Morphology, Phylogeny and Taxonomy of Osteolepiform Fish

Ulf J. Borgen is the editor of Morphology, Phylogeny and Taxonomy of Osteolepiform Fish, published by Wiley.Hans A. Nakrem is the editor of Morphology, Phylogeny and Taxonomy of Osteolepiform Fish, published by Wiley.

• Introduction  1 General taxonomy  2‘Crossoptgerygii’ and ‘Rhipidistia’ 2Osteolepiform subdivisions  3Terminology  4Cranial roof  4Endocranium  13Dermal bones in mouth roof  13Lower jaw  14Operculo-gular bones 15Upper Palaeozoic fossil locality in the Oslo Region  16Stratigraphy  16Descriptions  18Material, methods and repository  18Genus Askerichthys n gen  20Askerichthys heintzi n sp  20Genus Megalichthys Agassiz, 1835  62Megalichthys cf M hibberti Agassiz, 1835 62Megalichthys pygmaeus Tranquair, 1879  97Megalichthys syndentolaminaris n sp  99Genus Latvius Jarvik, 1948 100Latvius grewingki (Gross, 1933) 101Latvius deckerti Jensen, 1966 114Latvius sp Jensen, 1966 121Latvius cf L niger Jensen, 1973 128Genus Osteolepis Agassiz, 1835 130Osteolepis macrolepidotus Agassiz, 1835 131Genus Gyroptychius McCoy, 1848 131Gyroptychius milleri (Jarvik, 1948) 131Gyroptychius groenlandicus Jarvik, 1950a 141Morphologic comparisons and discussions 160Fronto-ethmoidal shield 160General shape 160Interpremaxilla 162Composition of naso-rostro-premaxillary complex 162Shape of upper mouth margin 165Anterior palatal (premaxillary and rostral) teeth and palatal processes 166Defi nitions and occurrences of morphotypes of anterior palatal teeth 166Tooth replacement and evolutionary relationship between the anterior palatal dental morphotypes 167Number of premaxillary teeth 169Systematic significance of anterior palatal teeth 170Anterior palatal processes 171Postrostrals 172Variation and trends in postrostral pattern 172Taxonomic significance of postrostral pattern 176Nasals 178Number of nasal bones 178Positions of the bones in the nasal series 178Circumnarial dermal bones and supraorbitals 180Variation in eusthenopterids 180Reconstructing the circumnarial pattern in Osteolepis macrolepidotus 186Reconstructing the pattern of supraorbitals in Osteolepis macrolepidotus 188Circumnarial and supraorbital pattern in other Devonian osteolepiforms 189Homologizations of circumnarial bones in Megalichthys hibberti, Ectosteorhachis, Askerichthys and Cladarosymblema 191Supraorbito-tectal series of panderichthyids 196Frontals and dermosphenotics 197Shape and composition of frontals 197Shape, positions and extension of dermosphenotic bones 199Fenestrae 199Position of nasal fenestra 199Shape of nasal fenestra 200Processus dermintermedius 201Tubercles in nasal fenestra 202Presence or absence of pineal openings 202Position of pineal foramen 203Shape of pineal openings 204Size of pineal fenestra and presence of pineal plates 204Sensory canals 204Pitlines 205Parietal shield 206Relative lengths of fronto-ethmoidal and parietal shields 206Shape of parietal shield 207Proportions 207Protruding posterior margin 209Position of spiracular incision 212Relative length of the spiracular incision 213Parietals 214Shape of parietals 214Parietal structures 214Intertemporals 215Shape of interpemporal 215Anterior intertemporal margin and process in post-Devonian taxa 216Anterior intertemporal processes in Devonian forms 222On the function of the intracranial joint 223Lateral shelf of intertemporal 223Ventral surface of intertemporal 224Supratemporals 228Shape 228Ventral surface and lateral margin 228Spiracular structures 231Extension of the spiracular opening 231Types of spiracular openings 232Possible muscle insertions around the spiraculum 233Extratemporal (= postspiraculars) 236Sensory canals 236Course of sensory canal 236Position of canal openings 237Pitlines 238Extrascapulars238Dermal palatal bones 239Vomers 239Review of taxa with known vomers 239Transverse tusk positions on anterior vomers 243Configuration of anterior vomers 244Extensions and proportions of the posterior vomer 245Dental lamina and teeth 245Intervomerine Canals 246Evolution of the vomers 247Parasphenoid 248Division of the parasphenoid 248Paraspenoid dental plate 248Buccohypophysial foramen 250Pars anterior of parasphenoid 250Parasphenoid shelves and processi ascendens 250Foramina on the shelf 253Acrochordal depressions, additional dermal bones and basicranial muscles 254Occurrence of acrochordal depressions 254Function of acrochordal depressions 255Endocranium 258Ethmosphenoid 258Proportions of ethmosphenoid 258Subethmoidal fossae 258Nasobasal canal and palatonasal canal 261Internal structures of nasal capsule 261Postnasal wall 263Orbitosphenoid wall of eusthenopterids 268Comparing orbitosphenoid region of Ectosteorhachis foordi with other cyclolepidoids than eusthenopterids 271Orbitosphenoid in Osteolepidoidei and other forms 273Systematic significance of orbitosphenoid structure 277Posterior end of orbitosphenoid 277Otico-occipital 278Cheek plate 280Maxilla 280Shape 280Ventral margin and tooth distribution on maxilla  282Postorbital and squamosal 283Lachrymal 285Jugal 285Shape 285Contact with the orbit 285Quadratojugal 287Lower jaw (= mandible) 287Shape 287Proportions 287Anterior notch 288Antero-dorsal bulb 288Dorsal margin 288Positions of dental margin and glenoid notch 290Retroarticular process 292External structures 292Dentary/Infradentary suture 292Inter-infradentary sutures 294Dorsal cosmine notch, cosmine corners and postero-dorsal bone margin 295Horizontal pitline 298Vertical pitline of infradentary 2 300Sensory canal 300Canal course 301Configuration of canals 301Dentary 302Dentary teeth 302Dentary shelf and dental fossa 307Coronoids 307Number of coronoid bones and tusks 307Replacement of coronoid tusks 312Relative size of coronoid tusks 313Relative positions of coronoid tusks 315Coronoid dental ridge 317Intercoronoid fossae 321Anterior mandibular fossa 322Prearticular 322Presence of a pars anterior of the prearticular 322Anteriad extension and configuration of pars anterior of the prearticular 323Course of the pars anterior of the prearticular 329Anterior extension of prearticular dental plate 330Shape of dental plate 331Prearticular dental plate configuration and teeth 332Postero-ventral depression 332Posterior part of prearticular 333Parasymphyseal dental plate and adsymphysial fossa 333Occurrence of Parasymphyseal dental plate 333Shape of Parasymphyseal dental plate 334Relations of Parasymphyseal dental plate to other bones 334Adsymphysial fossa 338Infradentaries 341Infradentary surfaces 341Posterior extension of infradentaries 341Meckelian bone 342Pars mentomandibularis 342Ventral exposures 342Pars articularis 342Foramina 343Sensory canal foramina 343Foramina for nerves and vessels 344Sensory canal pore patterns 350Distribution patterns of sensory pores 350Pore distribution as an age indicator 350Evolution of pore dispersion 353Taxonomic significance of pore number and distribution 355Size and types of sensory pits  357Operculo-gular complex 357Median gular 357Principal gulars 360Submandibulars 362Opercular and subopercular 365Shoulder girdle  367Scapulocoracoid 367Dermal shoulder girdle 368Fins  369Caudal fin 369Position of fins 370Scales, body proportions and vertebrae 370Scales 370Scale distribution 370Scale morphology 371Body proportions 371Vertebrae 371Phylogeny and taxonomy of osteolepiforms 372Taxonomic concepts and principles 372Characters 372Quantitative characters 372Primitive and derived characters, convergence, parallelism and homoplasy 372Sufficient, necessary, indicative,single and combined characters 375Diagnoses 376A phylogenetic model 377A systematic model 381Order Osteolepiformes Berg, 1937 381Suborder Osteolepidoidei Moy-Thomas & Miles, 1971 382Family Thursiidae n fam  383Genus Thursius Traquair, 1888  384Family Osteolepididae Cope, 1889 388Subfamily Glyptopominae Goodrich, 1909 389Genus Glyptopomus Agassiz, 1844 390Genus Megistolepis Obruchev, 1955 392Genus Shirolepis Vorobyeva, 1977a 393Genus Greiserolepis Vorobyeva, 1977a 394Subfamily Osteolepidinae n subfam 396Genus Osteolepis Agassiz, 1835 396Genus Latvius Jarvik, 1948 397Genus Gogonasus Long, 1985b 400Genus Geptolepis Vorobyeva & Lebedev, 1986a 403Genus Peregrina Vorobyeva & Lebedev, 1986b 404Family Megalichthyidae Hay, 1902 406Subfamily Ectosteorhachinae n subfam 412Genus Ectosteorhachis Cope, 1880 412Subfamily Megalichthyinae n subfam or Cope, 1940 415Genus Cladarosymblema Fox, Cambell, Barwick & Long, 1995 415Genus Megalichthys Agassiz, 1835 415Subfamily Askerichthyinae n subfam 419Genus Askerichthys n gen 419Suborder Cyclolepidoidei n suborder 420Superfamily Eopodoidea n superfam 420Family Gyroptychiidae Berg, 1958 Berg 1940 422Genus Gyroptychius McCoy, 1848 422Family Panderichthyidae Vorobyeva & Lyarskaya, 1968 429Subfamily Panderichthyinae n subfam 432Genus Panderichthys Gross, 1941 432Genus Livoniana Ahlberg, Lukševiès & Lebedev, 2000 435Subfamily Elpistosteginae n subfam 435Genus Elpistostege Westoll, 1938  436Genus Tiktaalik Daeschler, Shubin & Jenkins, 2006  436Family Chrysolepididae n fam 438Genus Chrysolepis Lebelev, 1983 438Family Eusthenopteridae Berg, 1955 440Genus Tristichopterus Egerton, 1861 445Genus Eusthenopteron Whiteaves, 1881 447Genus Eusthenodon Jarvik, 1952 448Genus Platycephalichthys Vorobyeva, 1959 449Genus Jarvikina Vorobyeva, 1977a 452Genus Marsdenichthys Long, 1985a 453Genus Spodichthys Jarvik, 1985 455Genus Notorhizodon Young, Long, & Ritchie, 1992 456Genus Mandageria Johanson & Ahlberg, 1997 457Genus Cabonnichthys Ahlberg & Johanson, 1997 458Genus Heddleichthys Snitting, 2008b 460Genus Langlieria Clément, Snitting & Ahlberg, 2008  462Superfamily Parapodoidea n superfam 463Family Medoevididae n fam 463Genus Medoevia Lebedev, 1995 463Family Canowindridae Young, Long & Ritchie, 1992 464Genus Canowindra Th omson, 1973 465Genus Beelarongia Long, 1987 466Genus Koharalepis Young, Long & Ritchie, 1992 467Superfamily Rhizodontoidea n superfam 468Osteolepiformes subord indet 468Family Lamprotolepididae Vorobyeva, 1977a 468Genus Lamprotolepis Vorobyeva, 1977a  468Osteolepiformes subord & fam indet 470Genus Litoptychius Denison, 1951 470Genus Lohsania Thomson & Vaughn, 1968 471Genus Sterropterygion Thomson, 1972 472Genus Megapomus Vorobyeva, 1977a 472Genus Thysanolepis Vorobyeva, 1977a 474Genus Viluichthys Vorobyeva, 1977a  475Genus Mahalalepis Young, Long & Ritchie, 1992 476Genus Platyethmoidea Young, Long & Ritchie, 1992 478Genus Vorobjevaia Young, Long & Ritchie, 1992 479Genus Sengoerichthys Janvier, Clément & Cloutier, 2007 480Genus Criptolepis Worobjeva, 1975c 481Acknowledgements 481References 482Tables 491Appendix Abbreviations used in illustrations and tables 506