Description
Book SynopsisA discussion and description of prehistoric fish within an international series Material of six osteolepiform genera is described in
Morphology, Phylogeny and Taxonomy of Osteolepiform Fish. This publication is Number 61 within the
Fossils and Strata series. The international
Fossils and Strata series features monographs in palaeontology and biostratigraphy with taxonomic descriptions. The series is owned by and published on behalf of The Lethaia Foundation in cooperation with the Scandinavian countries.
Table of ContentsIntroduction 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
