Morphology, Phylogeny and Taxonomy of Osteolepiform Fish

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, Lukševiès & 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 Clément, 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, Clément & Cloutier, 2007 480 Genus Criptolepis Worobjeva, 1975c 481 Acknowledgements 481 References 482 Tables 491 Appendix Abbreviations used in illustrations and tables 506