & Vaughn, 1968 471    Genus Sterropterygion Thomson, 1972 472    Genus Megapomus Vorobyeva, 1977a 472    Genus Thysanolepis Vorobyeva, 1977a 474    Genus Viluichthys Vorobyeva, 1977a  475    Genus Mahalalepis Young, Long & Ritchie, 1992 476    Genus Platyethmoidea Young, Long & Ritchie, 1992 478    Genus Vorobjevaia Young, Long & Ritchie, 1992 479    Genus Sengoerichthys Janvier, Clement & Cloutier, 2007 480    Genus Criptolepis Worobjeva, 1975c 481    Acknowledgements 481    References 482    Tables 491    Appendix Abbreviations used in illustrations and tables 506